U.S. patent application number 17/499401 was filed with the patent office on 2022-03-03 for method and apparatus for composite user interface generation.
This patent application is currently assigned to Versata FZ-LLC. The applicant listed for this patent is Versata FZ-LLC. Invention is credited to Donald MacLeod Stewart, Plamen Ivanov Valtchev, Edwin Wilhehmus Petrus Cornelus Van Der Sanden.
Application Number | 20220070122 17/499401 |
Document ID | / |
Family ID | 1000005960237 |
Filed Date | 2022-03-03 |
United States Patent
Application |
20220070122 |
Kind Code |
A1 |
Van Der Sanden; Edwin Wilhehmus
Petrus Cornelus ; et al. |
March 3, 2022 |
Method and Apparatus for Composite User Interface Generation
Abstract
A method for directing messages between a composite user
interface and at least one source application. A message is to be
directed to a predetermined set of services, each service executes
a command specified by the message and the message comprises
details of the predetermined set of services. Each service in the
predetermined set of services uses said details to determine
whether the message should be sent to another service, and if it is
determined that the message should be sent to another service
transmits the message to an appropriate service.
Inventors: |
Van Der Sanden; Edwin Wilhehmus
Petrus Cornelus; (London, GB) ; Valtchev; Plamen
Ivanov; (London, GB) ; Stewart; Donald MacLeod;
(London, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Versata FZ-LLC |
Dubai Media City |
|
AE |
|
|
Assignee: |
Versata FZ-LLC
Dubai Media City
AE
|
Family ID: |
1000005960237 |
Appl. No.: |
17/499401 |
Filed: |
October 12, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16572380 |
Sep 16, 2019 |
11171897 |
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17499401 |
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15479791 |
Apr 5, 2017 |
10419373 |
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16572380 |
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15174291 |
Jun 6, 2016 |
9654429 |
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15479791 |
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13847796 |
Mar 20, 2013 |
9389927 |
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15174291 |
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10584013 |
Mar 5, 2007 |
8407718 |
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PCT/GB03/05662 |
Dec 23, 2003 |
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13847796 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 67/10 20130101;
H04L 51/046 20130101; G06F 9/542 20130101; G06F 9/54 20130101; G06F
2209/547 20130101; H04L 67/26 20130101; G06F 9/546 20130101; G06F
2209/545 20130101; G06F 9/451 20180201; G06F 2209/544 20130101 |
International
Class: |
H04L 12/58 20060101
H04L012/58; G06F 9/451 20060101 G06F009/451; G06F 9/54 20060101
G06F009/54; H04L 29/08 20060101 H04L029/08 |
Claims
1. A method of directing messages within a computer system,
wherein: a message is to be directed to a predetermined set of
services; each service executes a command specified by the message;
the message comprises details of the predetermined set of services;
and each service in the predetermined set of services uses said
details to determine whether the message should be sent to another
service, and if it is determined that the message should be sent to
another service transmits the message to an appropriate
service.
2-146. (canceled)
Description
FIELD OF INVENTION
[0001] The present invention relates to methods and systems for
generating composite user interfaces, and to methods and systems
for directing messages between a composite user interface and a
plurality of source applications.
BACKGROUND OF INVENTION
[0002] Computer users routinely need to use a plurality of
different applications in order to complete tasks allocated to
them, and each application typically has a separate user interface.
Switching between the different user interfaces of the different
applications in order to complete a given task considerably
degrades user efficiency. It will often be the case that different
applications are supplied by different vendors and accordingly
their user interfaces have a different "look and feel", further
degrading operator efficiency.
[0003] For example, in order to process customer enquiries,
operators in a call centre may need to access a customer management
application to access customer details, a billing application to
access customer account information, and a payment application to
process any payment which may be made by the customer over the
telephone, for example by credit card. Working in this manner is
inefficient, given that the operator is required to switch between
applications in order to complete some tasks. Furthermore, a
customer will typically remain on the telephone while the operator
uses these different applications, and it is therefore advantageous
to speed up the processing of enquires, in order to offer a higher
quality customer service.
[0004] Various proposals have been made to enhance user efficiency
when multiple applications need to be used.
[0005] The multiple applications can be combined into a single
product or product suite. While such a proposal provides great
increases in user efficiency, it is difficult and expensive to
implement. Furthermore, such a combined product or product suite
will typically have a different user interface from those used
previously, therefore meaning that users need to be trained in use
of the combined product, further increasing cost.
[0006] It has alternatively been proposed that the multiple
application can be combined in some way. For example, all requests
can be passed to a single one of the applications, and this
application can be adapted to forward requests to an appropriate
source application. Such a solution typically requires considerable
customisation if it is to work in under all circumstances that may
routinely arise, making such a solution difficult to implement.
[0007] It is an object of the present invention to obviate or
mitigate at least some of the problems outlined above.
SUMMARY OF INVENTION
[0008] In accordance with one aspect, the present invention
provides a method and system for processing messages within a
computer system. A message comprising details of a predetermined
set of services and a command is received, and the command is
executed. The message is then transmitted to a service in said
predetermined set of services. In accordance with some embodiments
of the invention, a plurality of services is provided and each
service executes a respective command specified by the message.
Each service in the predetermined set of services uses said details
to determine whether the message should be sent to another service.
If it is determined that the message should be sent to another
service the message is then transmitted to an appropriate
service.
[0009] The present invention thus provides a distributed messaging
method, in which message routing is determined by data contained
within individual messages, and is achieved by the services to
which they are directed. The invention therefore removes the need
for any central messaging service which is responsible for all
message routing operations. In order to allow distributed routing,
the message may comprise an ordered list of pairs, a first element
of each pair representing a service in the predetermined set of
services, and a second element of each pair representing a command
to be executed by that service, thus each service can determine a
command to be executed and can determine a next service to which
the message should be directed.
[0010] The term service is to be understood broadly to cover any
processing means or processing module which is adapted to receive a
message, carry out processing specified by that message, and
forward the message to a further service using data specified
within the message. The services can be implemented using computer
program code means. For example each service can be implemented as
an instance of a class defined in an object oriented programming
language such as Java or C++. Each class representing a service
preferably has an associated service handler class which specifies
a method configured to execute a command directed to an instance of
the respective service class. Advantageously, each service object
references a plurality of service handler objects which are
instances of the respective service handler class. By providing a
plurality of service handler objects in this way, a single service
may carry out a plurality of commands concurrently, thereby
improving processing efficiency.
[0011] In one embodiment, a plurality of services in the
predetermined set of services may operate within a single operating
system process, whilst in other embodiments of the invention some
services in the predetermined set of services may operate within a
plurality of operating system processes. Providing a plurality of
processes enhances scalability, while operating a plurality of
services within a single operating system process can result in
improved performance. It is preferred that an attempt is made to
locate a service within the current operating system process, and
if such an attempt is successful, relatively costly inter process
communication can be avoided. However, if the attempt is
unsuccessful, the message may be transmitted to a messaging service
within the current operating system process which is responsible
for inter-process communication, and the messaging service may
transmit the message to a different operating system process, thus
providing scalability. For example, in some embodiments, the system
and method of the invention allow different services provided on
different computers connected to a computer network to be handled
in a similar manner to different services provided within different
operating system processes on a single computer. It is preferred
that messaging is achieved using the Java Messaging Service
(JMS).
[0012] In some embodiments, a message may be directed between a
composite user interface and at least one source application, such
that the composite user interface can be used to interface with the
at least one source application. A message emanating from a
composite user interface may be directed to a service which
generates at least one further message. The further message may
comprise details of a further set of services to which the further
message is to be directed, and the further message can then be
directed in the distributed manner described above. The at least
one further message may be processed by one of services in said
further set of services to produce a request which is transmitted
to the at least one source application. Messaging methods provided
by embodiments of the present invention offer particular benefits
in composite user interface applications given that communication
between a composite application and one or more source applications
can be provided in a decoupled manner. Thus, the invention allows
composite user interfaces to be conveniently and efficiently
provided allowing users to use a composite user interface to
control a plurality of source applications, offering considerable
benefits in user productivity.
[0013] Data from the source application may be used to create a
response message in response to said request. The response message
can again be handled in the distributed manner described above. An
aggregation service in the set of response services may receive a
plurality of response messages and may combine said plurality of
response messages to create a further response message. Thus, the
aggregation service can effectively combine a plurality of messages
containing user interface elements to create a composite user
interface.
[0014] In some embodiments, the aggregation service may also
generate additional user interface elements which are combined with
said user interface to generate said composite user interface.
Adding additional user interface elements in this way can be useful
in providing a unified "look and feel" throughout a composite
application.
[0015] The aggregation service may combine said user interface
elements to generate the composite user interface in accordance
with predefined configuration data, which can suitably be stored in
a hierarchical data structure. A first entity within the
hierarchical data structure may represent the composite user
interface, and child entities of said first entity may represent
the plurality of source user interface elements for inclusion in
the composite interface. Each child entity of the first entity can
in turn have child entities and so on. Using a hierarchical data
structure is advantageous as it allows easy scalability where user
interface elements are nested within other user interface
elements.
[0016] In some embodiments, each child entity has an associated
parameter indicating whether the respective source user interface
element is mandatory. The aggregation service may receive a user
interface element, store data indicative of receipt of said user
interface element in a data structure associated with said
hierarchical data structure, and when all source user interface
elements having an associated parameter indicating that the source
user interface element is mandatory have been received, combine
said plurality of source data items to generate said composite user
interface. Differentiating between mandatory and non-mandatory user
interface elements in this way can provide considerable benefits in
terms of efficiency, and allows a user interface to be provided as
soon as key components have been received.
[0017] The composite user interface may be generated in an internal
format, which may be converted to an output format using output
configuration data. This allows the invention to be easily adapted
for use with a plurality of different output formats, assuming only
that appropriate configuration data is provided.
[0018] A transformation service may receive data from the at least
one source application and transform said data into an internal
format, said transformed data being contained in said plurality of
response messages. Said transformation may be effected in a
plurality of different ways, for example using regular expressions,
or using a class defined in an object oriented programming language
to transform data.
[0019] In some embodiments, the aggregation service may be
configured to expect to receive a predetermined number of response
messages in response to transmission of said further message, and
said further response message may be generated when the
predetermined number of response messages has been received.
[0020] According to a further aspect of the present invention,
there is provided a method and system for generating a composite
user interface for presentation to a user. The method comprises
generating requests for a plurality data items for inclusion in the
interface, transmitting each request to one of a plurality of
source applications, and combining data items received in response
to at least one of said requests to generate the user interface. At
least some of the predetermined plurality of data items are
mandatory, and at least some of the predetermined plurality of data
items are optional, and the composite user interface is generated
when all mandatory data items have been received. This aspect of
the present invention allows composite user interfaces to be
generated more quickly, given that it is necessary to await receipt
only of mandatory user interface elements.
[0021] The method preferably comprises generating said plurality of
requests from a single request such as a HTTP request entered by a
user using a web browser. The plurality of requests are decoupled
from the single request. Said single request may be received by an
aggregation service functioning in a manner similar to that
described above.
[0022] A further aspect of the present invention, provides a method
for generating a composite user interface for presentation to a
user, said composite user interface comprising a plurality of user
interface elements generated from source interface elements
provided by at least one source application. The method comprises
generating a plurality of request messages, transmitting each
request message to an appropriate source application and receiving
a plurality of source interface elements from the at least one
source application. Source interface elements are compared with a
plurality of predefined source interface templates; and if said
received source interface element matches a predefined source
interface template, at least one user interface element is
extracted for inclusion in said composite user interface. At least
one of said source interface elements may be a HTML document, or a
part of a HTML document such as, for example, a text box, fixed
text data, or buttons responsive to selection by a pointing
device.
[0023] The method may further comprise: creating an internal
representation of each extracted user interface element, forwarding
said internal representations to an aggregation service, and
combining said internal representations to create an internal
representation of the composite user interface. The method may
further comprise transforming said internal representation of the
composite user interface into an output format specified by
predefined configuration data. By using internal representations in
this way, the process of composite user interface creation can be
carried out independently of any required output formats, meaning
that the method can be easily applied to a wide variety of
different output formats (e.g. HTML for a web based output),
assuming only that necessary configuration data is supplied.
[0024] The invention also provides a carrier medium such as a disk
or CD-ROM carrying computer readable program code means for
controlling a computer to carry out any of the methods described
above.
[0025] The invention also provides a computer apparatus comprising
a program memory containing processor readable instructions, and a
processor for reading and executing the instructions contained in
the program memory. The processor readable instructions comprising
instructions controlling the processor to carry out any of the
methods described above.
BRIEF DESCRIPTION OF DRAWINGS
[0026] Embodiments of the present invention will now be described,
by way of example, with reference to the accompanying drawings, in
which:
[0027] FIG. 1 is a schematic overview of a system for composite
application creation in accordance with an embodiment of the
present invention;
[0028] FIG. 2 is a schematic illustration showing the system of
FIG. 1 in further detail;
[0029] FIG. 3 is a schematic illustration of process management
within the server of FIG. 2;
[0030] FIG. 4 is a schematic overview of Java classes used to
implement some parts of the architecture of FIG. 3;
[0031] FIGS. 4A to 4V are UML class diagrams showing the classes of
FIG. 4 in further detail;
[0032] FIG. 5 is a schematic overview of Java classes used to
implement the nodes illustrated in FIG. 3;
[0033] FIGS. 5A to 5J are UML class diagrams showing the classes of
FIG. 5 in further detail;
[0034] FIG. 6 is a state transition diagram showing transitions
between classes of FIG. 5 used to represent state information
related to nodes;
[0035] FIG. 7 is a schematic overview of Java classes used to
implement the services illustrated in FIG. 3;
[0036] FIGS. 7A to 7F are UML class diagrams showing the classes of
FIG. 7 in further detail;
[0037] FIG. 8 is a schematic overview of Java classes class used to
implement messaging within the architecture of FIG. 3;
[0038] FIGS. 8A to 8K are UML class diagrams showing the classes of
FIG. 8 in further detail;
[0039] FIG. 9 is a schematic illustration showing creation of a
process within the architecture of FIG. 3;
[0040] FIG. 10 is a schematic illustration showing creation of a
node within one of the processes of FIG. 3;
[0041] FIG. 11A is a schematic overview of a messaging process in
accordance with an embodiment of the present invention;
[0042] FIG. 11B is a flowchart showing the messaging process of
FIG. 11A in further detail;
[0043] FIGS. 12A to 12D are schematic illustrations showing the
messaging of FIGS. 11A and 11B in further detail;
[0044] FIG. 13 is a schematic illustration showing distributed
messaging as illustrated in FIGS. 12A to 12D;
[0045] FIG. 14 is a schematic illustration of the logical
architecture of the web server and the server of FIG. 2;
[0046] FIG. 15 is a schematic illustration showing how parts of the
architecture of FIG. 14 cooperate to provide composite user
interfaces;
[0047] FIG. 16 is a table showing invocation parameters used by the
web server of FIG. 2;
[0048] FIG. 17 is a table showing invocation parameters used by the
server of FIG. 2;
[0049] FIG. 18 is a table showing Hypertext Markup Language (HTML)
tags which may be used in embodiments of the present invention;
[0050] FIG. 19 is an extract from a configuration file,
illustrating how various parameters can be initalised;
[0051] FIG. 20 is a tree diagram illustrating configuration data
for the server and web server of FIG. 2;
[0052] FIG. 21 is a tree diagram showing configuration data
pertinent to the Communications Layer (CL) services of FIG. 14;
[0053] FIGS. 22 and 23 are tree diagrams showing configuration data
pertinent to the Data Transformation (DT) services of FIG. 14;
[0054] FIGS. 24, 25 and 26 are tree diagrams showing configuration
data pertinent to the User Experience Manager (UXM) service of FIG.
14;
[0055] FIG. 27 is a tree diagram showing configuration data
pertinent to the Application Lockdown Framework (ALF) illustrated
in FIG. 14;
[0056] FIG. 28 is a tree diagram showing configuration data for the
web server illustrated in FIG. 14;
[0057] FIG. 29 shows configuration data for the IDM illustrated in
FIG. 14;
[0058] FIG. 30 is a schematic illustration showing a relationship
between a UXM tree and a UXMObject tree;
[0059] FIG. 31 is a schematic illustration showing how a HTML
document may be converted into a plurality of UXM objects;
[0060] FIG. 32 is a schematic illustration of operation of the DT
service for a particular source application; and
[0061] FIG. 33 is a HTML code fragment which can be used to
generate an IncomingUserRequest message.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0062] FIG. 1 illustrates a system for creating composite
applications in accordance with an embodiment of the present
invention. A first source application provides a first user
interface 1, a second source application provides a second user
interface 2, and a third source application provides a third user
interface 3. A composition system 4 composes the first, second and
third user interfaces to form a first composite user interface 5
and a second composite user interface 6. It can be seen that the
first composite user interface 5 is created from the composition of
the first, second and third user interfaces 1, 2, 3, while the
second composite user interface 6 is created from the composition
of the second and third user interfaces 2, 3.
[0063] The composition system 4 processes requests from users of
the composite user interfaces 5, 6 and generates requests to the
appropriate source applications. The composition system 4
additionally receives information from the first, second and third
applications in response to such requests, and uses this
information to generate the composite user interfaces 5, 6.
[0064] For example, the composite user interfaces 5 may comprise a
number of pages each containing elements from one or more of the
first, second and third user interfaces 1, 2, 3. That is a first
page of the user interface may be made up solely from the first
user interface 1, and a second page may be up from the combination
of part of the second user interface 2 and part of the third user
interface 3, and a third page may comprise part of the second user
interface 2, rearranged by the composer to provided a "look and
feel" which is similar to that of the first and second pages.
[0065] FIG. 2 illustrates the system of FIG. 1 in further detail.
The composite user interface 5 is displayed to a user by means of a
display device 7 connected to a PC 8. Similarly, the composite user
interface 6 is displayed to a user by means of a display device 9
connected to a PC 10. The PCs 8, 10 have means for connection to
the Internet 11. The PCs 8, 10 can be connected to the Internet 11
via a local area network connection, or alternatively via a modem
(not shown).
[0066] A Web server 12 is also connected to the Internet 11, and
stores a plurality of webpages in HTML (Hypertext Markup Language)
format which can be accessed by the PCs 8, 10. The Web server is
connected to a server 13. This connection can either be a direct
connection 14 (as shown in FIG. 2), or alternatively a connection
across a network such as the Internet. The server 13 is in turn
connected to three servers 15, 16, 17 which respectively execute
the first second and third applications to provide the first second
and third user interfaces 1, 2 3. The server 13 is also connected
to a database 18 which stores configuration data.
[0067] In operation, the web server 12 provides HTML documents
which form the composite user interfaces 5, 6. The composite user
interfaces 5, 6 are created by processes running on the server 13,
which create the composite user interfaces from information
provided by the servers 15, 16, 17, in accordance with
configuration data stored in the database 18 as described below.
Data input by users of the composite interfaces 5, 6 is received by
the web server 12 and forwarded to the server 13 via the connection
14. The server 13 processes such data in a predefined manner, and
forwards data to the servers 15, 16, 17 as appropriate.
[0068] It will be appreciated that in some embodiments of the
present invention, instead of connection over the Internet 11, the
appropriate connections can be realised through an organisation's
Intranet.
[0069] Operation of the Web server 12 and the server 13 in creating
and modifying the composite user interfaces 5, 6 is described
below.
[0070] The server 13 operates using a flexible process framework.
FIG. 3 illustrates components used within this flexible process
framework.
[0071] A HostMasterWatchdog component 19 checks if a HostMaster
process 20 is already running, and if not causes a HostMaster
process to be started. The HostMaster process 20 is responsible for
creating and removing processes. The HostMaster process 20 ensures
that all created processes are up and running and also passes
relevant configuration information to such processes. Any host
operating in accordance with the process framework described herein
runs a single instance of the HostMasterWatchdog component 19 and
the HostMaster process 20.
[0072] In the illustration of FIG. 3, a server runs a first process
21 and a second process 22. The first process comprises two nodes
23, 24 and the second process comprises two nodes 25, 26. Nodes are
containers for user services, and are described in further detail
below. Each of the processes 21, 22 includes a respective process
agent 27, 28 which is responsible for starting nodes within the
respective process, and restarting nodes within the process in case
of failure. Operation of nodes within the processes 22, 23 is
managed by respective node manager components 29, 30.
[0073] In preferred embodiments of the present invention all
entities in the framework illustrated in FIG. 3 except the
HostMasterWatchdog 19 are implemented as instances of Java.TM.
classes, thereby providing and object oriented implementation.
Details of such an implementation are described below. In the
following description, programming language constructs such as
classes, objects, interfaces and methods, are given their usual
meaning within the Java programming language.
[0074] The HostMasterWatchdog process 19 regularly checks the state
of the HostMaster process 20. If the HostMasterWatchdog process 19
finds a HostMaster process 20 in an invalid state, or fails to find
a HostMaster process, it attempts to shutdown any existing
HostMaster process 19 and starts a new HostMaster process. If this
is initially unsuccessful, repeated retries are attempted until a
user manually exits the HostMasterWatchdog 19. The
HostMasterWatchdog process 19 is typically written in a
conventional high level programming language such as C, and a
HostMasterWatchdog implementation will therefore need to be written
for each different platform on which the framework is to operate.
However, in preferred embodiments of the invention, the other
components are all implemented as instances of Java classes,
providing portability between platforms.
[0075] FIG. 4 illustrates the classes used to implement other
entities illustrated in FIG. 3. Individual classes are illustrated
in further detail in FIGS. 4A to 4V.
[0076] In addition to the entities illustrated in FIG. 3, each of
the processes 21, 22 maintains a component registry by creating and
maintaining an instance of a DefaultComponentRegistry class 31
(FIG. 4A), which implements a ComponentRegistry interface 32 (FIG.
4B). This registry allows objects to be added to the registry using
a registerObject(Object C) method specified in the
ComponentRegistry interface 32. Objects added to the registry can
be monitored and administered using methods provided by the
DefaultComponentRegistry class 31, and therefore such components
can receive notifications of state changes in other components in
the registry.
[0077] Each of the entities illustrated in FIG. 3 is represented by
a corresponding class shown in FIG. 4. The HostMaster process is
represented by an instance of a HostMaster class 33 (FIG. 4C). The
ProcessAgent process is represented by an instance of a
ProcessAgent class 34 (FIG. 4D), which in turn references an
instance of a NodeManager class 35 (FIG. 4E) by means of a private
variable mNodeManager within the ProcessAgent class 34. The
NodeManager class 35 contains details of individual nodes. Classes
used to represent such nodes will be described in further detail
below.
[0078] Appropriate instances of the HostMaster 33 and ProcessAgent
34 classes set out above are registered with an instance of the
DefaultComponentRegistry class 31. It can be seen that both
HostMaster class 33 and ProcessAgent class 34 implement a
ComponentAware interface 36 (FIG. 4F). This specifies a single
method getComponentClass( ) which all implementing classes must
provide. Each class defines this method so as to locate an
appropriate corresponding component class. In the case of the
HostMaster class 33, a HostMasterComponent class 37 (FIG. 4G) is
located by the getComponentClass( ) method. In the case of the
ProcessAgent class 34, the getComponentClasss( ) method locates the
ProcessAgentComponent class 38 (FIG. 4H).
[0079] The component classes provide a convenient manner for
encapsulating administrative information separately from
functionality. When an object implementing the ComponentAware
interface 36 is registered with the instance of the
DefaultComponentRegistry class 31, the getCompoentClass( ) method
is used to locate the appropriate component class, and this
component class is then instantiated and registered with the
instance of DefaultComponentRegistry. These component classes in
turn links with the respective object which is being
registered.
[0080] It should be noted that all entities to be registered with
the DefaultCompoentRegistry will not necessarily implement the
ComponentAware interface 36. If the DefaultCornponentRegistry
object determines that an object being registered does not
implement this interface, an instance of a GenericComponent class
39 (FIG. 4I) is used to register the object with the
DefaultComponetRegistry object. This class simply allows the object
being registered to be located, but provides no administrative
functions.
[0081] FIG. 4 illustrates the hierarchy of classes used to
represent components. The highest level of the hierarchy comprises
a Component interface 40 (FIG. 4J) which is implemented by a
ComponentBase class 41 (FIG. 4K). The ComponentBase class 41 has
two subclasses, a G2Component class 42 (FIG. 4L) and a
AdminComponent class 43 (FIG. 4M). The AdminComponent class 43 acts
as a superclass for three classes which are used to implement
administrative functions. A CascadingAgentComponent class 44 (FIG.
4N) is used for communication between an instance of the HostMaster
class 33 and an instance of the ProcessAgent class 34. An
HTMLAdaptorComponent class 45 (FIG. 4O) is used by the
HostMasterComponent 37. An RMIConnectorServerComponent 46 (FIG. 4P)
is used by the ProcessAgentComponent 38 for communication via
Remote Method Invocation (RMI) as provided by the Java programming
language. The G2Component class 42 acts as a superclass for
components described above. Specifically, the GenericComponent
class 39, the ProcessAgentComponent class 38 and the
HostMasterComponent class 37 are all subclasses of the G2Component
class 42. Additionally, the G2Component class 42 is a superclass
for a ServiceComponent class 47 (FIG. 4Q), and a NodeComponent
class 48 (FIG. 4R).
[0082] It has been mentioned above that an instance of the
NodeManager class 35 is referenced by a private variable in
instances the ProcessAgent class 34. Both the ProcessAgent class 34
and the NodeManager class 35 both implement a NodeAdmin, interface
49 (FIG. 4S).
[0083] A number of other classes are also illustrated in FIG. 4. A
G2Runtime class 50 (FIG. 4T) is used as a master class for the
runtime of all classes illustrated in FIG. 4.
[0084] A ComponentAddress class 51 (FIG. 4U) is used to address the
components of the architecture of FIG. 3. An exception
AdminException 52 is used for exeptions thrown by subclasses of the
AdminComponent class 43.
[0085] An MBeanConfig class 53 (FIG. 4V) is used to represent
configuration information of an MBean.TM.. The components
implemented as subclasses of the ComponentBase class 41 all inherit
a private variable of type Object which represents an MBean used to
implement that component. The MbeanConfig class 53 represents the
configuration of such MBean objects.
[0086] As described above, the HostMaster process 20 (FIG. 3) is
represented by a HostMaster object, and registered using a
HostMasterComponent object. The HostMasterComponent allows the
HostMaster to be notified of ProcessAgent creation and removal.
This is described in further detail below.
[0087] The ProcessAgent processes 27, 28 (FIG. 3) are represented
by respective ProcessAgent objects which allow administration of
nodes within that process, via appropriate NodeManager
object(s).
[0088] As shown in FIG. 3, processes contain nodes, which are
managed by a NodeManager object. Nodes in turn comprise one or more
services. A node is responsible for its contained services, and
does not directly deliver any user functionality. Each node is
represented by a suitable object, and FIG. 5 shows an overview of
appropriate classes. The individual classes are shown in Further
detail in FIGS. 5A to 5J.
[0089] The NodeManager class 35 instantiates and uses an instance
of a NodeFactory class 54 (FIG. 5A) which creates instances of a
MasterNode class 55 (FIG. 5B), and these instances are used to
represent the nodes 23, 24, 25, 26 (FIG. 3). It should be noted
that the MasterNode class 55 implements a Node interface 56 (FIG.
5C) which specifies methods required to implement basic
functionality. The NodeManager class instantiates instances of a
NodeNotFoundException 35a, when it is requested to act upon a
MasterNode object of which it is not aware.
[0090] Each MasterNode object has associated with it one or more
router threads which are used to route messages within the node.
These threads are represented by a private variable
mRouterThreadPool in the MasterNode class 55, which is an instance
of a class (not shown) implementing a Pool interface 57 (FIG. 5D).
The class implementing the Pool interface contains objects
represented by instances of a RouterThread class 58 (FIG. 5E),
which represent the router threads.
[0091] Each node has associated with it a cache represented by an
instance of a ReplicatedCache class 59 (FIG. 5F) which is a
subclass of a TimeStampedCache class 60 (FIG. 5G), which in turn
implements a Cache interface 61 (FIG. 5H). The purpose of the
ReplicatedCache object is to store state information related to
each service contained in that node, and this information can be
used to restart services in the event of a system crash.
Furthermore, the cache is replicated between multiple nodes, such
that if one node crashes, the node and its associated services can
be restarted using cache data from the node containing the copy of
the cache data. The ReplicatedCache class 59 provides methods to
ensure synchronisation of data in the copy cache.
[0092] Each node also comprises an addressable registry,
represented by an instance of the ComponentRegistry class 62 (FIG.
5I) This class allows services within a node to be registered with
the node, and also provides look up functions which can be used to
locate services present within the node.
[0093] A node represented by a MasterNode object can have one of
eight possible states, each of which is represented by a
corresponding class. The private variable mState indicates an
object indicating this state information. Each of the eight classes
which may be stored in the mState variable implements the Node
interface 56 which specifies methods relevant to transitions
between states.
[0094] The state information is infact represented by instances of
classes which are subclasses of an AbstractNode class 63 (FIG. 5J)
which itself implements the node interface 56.
[0095] A class CreatedNode 64 represents a node which has been
created but not yet initialised. A class InitializedNode 65 is used
to represent a node following initialisation. A class StoppedNode
66 represents an initialised node which is not currently running.
When a node is starting, its state is represented by a class
StartingNode 67. A class RunningNode 68 represents a node which has
been started and is running. A node which is about to stop running
is represented by a StoppingNode class 69. Classes FailedNode 70
and RecoveringNode 71 are used to represent node failure. Each of
these classes specifies a constructor method taking as its sole
parameter the MasterObject to which it belongs, and the also
provides five methods specified in the Node interface 56--init( ),
start( ), stop( ), destroy( ), recover( ). Each class representing
state therefore provides a number of methods to allow state change.
For each state, only a single method will not throw an
InvalidStateException when called.
[0096] Transitions between the states represented by the objects
set out above are now described with reference to FIG. 6. Upon
construction of a MasterNode object by instantiation of the
MasterNode 55 by the NodeFactory 54, the mState variable points to
an instance of the CreatedNode class 64.
[0097] Calling the init( ) method provided in the CreatedNode class
creates an instance of InitializedNode 65, which is referenced by
the MasterNode to represent state. When initialisation is complete
an instance of the StoppedNode class 66 is created by the
InitializedNode instanvce. Calling the start( ) method provided by
the StoppedNode class 66 causes an instance of the StartingNode
class 67 to be created which is then referenced by the MasterNode
to represent state. The StartingNode class then creates an instance
of the RunningNode class 68. The only method which provided by the
RunningNode class 68 which does not throw the InvalidStateException
is the stop( ) method. When this is called an instance of the
StoppingNode class 69 is created, and subsequently a further
instance of the StoppedNode class 66 is created to represent
state.
[0098] If processing causes an uncaught exception to be thrown, an
instance of the FailedNode class 70 is created. The only method
which can then be vailidly used is recover( ) which creates an
instance of the class RecoveringNode 71, before creating an
instance of the class StoppedNode 66.
[0099] Referring back to FIG. 5, it can be seen that the MasterNode
class 55 implements a NodeStateSource interface 72 which allows
instances of a NodeStateListener class 73 to be registered as
listeners with MasterNode objects.
[0100] The preceding description has been concerned with the
implementation of Nodes. It has been described that nodes contain
services, and appropriate services are now described. Services are
managed by a node, and receive and process messages which are sent
to them. The class hierarchy used to implement services is now
described with reference to FIG. 7. Further details of the classes
shown in FIG. 7 are shown in FIGS. 7A to 7F.
[0101] Each service is implemented as an object which is an
instance of a BaseService class 74 (FIG. 7A), or as an instance of
a subclass thereof. The BaseService class 74 implements an
Addressable interface 75, which specifies a single getAddress
method. In the case of the BaseService class 74, it can be seen
that a service's address is stored as a private variable of type
ComponentAddress (shown in FIG. 4)
[0102] The BaseService class 74 additionally implements a
HandlerContext interface 76 (FIG. 7B) which specifies features
which allow service handlers represented by instances of the
BaseServiceHandler class 77 (FIG. 7C) to be provided within a
service to provide functionality. Handlers receive messages
addressed to a service, and act upon those messages. Thus, handlers
provide the functionality of a service. Each service will have a
predetermined handler class which provides handlers, and this class
will be a subclass of the BaseServiceHandler class 77. Each service
may have a plurality of instances of the handler class, thus
allowing a service to process messages from a plurality of users
concurrently.
[0103] It can be seen that the BaseServiceHandler class 77
implements a MessageHandler interface 78 which allows handling of
messages in a unified manner by specifying a single handleMessage(
) method. The BaseServiceHandler class 77 also implements a
ResultListener interface 79 which specifies a single method
deliverResult.
[0104] Instances of the BaseService class 74 use instances of a
MessageDispatcher class 80 (FIG. 7D) to dispatch messages within
and between services. Both the BaseService class 74 and the
BaseServiceHandler class 77 implement a MessageRouter interface 81,
which allows routing of messages between services using a route( )
method. This interface is used by the MessageDispatcher class 80.
Routing of messages using these classes is described in further
detail below.
[0105] It can be seen that FIG. 7 additionally illustrates a
ServiceFactory class 82 (FIG. 7E) which is used to create services,
and a Service State class 83 (FIG. 7F) which is used to denote the
state of an instance of the BaseService class 74 or one of its
subclasses. FIG. 7 also illustrates a DebugHandler class 84, which
is a service handler used for debugging purposes during
development.
[0106] FIG. 8 illustrates a hierarchy of classes used to implement
messages which can be passed between services to be handled by
appropriate service handlers. These classes are shown in further
detail in FIGS. 8A to 8K.
[0107] Referring to FIG. 8, it can be seen that the hierarchy used
to represent messages is headed by a Message interface 85 (FIG. 8A)
which is implemented by an abstract class AbstractMessage 86 (FIG.
8B). A ComandSequenceMessage class 87 (FIG. 8C) extends the
AbstractMessage class 86. An instance of the CommandSequenceMessage
class 87 represents messages which are to be transmitted between
services. The CommandSequenceMessage class has four subclasses
representing messages used in preferred embodiments of the present
invention. A UserRequest class 88 (FIG. 8D) is used to represent
messages generated by a user. A UserResponse class 89 (FIG. 8E) is
used to represent responses to messages represented by instances of
the UserRequest class 88. An ApplicationRequest class 90 (FIG. 8F)
is used to represent requests made using Application Programmers'
Interface (API) calls, and an ApplicationResponse class 91 is used
to represent response to messages reqpresented by the
ApplicationRequest class 90.
[0108] Each of the message types described above inherits core
features required to implement messaging from the
CommandSequenceMessage class 87 (FIG. 8C). A private mSequence
variable within the CommandSequenceMessage class 87 references an
instance of a CommandSequence class 92 (FIG. 8H). The
CommandSequence class includes an array of pairs which comprise a
command, and a target (that is a service to which that command is
targeted). Each command target pair is represented by an instance
of a CommandTargetPair class 93 (FIG. 8I). It can be seen that
CommandSequence acts as a superclass for a
UserRequestCommandSequence class 94, a UserResponseCommandSequence
class 95, an ApplicationRequestCommand-Sequence class 96 and an
ApplicationResponseCommandSequence class 97. Each of these
subclasses of the CommandSequence class 92 represents a command
sequence appropriate to the corresponding subclass of the
CommandSequenceMessage class 87.
[0109] The state of any message represented by a subclass of the
AbstractMessage class 86 is represented by a private mState
variable which references an instance of a MessageState class 97
(FIG. 8J).
[0110] The CommandSequenceMessage class 87 also has as a subclass a
SingleCommandMessage class 98 (FIG. 8K) which represents a message
having a single command and a single target. The
SingleCommandMessage class in turn has a SystemRequest class 99a
and a ServiceRequest class 99b as subclasses.
[0111] Having described the various classes used to implement that
which is illustrated in FIG. 3, and having also described the
classes used to implement messaging, the manner in which the
components of FIG. 3 operate together and the manner in which
messaging is achieved is now described with reference to FIGS. 9 to
13. In the following description, objects are denoted by the
reference numerals followed by a prime symbol ('). Where
appropriate, reference numerals associated with the class of which
an object is an instance are used.
[0112] Referring first to FIG. 9, creation of ProcessAgents in the
architecture of FIG. 3 is illustrated. As described above a
HostMasterWatchDog process 19 creates a HostMaster object 33'. The
HostMaster object has associated with it a G2Runtime object 50'
which can be used to locate a DefaultComponentRegistry object 31'
using a getComponentRegistry( ) method. The HostMaster object 33'
is then registered within the DefaultComponentRegistry object 31'
this in turn creates a HostMasterComponent object 37'.
[0113] The HostMaster uses configuration data to determine how many
ProcessAgent objects it needs to create. For each ProcessAgent
object which is to be created, a CascadingAgentComponent 44' is
created, and this component in turn communicates with a respective
ProcessAgent object 34' which is created within its own Java
Virtual Machine. The main ( ) method of the ProcessAgent object 34'
is configured to carry out the work of the Process Agent. The
ProcessAgent object 34' has an associated G2Runtime object 50''
which is used to locate a DefaultComponentRegistry object 31''.
This in turn creates a ProcessAgentComponent object 38'.
[0114] The Component objects created by instances of the
DefaultComponentRegistry class as described above allow
administration of both HostMaster and ProcessAgent objects. As
described above both the HostMaster object 33' and the ProcessAgent
object 34' have associated DefaultComponentRegistry objects 31' and
31'', and both these DefaultComponentRegistry objects store details
of both the HostMasterComponent object 37', and the
HostMasterComponent object 38'
[0115] The CascadingAgentComponent object 44' and the ProcessAgent
object 34' communicate using RMI, and both have RMI clients which
are used for this purpose. As described above, a HostMaster object
is responsible for management of its associated ProcessAgent
objects. This is achieved by communication using the component
registries described above. Furthermore, a ProcessAgent object may
generate "Heart beat" events at predetermined intervals, and the
HostMaster object may listen for such events. If such an event is
not received at the expected time, or within a predetermined time
after the expected time, the HostMaster object then assumes that
the ProcessAgent object has died, and accordingly performs recovery
by instantiating a new ProcessAgent object. Details of the death of
the earlier ProcessAgent object and creation of the new
ProcessAgent object are recorded in the appropriate
DefaultComponent registry objects.
[0116] FIG. 10 illustrates the process of node creation within a
particular process. The ProcessAgent object 34' locates its
NodeManager object 35' (referenced by the mNodeManager private
variable). It then uses a public createNode method within the
NodeManager object 35' to create a node. The createNode method
takes as a parameter a node type, which is represented by a
NodeType object which is an index and textual description of the
node to be created. The NodeManager object 35' creates a
NodeFactory object 54' using its constructor which takes no
parameters. The createNode method provided by the NodeFactory
object 54' is then used to create the desired node. The NodeFactory
object 54' creates a MasterNode object 55' by calling its
constructor method which takes no parameters.
[0117] The MasterNode object 55' in turn instantiates a CreatedNode
object 64' which is referenced by an mState parameter within the
MasterNode object 55'. An init( ) method provided by the
CreatedNode object 64' is then called by MasterNode to initialise
the MasterNode object 55', and the transitions between states
illustrated in FIG. 6 can then occur as necessary, and the state of
the node is set using a setState method provided by the MasterNode
object 55'. The CreatedNode object 64 in due course uses a
ServiceFactory object 82' to create the services required by the
MasterNode object 64'.
[0118] It can be seen from FIG. 4E that the NodeManager class
includes a private Vector variable mynodes which stores details of
all nodes managed by a NodeManager object. FIG. 10 schematically
illustrates that each time a MasterNode object is created, it is
added to this vector variable.
[0119] FIGS. 11A and 11B show how messages are transmitted from a
first service 74' to a second service 74'' in accordance with an
embodiment of the present invention. Referring to FIG. 11A it can
be seen that the first service 74' comprises a plurality of service
handlers 77' which provide the functionality of the first service
as described above. The first service 74' additionally comprises an
in queue IN1 into which incoming messages are placed, and an out
queue OUT1 into which outgoing messages are placed prior to
transmission. The second service 74'' comprises a plurality of
service handlers 77'', an in queue IN2 and an out queue OUT2. Both
the first service 74' and the second service 74'' have associated
with them unique addresses which are used for directing messages to
them.
[0120] FIG. 11B illustrates how messaging is effected using the
structure illustrated in FIG. 11A. FIG. 11B illustrates routing of
a message from one of the service handlers 77' of the first service
74' to one of the service handlers 77'' of the second service 74''.
At step S1, a service handler 77' of the first service 74' executes
the command specified in the message. When this execution is
complete, the service handler 77' interrogates the message to
determine an address mask of the next service to which it is to be
sent, and modifies the message to show this address mask (step S2).
At step S3, the message is sent to the out queue OUT1 of the first
service 74'. A MessageDispatcher object associated with the out
queue OUT1 then copies the message to its wait queue (step S4), and
interrogates the message to obtain an address mask indicating the
message's intended destination (step S5). At step S6, a
ComponentRegistry object is used to locate all services within the
current operating system process which match the message's address
mask.
[0121] At step S7, a check is made to determine whether or not any
services have been located. If it is determined that a single
appropriate service has been located (e.g. the second service 74''
of FIG. 11B), the message is forwarded to the in queue of that
service (step S8), an appropriate service handler is located within
that service (step S9), and the message is forwarded to the located
service handler.
[0122] If step S7 determines that no suitable service can be found
within the current process, the message is amended to show that it
must be directed to a messaging service which can carry out
inter-process messaging (step S11). An appropriate messaging
service is then found (step S12), the message is directed to the in
queue of the messaging service (step S13) and the messaging service
then carries out inter-process communication (step S14).
[0123] If step S7 locates N suitable services, where N is greater
than one, a counter variable, m is initialised to zero, (step S15),
and then a sequence of operations are carried out N times by the
action of a loop established by steps S16 and S21. Each loop will
produce a clone of the message (using standard Java functionality)
at step S17 and this is sent to one of the located services at step
18, A suitable service handler is then located within each service
(step S19) and appropriate processing is carried out (step
S20).
[0124] FIGS. 12A to 12D illustrate messaging in further detail.
[0125] Referring to FIG. 12A, it can be seen that a CommandExecutor
object 77b' (referenced by an appropriate variable in an
appropriate handler class) uses an execute method provided by a
command stored in a Command variable within a message 88a'. In the
example illustrated in FIG. 12A the command is a
ReceiveUserRequestCommand, which in turn is handled by a connection
handler object 77c'. It is at this stage that service and message
specific processing takes place. Assuming that the command is
correctly executed, the CommandExecutor object 77b' uses a
commandSucceded method provided by the message 88a'. It can be seen
that this method is provided by the AbstractMessage class (FIG.
8B), and all messages are instances of subclasses of the
AbstractMessage class. In the case of a CommandSequenceMessage, the
commandSucceded method will cause a CommandTargetPair variable
m_ProcessingDelivery to be set to the next command, and the next
target address. When this is complete, a SendServiceMessage method
provided by a ConnectionService object 74a' is used to direct the
message to the service's out queue (represented by an mOutQueue
variable in the BaseService class), using a put method. Thus FIG.
12A illustrates the steps required to place a message in a
service's out queue.
[0126] Referring to FIGS. 8B and 8C it can be seen that a
CommandSequenceMessage object comprises a command sequence (which
is an instance of a CommandSequence object, FIG. 8H), and three
CommandTargetPair objects. A first CommandTargetPair is set set in
the case of success as described above using the commandSucceded
method. A second CommandTargetPair is set in case of failure by a
commandFailed method, and a third CommandTargetPair is used where
communication is required between processes, as is described below
with reference to FIG. 12D. State information within a message
object is used to determine which of the CommandTargetPair objects
should be used at a particular time.
[0127] FIG. 12B illustrates steps which are carried out after a
message has been placed in a service's out queue. The out queue of
the service is provided with its own MessageDispatcher object 80',
which implements the Thread interface provided by the Java
programming language. A get( ) method provided by a WaitQueue is
called by a MessageDispatcher object 80'. The get( ) method
transfers the message to a queue represented by an mWaitQueue
object 80a' within the Message dispatcher object 80'. The
MessageDispatcher object 80' then locates an appropriate MasterNode
object 55', and routes the message to that node.
[0128] On receiving the message, the MasterNode object 55' locates
a RouterThread object 58' from its pool of router threads
(represented by an instance of a class implementing the Pool
interface illustrated in FIG. 5D.), using a getRouterThread method.
Having located a suitable RouteThread object, a route method
provided by a RouterThread object 58' is used to route the message
to the correct service. This involves calling the getAddressMask
method provided by the Message object to obtain an address mask,
and then using a ComponentRegistry object 31' to locate all
services matching the obtained address mask by calling a
findLocalAddressables method provided by the ComponentRegistry
object 31'. Assuming that at least one suitable service is found, a
getRouter( ) method is called on the Service object 74b'. A route(
) method provided by the Service object 74b' is then used to route
the message to out queue 74c' of the Service object 74b'.
[0129] If no suitable services are located by the
findLocalAddressables method, the processing illustrated in FIG.
12D is carried out, as described in further detail below.
[0130] If more than one service is found within a node which
matches the specified address mask, then the message is cloned and
sent to the in queues of all services in the manner described
above. Furthermore, it should be noted that as soon as the message
is dispatched to the RouterThread object 58' the work of the
MessageDispatcher object is finished, thus operation of the
MessageDispatcher object 80' is decoupled from operation of the
RouterThread object 58'.
[0131] FIG. 12C illustrates processing when a message has reached a
service's in queue. A MessageDispatcher object 80b' is associated
with the in queue and listens for message arrivals. When a message
arrives, the MessageDispatcher object 80b' uses a get( ) method to
copy the message to its WaitQueue object 80c'. A route method is
then used to forward the message to a MessageToHandlerForwarder
object 80d'. The MessageToHandlerForwarder object 80d' uses a
getObject method provided by a ServiceHandlerPool object 80e', to
provide a Handler object 77d'. The MessageToHandlerForwarder object
80d' then call a handleMessage method (specified in the
MessageHandler interface) to cause the message to be handled. In
due course the Handler uses a setNextCommand method provided by a
CommandExecutor object 77b' to cause the command sequence to be
suitably updated.
[0132] FIG. 12D illustrates the processing shown in FIG. 12B,
modified where it is the case that the RouterThread object 58'
determines that there are no services registered with the
ComponentRegistry 31' which match the specified address mask. In
this case, a leaveProcess method is used to update the internal
state of the message object 88a', and the RouterThread then seeks
to locate a service which is responsible for inter-process
communication by using a getAddressMask method and a
findLocalAddressables method, which will return an appropriate
service 74d'. Having located an appropriate service the message is
sent to that service in the manner described above with reference
to FIG. 12B. On receipt of the message an the In queue of the
service, the service handles the message (as described with
reference to FIG. 12D), and inter-process communication is thus
achieved.
[0133] From the preceding description, it can be seen that message
routing is carried out as specified within appropriate variables of
a given message. There is no central control of message routing,
but instead control is distributed between objects which handle
messages.
[0134] For example, referring to FIG. 13, there is illustrated a
system of five message handlers denoted A, B, C, D and D'. The
message handlers D and D' are both instances of a common message
handler.
[0135] A message Msg1 is sent from handler A, to handler B, and
subsequently from handler B to handler C. Handler C processes Msg1
in a predetermined manner, and generates two messages, Msg2 and
Msg3. Each of these messages is then routed independently. The
message Msg2 is routed to handler D while the message Msg3 is
routed to the handler D'.
[0136] Each handler processes the message, and routes the message
onwards to the next service specified therein. Distributing control
of message routing in this way provides a scalable system, and
removes the need for any centralised control of messaging. This is
particularly beneficial where a handler creates a plurality of
messages from a single received message (as in the case of handler
C in FIG. 13).
[0137] Referring back to FIG. 2, having described a framework for
operation of the server 13. operation of the webserver 12 and
server 13 to provide composite user interfaces is now
described.
[0138] FIG. 14 illustrates the logical architecture of the web
server 12 and the server 13. It can be seen that the server 13
operates using a process framework as illustrated in FIG. 3, and
comprises a Host Master Watchdog process 100, a Host Master process
101 and a process 102.
[0139] The process 102 comprises a process Agent 104 and a Node
Manager 105 which perform functions as described above. The process
102 comprises three nodes 106, 107, 108. A client adaptor (CA) node
106 is responsible for interaction between the server 13 and the
composite application(s). An application adapter (AA) node 107 is
responsible for interactions between the server 13 and the
appropriate source applications via a source application interface
109. An ALF (Authentication Lockdown Framework) node 108 is
responsible for authentication and security functionality provided
by the server 13. Security information is stored in a database 110
which is accessed via a conventional Java Database Connectivity
(JDBC) interface 111. The function of each of these nodes is
described in further detail below.
[0140] The server 13 is connected to an administration terminal 112
via a link 113. The administration terminal 112 allows
administrators of the server 13 to perform various administration
functions, as described below.
[0141] Configuration data for the nodes 106, 107 is obtained from
an Integration Data Manager (DM), which comprises a database 115
accessed via an appropriate interface (such as JDBC interface 116).
The form of the configuration data, and the manner in which it is
used is described in further detail below. It should be noted that
the database 110 and the database 115 together make up the
configuration data 18 of FIG. 2.
[0142] The Webserver 12 communicates with the server 13 via a
connection 14. The webserver runs a Java.TM. servlet 117, and this
servlet 117 is responsible for communication between the webserver
12 and the server 13. In many situations is necessary to impose
restrictions on access to composite applications or parts of
composite applications managed by the server. Such restrictions can
be conveniently implemented by allocating user names and passwords
to users, and associating appropriate access privileges with such
usernames and passwords. The servlet 117 implements any necessary
security policies, by cooperating with the CA node 106. The
functionality provided by the servlet 117 is referred to as a User
Agent (UA) service.
[0143] The CA node 106 comprises four services. A Messaging layer
(ML) service 118 provides Java Messaging service (JMS)
functionality for communication between objects within different
processes. The JMS is such that messaging between processes can be
carried out in a unified manner, regardless of whether processes
are located on the same or different hosts.
[0144] A Communications Layer (CL) service 119 provides connections
between the CA node and other processes. A Data Transformation (DT)
service 120 provides means to transform data from one form to
another. Such a service can be required both when receiving user
data from a composite application which is to be forwarded to a
source application, and when receiving data from one or more source
applications which is to be output to a composite application. A
User Experience Manager (UXM) service 121 is responsible for
determining the action necessary when requests are received from
the webserver 12, and when data is received from a source
application.
[0145] The AA node comprises three services an ML service 122, a CL
service 123 and a DT service 124. Each of these services provides
the same functionality as the equivalent service of the CA node
106.
[0146] The ALF node 108 again comprises an ML service 125 and an
ALF service 126. The ALF service 126 is responsible for security
features as is described in further detail below.
[0147] The use of the CA node 106 and the AA node 107 to produce
and manage composite applications is now described with reference
to FIG. 15. A user operates a web browser 126 to access HTML
documents provided by the web server 13 which make up a composite
user interface. A user issues a request via the web browser 126.
This request is forwarded to the webserver 12 using the Hyper Text
Transfer Protocol (HTTP) operating in a conventional manner. The
servlet 117 within the web server 12 operates a UA service 127. The
UA service 127 authenticates the request in accordance with
predetermined security policies (defined as described below). If
the authentication is successful, an IncomingUserRequest message is
created using parameters received by the UA (e.g. from the HTTP
request). This IncomingUserRequest message is then sent by the UA
service 127 to the server 13, having a target address of the CL
service 119 of the CA node 106. As described above, this message is
transmitted using the JMS protocol. The CL service 119 receives the
IncomingUserRequest message, and having received the message,
directs it to the DT service 120 of the CA node 106. The DT service
120 performs any necessary transformation of data contained in the
IncomingUserRequest message, and directs the message onwards to the
UXM service 121 of the CA node 106. The UXM service 121 processes
the message and generates one or more OutgoingUserRequest messages,
destined for the appropriate source application(s) 128. These
messages are first sent to the DT service 124 of the AA node 107
using, for example, the JMS protocol.
[0148] The DT service 124 of the AA node 107 performs any necessary
transformation, and forwards the message to the CL service 123,
which in turn generates messages to request appropriate data from
the source application(s) 128 in an appropriate format. These
messages are then forward to the Source Application(s) using, for
example, the JMS protocol.
[0149] The Source application(s) 128 process received messages and
in turn produce data in response to the received request. This data
is received by the AA node 107, and passed to the CL service 123.
The data is then forwarded to the DT service 124 which processes
the data to extract one or more page objects and to create an
IncomingUserResponse message which is forwarded to the UXM service
121 of the CA node 106.
[0150] The UXM service 121 processes the IncomingUserResponse
message, and determines whether or not it has received all data
necessary to create a composite page (determined by its
configuration, which is described below). When all data required is
received, an OutgoingUserResponse message is created which is
forwarded to the DT service 120 where any necessary transformation
is carried out. Having performed any necessary transformation the
OutgoingUserResponse message is forwarded to the CL service 119 and
then onwards to the ML service. The ML service transmits the
composite page to the UA 127 using the JMS protocol. The UA then
displays the page to the user via the web browser 126, assuming
that any necessary validation is successfully carried out by the UA
127.
[0151] In the description presented above, a distinction is made
between IncomingUserRequest messages and OutgoingUserRequest
messages. A similar distinction is made between IncomingUserReponse
messages and OutgoingUserResponse messages. These distinctions are
made to aid understandability, however it should be appreciated
that in some embodiments of the invention both IncomingUserRequest
messages and OutgoingUserRequest messages are represented by a
single UserRequest message type. Similarly both IncomingUserReponse
messages and OutgoingUserResponse messages may be represented by a
single UserResponse message type.
[0152] It will be appreciated that the processing described above
can be used to handle a wide range of different composite
applications, however it will also be appreciated that the
processing required will vary considerably, and therefore an
effective means of configuring the services illustrated in FIGS. 14
and 15 is required. This is achieved by accessing the IDM database
115. IDM data is stored in a hierarchical manner as will be
described in further detail below.
[0153] At startup, the web server 12 and the server 13 need to be
provided with data which allows access to the IDM database, and
indicates where in that database the appropriate data is located.
This is achieved by providing each with appropriate invocation
parameters which indicate where the configuration data can be
located.
[0154] The servlet 117 of the webserver 12 (referred to as "the
listener") is provided with invocation parameters as illustrated in
FIG. 16.
[0155] A g2jms.config parameter specifies a file containing JMS
configuration properties for the servlet 117. A g2config.home
parameter specifies a directory containing an IDM properties file,
which provides information as to how the IDM database 115 is
accessed. A g2listener parameter specifies a node in the
hierarchical IDM data structure where configuration information for
the UA service 127 is located. A g2config.instance parameter
species configuration data for the composite application which the
webserver 12 is to provide to a user. A g2jms.config parameter
specifies configuration for the JMS service of the UA 127. A
g2tracer.conf parameter specifies logger configuration.
[0156] The nodes and services of the server 13 (collectively
referred to as "the composer") are provided with invocation
parameters are illustrated in FIG. 17.
[0157] The g2config.home, g2jms.config and g2config.instance
parameters perform functions as described with reference to FIG.
16. The g2config.webhost parameter specifies an IP address for the
web server on which the UA service 127 is implemented by means of
the servlet 117. The g2config.baseipport parameter specifies a port
number used by an administration console which is used in
connection with the composer as described below. The
g2basetracer.conf parameter is used to specify a log file for each
process operating within the composer. Given that every composer
comprises at least a HostMaster process and a process containing AA
and CA nodes, at least two log files must be specified, in addition
to a log file for the web server.
[0158] The parameters described above with reference to FIGS. 16
and 17 together allow the listener and the composer to obtain
configuration data from the IDM. Additional invocation parameters
are illustrated in FIG. 18. These specify page tags which are used
in HTTP requests passed to the listener by the composer.
[0159] APPLICATION_CLASS specifies a name used for the composite
application, and is used by the composer to determine any
transformation that the CA.DT may be required to perform.
UXM_TREEID and UXM_NODEID specify where in the configuration the
UXM can find configuration information pertinent to the specific
composite page. UXM_MODIFIED allows the UXM to perform no
processing on some pages. If UXM_MODIFIED is set to true, this is
an indication that processing is required in accordance with the
configuration data stored in the IDM (described below). If
UXM_MODIFIED is set to false, this means that no processing is
required and the UXM simply forwards the message to the AA
node.
[0160] Additional tags are used for security purposes. A
g2authorization tag is used to indicate that the listener should
attempt authentication. usr and pwd tags are respectively used to
represent user name and password data when this is required for
authentication.
[0161] The invocation parameters described above allow the composer
and the listener to locate the IDM and to locate suitable data
within the IDM. These parameters are conveniently implemented as
variables of appropriate Java classes. They can be configured by
means of a system.properties file, an example of which is
illustrated in FIG. 19. Each line of the file corresponds to a Java
property to be set. It can be seen that all entries of the file are
prefixed by either `hm` or `pa`. This ensures that each entry is
picked up by the correct process. Entries prefixed by `hm` are
picked up by the HostMaster process, and it can be seen that these
correspond to the composer invocation parameters described above.
Entries prefixed by `pa` are additional properties to be set in
each process set up by the HostMaster process. These typically
include configuration for various aspects of the Java Virtual
Machine (JVM) such as garbage collection.
[0162] It can be seen that in FIG. 19, all entries which begin `pa`
are of the form `pa.x`. This indicates that the property should be
set on all processes started by the HostMaster. However, in some
embodiments of the invention entries may be prefixed by `pa.N`
where N is an integer. In this case, that entry refers only to
process N.
[0163] It should be noted that the system.properties file is used
in a hierarchical manner as follows. Any entry of the form `pa.N`
will override a `pa.x` entry for process N. Any entry of the form
`pa.x` will override the `hm` entry inherited from the HostMaster
process. In addition to setting parameters by means of the
system.properties file, it should be noted that configuration
parameters can be specified at start up, for example via a command
line interface. In such a case, if a property value is specified
both in the system.properties file and on the command line, the
system.properties file will determine the value.
[0164] Having described invocation parameters, and associated tags,
the structure of IDM data stored in the database 115 is now
described.
[0165] It should be noted that, as will become apparent below,
every composite application has a unique application class name
which is used to identify it. Every source application also has an
unique application class name which is used for identification.
Thus, if a composite application is made up of two source
applications, its configuration will include three application
class names.
[0166] A partial IDM structure for a configuration containing a
single process containing an AA node and a CA node (as illustrated
in FIG. 14) is shown in FIG. 20. The highest level of the hierarchy
comprises a single entity CONFIG 129 which is the root of the IDM
tree. This entity has six child entities. An entity INSTANCE 130 is
concerned with configuration information for a particular composer
configuration. An entity BASE_ALF_CONFIG 131 provides configuration
information for an ALF node. Entities HOST 132, PROCESS 133, NODE
134, and SERVICE 135, each have children containing configuration
information for the corresponding entities of FIG. 14.
[0167] As described above, the g2instance parameter references a
named node in the IDM that contains appropriate configuration data.
This data will include details of the number of processes that
should be used, the allocation of CA nodes, AA nodes and ALF nodes
to those processes, and locations where data appropriate for the
services contained within those nodes can be found.
[0168] In this case the g2instance invocation parameter is set such
that:
g2instance=LAB1_INS
[0169] This indicates that the composer should locate the LAB1_INS
entity 136 which is a child of the SINGLE_PROC_AA_CA_INSTANCE 130a,
which is itself a child of the instance entity 130a to obtain
configuration data. It can be seen that the LAB1_INS entity has
suitable data provided by a g2config data group 137.
[0170] The entry alf in the data group 137 indicates that server
uses the ALF, and provides means for locating the ALF database 110
(FIG. 14). The entry host indicates that the server 13 comprises a
single host referenced by that entry in the data group 137. It can
be seen that all other entries are of the form "host.process1.".
Each of these entries provides details of a respective node or
service operating within the single process 102 (process1), on the
server 13 of FIG. 14. It can be seen that every node and service
illustrated in FIG. 14 has a corresponding entry in the data group
137, which provides details of its configuration.
[0171] Configuration of the CL service 123 of the AA node 107 (FIG.
14) is now described. FIG. 21 shows part of the hierarchy of FIG.
20 in further detail, together with details of entities relevant to
the configuration of the CL service 123 of the AA node 107. In
addition to the entities described above, the hierarchy comprises a
BASE_CL_SERVICE entity 138 which is a child of the SERVICE entity
135. The BASE_CL_SERVICE entity 138 has two child entities, a
AA_CL_SERVICE entity 139 which represents the CL service 123 of the
AA node 107, and an EXT_APPS entity 140 which contains details of
relevant source applications. It should be noted that the
hierarchical arrangement of the IDM allows child entities to
inherit and override properties of their parent entity. For
example, default data for all services may be specified in the
SERVICE entity 135. Some this data may be inherited and used by the
BASE_CL_SERVICE entity 138, while other parts of the data may be
replaced by more appropriate values specified in the
BASE_CL_SERVICE entity 138.
[0172] It can be seen that the host.processxAA.CL entry in the data
group 137 references a data group g2config 141 under a mysrcapps
entity 142. The g2config data group 141 includes an entry for every
source application with which the AA communicates, and each
application is referenced by its application class name. Each entry
will include a session timeout parameter which indicates a time
(e.g. in minutes) which a user can be inactive without a connection
being terminated, and a replicate_sessions parameter which is a
Boolean indicating whether or not session data should be copied
between processes. Setting this parameter to TRUE provides fail
over if session data is lost for any reason.
[0173] The source applications from which the composite application
is created are each represented by a child entity of the EXT_APPS
entity 140. In FIG. 21, two source applications are illustrated. A
first source application (having a class name "SrcApp1") is denoted
by an entity SrcApp1 143 and a second application (having a class
name "SrcApp2") is denoted by an entity SrcApp2 144.
[0174] Each of these entities has two data groups. The SrcApp1
entity 143 has a g2config data group 145 which is referenced by the
data group 141 and which specifies data for the configuration of
the AA, and a connection data group 146 which specifies
communications protocols for communication with the SrcApp1
application. The entity SrcApp 2 144 has two similar data groups
147, 148.
[0175] The data stored in relation to each source application is
now described. The g2conifg data group for each source application
145, 147 includes a number of parameters. An authorization
parameter takes a Boolean value and indicates whether or not the
source application requires authentication. A credential_type
parameter is required when the authorization parameter is set to
TRUE. The credential_type parameter is either set to USRPWD or
DYNAMIC. When creditial_type is set to USRPWD, a static username,
password combination is used for authentication. When credential
type is set to DYNAMIC, a static username and dynamically created
password is used for authentication. For example, a password can be
dynamically created from a user name using a predetermined
algorithm. A protocol parameter indicates a protocol to be used for
communication with the source application. Suitable protocols may
include HTTP, SOAP, MQSERIES and JDBC. Other parameters provide
information as to how errors should be handled.
[0176] The connection data group associated with each source
application 146, 148 stores information related to each connection.
It can be seen from FIG. 21 that the connection data groups are not
directly referenced by the g2config data group 141, and are located
by virtue of the fact that they are located below the same entity
as the g2config data group 145, 146 for each application.
[0177] Each connection data group 146, 148 will include indications
of a protocol to be used, a port number of the source application
to which data should be sent, an identifier for the host on which
the source application is operating, a proxy identifier (if
appropriate), together with parameters related to session refresh
and logout.
[0178] In addition to the parameters described above, the
connection data group will include various other parameters
appropriate to the protocol being used.
[0179] If SOAP is being used these parameters will include a file
part of a URL to use for connection, a URI style for message
encoding, a URI for the target object, and a URI indicating the
intent of the SOAP request.
[0180] If JDBC is being used, these parameters will include a URL
for JDBC database connection, a JDBC driver name, and parameters
indicating both initial and maximum JDBC connection pool sizes.
[0181] Other protocols will require other parameters, and such
parameters will be readily apparent to those of ordinary skill in
the art.
[0182] In addition to the data set out above, various other
configuration data may be used to configure the CL service of the
AA. Such configuration data may either be stored in one of the data
groups described above, or alternatively may be stored in an
additional data group. Typically, such additional data groups are
located within the same source application entity 143, 144 as the
data groups described above, and accordingly the instance entity
136 is able to locate all necessary configuration data.
[0183] The CL service 119 of the CA node 106 (FIG. 14) is
configured in a similar manner, although it will be appreciated
that in this case, data of a similar form will be required for the
or each composite application instead of the source applications.
In some embodiments of the IDM, the data group 141 includes an
entry for each composite application in addition to entries for
each source application, and these entries in turn identify
appropriate entities located below the EXT_APPS entity 140.
[0184] Configuration data for the DT service 120 of the CA node
106, and for the DT service 124 of the AA node 107 is now
described. FIG. 22 is a tree diagram showing part of the hierarchy
of FIG. 20, together with details of entities pertinent to
configuration of the DT services.
[0185] The service entity 135 has a child entity 149
BASE_DT_SERVICE which in turn has a child entity DT_SERVICE 150
which represents all DT service configuration data. An entity
LAB1_DT 151 is a child entity of DT_SERVICE and represents DT
service configuration for the application represented by the
LAB1_INS entity 136.
[0186] It can be seen that the host.process1.AA.DT and
host.process1.CA.DT entries in the data group 137 both reference a
DT.service data group 152 which is located beneath the Lab1_DT
entity 151. The DT.service datagroup contains a single entry which
allows it to locate its parent entity.
[0187] A DT.Applications data group 153 is located under the same
entity 151 as the DT.service data group 152. The DT.Applications
data group 153 contains one entry for each composite application
which must be handled by the DT service of the CA, and one entry
for each source application which must be handled by the DT service
of the AA. In the example of FIG. 22, it can be seen that the data
group 153 includes an entry for a single composite application
Lab1App, and a single source application firstbyte. FIG. 22 shows
data needed to configure the DT service of the CA to handle the
composite application Lab1App.
[0188] It can be seen that the Lab1App entry in the DT.Applications
data group 153 references a DT.AppLab1App data group 154 which
contains data relevant to handling transformations to and from the
composite application Lab1App. The DT.App.Lab1App data group 154
includes an entry indicating transformations required in response
to an IncomingUserRequest, an entry indicating transformations
required in response to an OutgoingUserRequest, and en entry
indicating transformations required to convert data from the UXM in
a form suitable for output to the composite application.
[0189] The UXM entry references a DT.App.Lab1App.UXM data group 155
which in turn contains entries which indicate how data should be
transferred between UXM objects used in the UXM of the CA, and data
which can be processed by the composite application. In the example
of FIG. 22, the data group 155 includes a NewObjectTransformations
entry which references a data group 156 and a UIElementTempates
which references a data group 157. This data allows new data to be
added to data received from source applications to create a
composite page. The UIElementTemplates data group 157 contains
details of such new data, and the NewObjectTransformations data
group indicates how this data should be included in a composite
page.
[0190] It can be seen that the other entries in the DT.App.Lab1App
data group reference other data groups 158, 159, 160 which contain
data indicating how these transformations should be carried
out.
[0191] FIG. 23 shows part of the IDM data structure which holds
data pertinent to the DT service of the AA node. It can be seen
that the firstbyte entry in the DT.Applications data group 153
references a DT.App.firstbyte data group 161, which includes an
entry for each data type which the DT service of the AA may be
required to handle, that is IncomingUserRequest,
OutgoingUserRequest, IncomingUserResponse, OutgoingUserResponse,
and UXM objects. It should be noted that although in the example of
FIG. 15 only OutgoingUserRequest and IncomingUserResponse messages
are processed by the DT service of the AA. However,
IncomingUserRequest and OutgoingUserResponse messages are included
for the case where the composer simply passes messages between a
composite application and a source application without carrying out
any processing.
[0192] It can be seen that the entries in the DT.App.firstbyte
datagroup 161 relating to the four message types reference
appropriate data groups 162, 163, 164, which contain the necessary
transformation information. The UXM entry references a
DT.App.firstbyte.UXM data group 165, which includes four entries.
An ErrorPageResolverData entry references a
DT.App.firstbyte.UXM.ErrorPageResoverData data group 166 which
contains means to recognise various error pages which may be
generated by the firstbyte source application. A PageResolverData
entry references a DT.App.firstbyte.UXM.PageResolverData data group
167 which contains data indicating how pages of the source
applications are recognised, in order to identify necessary
transformations. A PageExtractionConfig entry references a
DT.App.firstbyte.UXM.PageExtractionConfig data group 168 which
contains references to a plurality of Extensible Markup Language
(XML) files, which indicate how each page recogniser by an entry in
the PageResolverData data group should be transformed by the DT
service before being passed to the UXM service of the AA.
[0193] Configuration data for configuring the UXM service 121 of
the CA node 106 is now described with reference to FIG. 24, which
shows the relevant parts of the IDM data structure. The highest
level of the illustrated tree structure is a BASE_UXM_SERVICE
entity 169 which is a child of the SERVICE entity 135 (FIGS. 20 to
23). The BASE_UXM_SERVICE entity 169 has three child entities, a
CA_UXM_SERVICE 170 which represents data relevant to the UXM
service 121 of the CA node 106 (FIG. 14), A UXMActionLibrary entity
171 which stores UXM action data, and a UXMPredicateLibrary entity
172 which stores predicate data.
[0194] The CA_UX_M_SERVICE entity 170 has a child entity named
TreeRootNode for each composite application which the UXM is able
to handle, and an additional entity 173 to deal with error
conditions. A TreeRootNode entity 174 represents a first composite
application CompApp1, while a second TreeRootNode entity 175
represents a second composite application. Each TreeRootNode entity
173, 174, 175 has a control data group which specifies a unique
identifier. In the case of the data group 176 associated with the
entity 173, this identifier is simply "error", while in the case of
the data groups 177, 178 an appropriate identifier is set. The
control data groups additional include information which can be
used to limit a particular nodes usage. Under the TreeRootNode 174
which relates to CompApp1, there are two child TreeNodes which each
represent different pages of the composite user interface for
CompApp1. A first child TreeNode 178 and its associated data group
represent a page customer page CustPg, while a second child
TreeNode 179 and its associated data group represent an order page
OrderPg. It can be seen that the TreeNode 178 in turn has three
child TreeNode entities 180, 181, 182, each of which represent
particular parts of the customer page.
[0195] It was indicated above that the identifier within the
control data group for each composite application must be unique.
It should be noted that within a particular application, all
identifiers must be unique within that application.
[0196] FIG. 25 shows an alternative view of the tree structure of
FIG. 24. It can be seen that in addition to the control data groups
described above, All TreeRootNode entities 174, 178, 180, 181, 182
additionally include an integration data group 183 which specifies
the actions to be taken, if any, when a composite application of
the type represented by the TreeRootNode 174 is encountered. This
information is determined by data stored in a library located under
the UXMActionLibrary entity 171.
[0197] Additionally, the TreeRootNode entities 178, 180 comprise a
predicates data group which specifies conditions (or predicates)
which need to be true for the actions specified in the integration
data group to be taken. Each of these predicate data groups
references a predicate library located under the
UXMPredicateLibrary entity 172.
[0198] FIG. 26 shows part of the UXM configuration for a composite
application Lab2App represented by a TreeRootNode entity 183. It
can be seen that the TreeRootNode entity 183 has a control data
group 184 and an integration data group 185. A TreeNode 186
specifies UXM data for part of the Lab2App application, and has a
control data group 187 and an integration data group 188. The
integration data group specifies actions to be taken in response to
particular events, and these actions are specified in terms of an
appropriate data group. For example, an entry for an action
deleteUXMObj.1 references a DeleteUXMObjectFromTagetConext.RemData
data group 189 within an action library Lab2_Lib 190 for the
Lab2App application. Similarly an aggregateNews.2 entry in the
integration data group 188 references an
AggregateNamedContexts.AggregateNews data group 191 in the Lab2_Lib
library 190. In turn, this data group references two TreeNodes 192,
193 which are child entities of the TreeNode entity 186. The other
entries in the integration data group 188 reference corresponding
entities 194, 195 in the Lab2_Lib library 190. Operation of the UXM
in accordance with the configuration data described above is set
out in further detail below.
[0199] Configuration of the ML services of the CA node 106 and the
AA node 107 (FIG. 14) is now described. As indicated above,
communication between processes is accomplished using JMS, and the
JMS protocol is encapsulated within the ML services. Referring back
to FIG. 20 it can be seen that ML entries of the g2config data
group 137 reference an appropriate g2config data group 196, located
beneath an ML_SERVICE 197 which is itself located beneath a
BASE_ML_SERVICE entity 198. For the most part, configuration of the
ML is based upon properties files, not by data within the IDM.
These files can be located using invocation parameters, as
described above with reference to FIGS. 16 and 17. The ML is
configured using properties files instead of IDM data because much
of the configuration is required at start up, before the IDM has
been accessed. In preferred embodiments of the invention, a common
configuration is shared by the CA node 106 and the AA node 107. JMS
makes use of the Java Naming and Directory Interface (JNDI) to
obtain necessary information. The properties files must therefore
contain details which allow connection to the JNDI. Additionally,
the properties file must include parameters which specify all
necessary configuration data for the JMS implementation used to put
embodiments of the invention into effect. In preferred embodiments
of the present invention, the SunONE MQ3.0 JMS implementation or
the OpenJMS 0.7.2 implementation are used Configuration data
required will be well known to those skilled in the art, and is not
described in further detail here.
[0200] However, it should be noted that some configuration
parameters used in preferred embodiments of the present invention
provide beneficial results. For example, it should be noted that
each process within the system can send broadcast messages using a
broadcast topic. Each process will have a single in queue and a
broker will manage these queues ensuring that any message is sent
to the in queues of all relevant processes. Additionally, each
process has a persistence queue, into which messages are delivered
if the in queue is unable to accept messages for any reason. This
queue provides failover for the system.
[0201] Having described configuration of all services of the CA
node 106 and the AA node 107 (FIG. 14), configuration of the ALF
service 126 of the ALF node 108 is now described. ALF configuration
data is stored in the hierarchical IDM data structure, as
illustrated in FIG. 27. The g2config data group 137 for the entity
Lab1_INS 136 references a g2config data group 199 located beneath
the BASE_ALF_CONFIG entity 131. The g2config data group 199
provides the information necessary to allow the ALF database 110
(FIG. 14) to be located. It can be seen that this data group
includes details of a url for the database, a driver to be used
with the database (here the Oracle.TM. JDBC driver) and user name
for use when logging onto the database 110. It will be appreciated
that other data may be required in order to properly access the
database 110 and this too will be stored in the g2config data group
199.
[0202] Each user who is authorised to use a composite application
will have a user entity 200, 201 which is a child of the
BASE_ALF_CONFIG entity 131. The user entity 200 has a G2 data group
202 which includes a user name used by that user when logging on to
composite applications provided by the composer. Additionally, the
user entity 200 has a SrcApp data group 203 which includes details
which are needed to log on to a source application "SrcApp". A
similar data group is provided for each source application which a
user is able to access. The user entity 301 has a G2 data group
204, and will also comprise one or more entries for appropriate
source applications (not shown).
[0203] The BASE_ALF_CONFIG entity 131 also has a usersconfig data
group 205 which specifies details relating to logging onto to the
composite application, for example password format, and a frequency
with which passwords must be changed. The values specified in the
usersconfig data group 205 provide a default log on configuration,
which is inherited by all user entities. However, this default
configuration may be overridden by a usersconfig data group located
below an appropriate user entity. It should be noted that similar
information relating to each source application is stored as part
of the configuration of the CL service within the AA node.
[0204] The BASE_ALF_CONFIG entity 131 has an additional child
entity CONSOLE_CONFIG 206. This entity comprises a plurality of
data groups (not shown) which state how configuration data input to
the system via the administration terminal 112 (FIG. 14) is
converted to ALF commands. Commands are typically received from the
web browser based administration terminal 112 as HTTP requests,
which are mapped to appropriate ALF commands. The administration
terminal 112 is used to add users and perform other necessary
administration functions related to the ALF.
[0205] Referring back to FIG. 20, it can be seen that the
host.process1.ALFNODE entry in the g2config data group 137
references a g2config data group 206 located beneath
BASE_ALF_ML_NODE 207. The host.process1.ALFNODE.ALF entry in the
g2config data group 137 references a g2config data group 208
located beneath a BASE_ALF_SERVICE entity 209. The g2config data
group 208 will allow access to the ALF database identified by the
g2config data group 199 located beneath the BASE_ALF_CONFIG entity
131.
[0206] Having described configuration of all services contained
within the nodes of the server 13, configuration of the listener
provided by the web server 12 is now described. As indicated above,
a g2listener invocation parameter specifies an entity within the
IDM which is used for listener configuration. FIG. 28 shows an
appropriate IDM data structure. In this case, the g2listener
parameter is set such that:
g2listener=weblistener;
[0207] That is, the listener would locate a weblistener data group
210 located beneath a UAconfigs entity 211. The weblistener data
group 210 indicates to where incoming requests should be directed
(usually a CA service), and the name of a Java class providing
authentication functions (in this case custom). The
weblistener.custom data group 212 provides a mapping from request
parameters to those needed for authentication.
[0208] It will be appreciated that means must be provided such that
appropriate configuration data can be entered into the IDM
database, to create the hierarchies described above. Specification
of this configuration data is now described using a predetermined
file format.
[0209] FIG. 29 shows a file which can be used to configure the CL
service 119 of the CA node 106. Text shown in square brackets "[ ]"
denotes an entity names within the IDM hierarchy. Text shown in
triangular brackets "< >" denotes a name of a data group
which is positioned beneath the appropriate entity within the IDM
hierarchy. Text shown in curly brackets "{ }" denotes a parameter
type. "{GRF}" indicates that a parameter is a reference to another
data group. A {GRF} parameter is followed by an appropriate entity
name and data group name to which it refers. "{STR}" indicates a
string parameter. Parameters specified by "{INT}" and "{BLN}" can
also be used, although these are not shown in FIG. 29. "{INT}"
indicates an integer parameter, and {BLN} indicates a Boolean
parameter.
[0210] Referring to FIG. 29, it can be seen that the file specifies
a CONFIG entity, having a SERVICE entity as a child, which in turn
has a BASE_CL_SERVICE entity has a child. A CA_CL_SERVICE entity is
a child of the BASE_CL_SERVICE entity, and has a LAB1_SrcApps
entity as a child. The LAB1_SrcApps entity has a single g2config
data group which comprises a single group reference entry which
references a g2config data group located beneath a FirstByte entity
within the hierarchical data structure.
[0211] The file of FIG. 29 also specifies that the BASE_CL_SERVICE
also has an EXT_APPS entity as a child entity, which in turn has a
FirstByte entity as a child. The FirstByte entity has a single
g2config data group which specifies two parameters of type string
which provide authorization and protocol information relevant to
the FirstByte application.
[0212] Having described configuration of the architecture shown in
FIG. 14, operation of services illustrated in FIG. 14 is now
described.
[0213] The UXM service 121 is responsible for receiving user
requests, and generating one or more source application requests in
response to the user request. The UXM service 121 is also
responsible for creating composite pages.
[0214] It should be noted that the UXM uses an internal data format
of UXMObjects to represent composite user interfaces and parts of
such composite user interfaces. Using UXMObjects in this way allows
the UXM service to operate in a manner independent of output
format, and accordingly adds considerable flexibility to the
system.
[0215] A UXMObject stores unstructured data, as well as attributes
describing that data. A tree of UXMObjects is used to represent
data for a composite user interface. It can be recalled that the
structure of the composite application is described by UXM
configuration data within the IDM database (see FIGS. 24 and 25).
The tree of UXM objects will typically correspond to the tree
structure for the UXM within the DDM, although it is important to
note that the two trees are separate data structures which are
stored separately.
[0216] A UXM object includes unstructured data for a particular
entity within the UXM tree of the IDM database, which represents
part of a composite user interface. This data is typically stored
using an array of bytes. Each UXMObject also has a mode parameter
and a type parameter. The mode parameter is used to indicate where
within a composite document a UXMObject should be placed relative
to other UXMObjects. The mode parameter can therefore take values
such as before, after, replace, insert and toplevel. The type
parameter is used to differentiate UXMObjects created by the UXM
service from UXMObjects created from source application data.
UXMObjects can therefore have types of New and Existing. Each
object additionally includes a set of attributes which are
associated with the unstructured data, and which either describe
the data, or are used for data conversion. Each UXM object has a
identifier (which can conveniently correspond to an ID within the
UXM tree within the IDM, see FIG. 24), and references to parent
and/or child objects if appropriate. These references to parent
and/or child objects allow the UXMObjects to be used to create a
UXM object tree. It should be noted that UXMObjects may also
contain nested UXMObjects.
[0217] During operation, the UXM maintains a UXM tree (separate
from the UXM object tree) which is based upon the configuration
data stored in the IDM. This tree includes the actions, predicates
and parameters which are present within the relevant entities and
data groups of the IDM. Additionally, each entity within the UXM
tree includes a state for each user at that node, which corresponds
to a user's context.
[0218] The context for a user at a particular entity within the UXM
tree will hold a state appropriate for that user for all requests
which that user may make and all response which that user may
receive. This is stored as a set of parameters (typically as NVPs),
and by reference to a single object within the UXMObject tree.
[0219] In summary, it can be seen that the UXM essentially uses
three data structures, the IDM data structure, the UXM tree and the
UXMObject tree.
[0220] Information indicating how the UXM should operate in
response to various requests and responses is configured within the
IDM tree which at runtime is used to create the UXM tree. In
addition to this information, the UXM tree also stored information
relating to state of a particular user at a particular node is
stored at a user's context at a particular entity within the UXM
tree. Data pertaining to particular pages of the composite user
interface is stored within a UXM object, and UXM objects
collectively form a UXM object tree, which is separate from both
the UXM tree and the IDM data structure. It can be deduced that for
every entry in the UXM object tree, there must exist an entity in
the UXM tree having the same identifier. The converse is not
necessarily true.
[0221] FIG. 30 shows a schematic illustration of part of a UXM tree
220 and a UXMObject tree 221. It can be seen that each entity in
the UXM tree 220 includes context information for User 1 The
context data associated with each entity in the UXM tree 220
includes reference (denoted by a broken line) to an appropriate
instance of a UXMObject in the UXMObject tree 221. It can be seen
that the UXM tree 220 and the UXM Object tree 221 have the same
structure. It will be appreciated that in many embodiments of the
present invention respective context data will be stored for a
plurality of users, and each of the plurality of users will have a
respective UXM object tree.
[0222] When describing the IDM data structure, it was explained
that actions were executed if predicates were satisfied. Predicates
which may appear in predicate data groups within the IDM are now
described.
[0223] Some predicates are based on a user's log on credentials.
Users may be allocated to one of a plurality of roles, and a
RoleAuthorisedGuardCondition predicate entry specifying a
particular role may be included in a predicate data group. This
predicate will be satisfied only if a user's role matches the
specified role. Similarly a RoleNotAurthorisedGuardCondition is
satisfied only if a user's role does not match that specified by
the predicate.
[0224] Some predicates are based on a NVP within a user's context
at a given entity within the UXM tree. A
CompareNVPValueGuardCondition predicate compares a specified NVP at
a specified entity within the UXM tree with a specified NVP at a
different entity within the UXM tree. The predicate has a parameter
indicating whether it should should evaluate to TRUE for equality
or inequality.
[0225] A RegexNVPMatchGuardCondition predicate takes a regular
expression as a parameter, and evaluates to true if a specified NVP
at a specified entity within the UXM tree matches the regular
expression.
[0226] An NVPEqualsGuardCondition predicate checks a value of a
specified. NVP in a user's context at the current entity against a
value specified as a parameter, and evaluates to TRUE in the case
of equality. An NVPNotEqualsGuardCondition predicate performs the
opposite function to an NVPEqualsGuardCondition predicate--that is
it evaluates to TRUE in the case of inequality.
[0227] An NVPExists predicate checks if a specified NVP exists
within the user's context at the current entity within the UXM
tree. If the NVP does exist, the predicate evaluates to TRUE. An
NVPNotFound fulfils the opposite function to an NVPExists
predicate, that is, it evaluates to TRUE if a specified NVP does
not exist at the current node.
[0228] Various other predicates can also be specified. A
RemoteServiceCredentialFound-GuardCondition predicate determines
whether a user's context at a specified entity within the UXM tree
includes log on credentials for a specified external system (e.g. a
source application). If the service credential exists, the
predicate evaluates to TRUE. A
RemoteServiceCredentialNotFoundGuardCondition predicate performs
the opposite function, that is it evaluates to TRUE if a user's
context at a specified node does not include a service credential
for the specified external system.
[0229] ExternalIDs are used by the UXM to identify data elements
within external applications, such as source applications. Some
actions provided by the UXM are concerned with creating and using
ExternalIDs. The UXM maintains mappings between ExternalIDs, and
internal IDs used within the IDM.
[0230] An ExternalIDFoundGuardCondition predicate evaluates to TRUE
if a user's context at a specified node includes a specified
ExternalID. An ExternalIDNotFoundGuard-Condition predicate
evaluates to TRUE if the specified ExternalID is not found. A
NodeGuardCondition takes a plurality of entity ID's as a parameter,
and evaluates to TRUE if the ID of a specified entity matches one
of the plurality of specified IDs.
[0231] A DataReady predicate checks if data (usually an UXMObject)
is present at a specified entity within the UXM tree. This
predicate is used to ensure that data necessary for aggregation
(see below) is present at a given entity within the UXM tree.
[0232] A FalseGuardCondition predicate, and a TrueGuardCondition
predicate may also be specified. A FalseGuardCondition always
evaluates to FALSE effectively ensuring that the associated actions
are never executed. A TrueGuardCondition always evaluates to TRUE
ensuring that the associated actions are always executed.
[0233] A first task performed by the UXM service 121 is to generate
requests to source applications following receipt of a request for
a user. Operation of the UXM in performing this task is now
described.
[0234] When a UserRequest message is received by the UXM service
121 (usually from the DT service 120), a UXM_MODIFIED parameter
within the message is checked. If this is set to FALSE, the message
is directed to a source application without processing by the UXM.
It this is set to TRUE processing is carried out as follows and a
UserRequest event is generated.
[0235] The UserRequest event causes the UXM to locate within the
IDM the entity specified by the UXM_NODE_ID parameter. This entity
then becomes a user's active aggregation point. In this case that
node is the TreeNode 178. Any predicates specified in a predicate
data group associated with that node are then checked. Assuming
that all predicates are satisfied, the actions referenced by the
entries of the integration data group (as defined by their
respective data groups) are then carried out. The UXM traverses
down through the UXM tree evaluating predicates and executing
actions associated with each entity, each entity encountered
typically providing a list of actions, one or more of which may
reference an appropriate source application. Details of actions
which may appear in an integration data group are set out
below.
[0236] Actions are in general associated with a single event type.
However, it is possible to override this associated by using an
EVENTMASK parameter is an action's data group. This parameter is an
N-bit binary value and is set such that each bit represents a
different event, and that the action is associated with all events
for which the respective bit is set to `1`--four example if four
actions are used to trigger actions, the EVENTMASK parameter should
be a four-bit binary value.
[0237] Actions typically associated with a UserRequest event are
now described.
[0238] A UserRequestAction is by default associated with a
UserRequest event, but may be associated with other events by using
the EVENTMASK parameter in the manner described above. This action
generates a new source application request which is targeted to the
APPLICATION_CLASS of the source application. A request will be a
made to each source application which is required to produce the
composite page.
[0239] The entries in an UserRequestAction data group specify
information relevant to creating a request(s) for sending to
particular source application(s), however it should be noted that
details relating to connection to that application are not
included, as these are specified by the CL service 123 of AA node
107. Each source application request will include only information
specified by the relevant action data group, and will not
necessarily include parameters present in the IncomingUserRequest
message.
[0240] A source application request will include an
APPLICATION_CLASS parameter which specifies an application class
name for the source application, and an APPLICATION_PATH parameter,
which specifies a path for locating the application. Additionally,
a source application request may include a request method
indicating how data should be requested. This parameter may take a
value such as HTTP_GET in the case of a HTTP request. The message
additionally includes a string comprising zero or more parameters
which are picked up from the current context. If this parameter is
the empty string, then no values are added to the source
request.
[0241] A DeflectUXMRequest action is again associated with a
UserRequest event by default, although this association can be
overridden using an EVENTMASK parameter as described above. A
DeflectUXM action generates a source application request of the
type described above, but here the parameters for that request are
obtained from the IncomingUserRequest message, not from the current
context. This action is usually triggered to re-use an original
user request message, and the UXM merely decomposes the message
into parts relating to different pages of the source
application.
[0242] A UXMRequestLink action is associated with a UserRequest
event, and cannot be overridden by using the EVENTMASK parameter in
the manner described above. This action triggers a UserRequest
event on an entity within the UXM tree identified by a TARGETNODE
parameter. The receiving entity will then respond to the
UserRequest event as specified by its UXM entries. This action
effectively adds an aggregation point to the UXM Tree.
[0243] A JumpToTreeNode action is again associated with a
UserRequest event, but can be overridden using the EVENTMASK
parameter. This action jumps to a different branch of the UXM tree
structure, and causes a UserRequest event on an appropriate entity.
This differs from the UXMRequestLink action described above in that
the current aggregation point is removed, and replaced with the
specified target aggregation point.
[0244] A number of actions are concerned with manipulating values
(typically name, value pairs (NVPs)) within the current UXM
context. A CopyNVPAction action is associated with a UserRequest
event, but can be overridden using the EVENTMASK parameter as
described above. A CopyNVPAction action copies sets an NVP at a
specified target node to a value obtained from a specified source
entity. The action includes identifiers of both the source and
target entities, and details of the source NVP and target NVP
within those entities. If a target NVP is not specified, as a
default, it is assumed that the target NVP is the same as the
source NVP. Optionally, a prefix and/or suffix may be specified
which is prepended or appended to the source NVP when it is copied
to the target NVP.
[0245] A ConcatenateNVPAction action is again associated with a
UserRequest event but can be overridden by the EVENTMASK parameter.
This action concatenates a plurality of NVPs at a source entity and
copies these to a specified NVP at a target entity. The action
takes as parameters a source entity identifier (which defaults to
the current entity if not specified), a target entity identifier, a
comma separated list of names from NVPs which are to be
concatenated, and the name of an NVP to be created at the target
entity. The value assigned to the created NVP will be the
concatenation of the values from the NVPs in the comma separated
name list.
[0246] An AddSequenceListener action is associated with a
UserRequest event but can be overridden using the EVENTMASK
parameter if necessary. This action sets the context of the current
entity as a sequence listener of an entity specified by a
TARGETNODEID parameter.
[0247] A StoreRemoteServiceCredential action is associated with a
UserRequest event but can be overridden using the EVENTMASK
parameter if necessary. This action allows information about a
remote service (e.g. a source application) to be stored as a
parameter in the context of the current entity. The information is
stored as a NVP, and is typically security information related to a
source application. The action includes a REMOTE SERVICE parameter
which is an identifier for a remote service (e.g. a source
application), and a CRED_TYPE parameter which is used to indicate
the type of credential being stored. The CRED_TYPE parameter can be
set to USRPWD or IDONLY. If CRED_TYPE is set to USRPWD, the NVP
stores both a username and a password. If it is set to IDONLY, only
a username is stored. The name of the NVP is of the form
"credential.<remote_service>.username|password", where
<remote_service> is an identifier obtained from the REMOTE
SERVICE parameter.
[0248] Having generated one or more source application requests in
response to UserRequestAction actions and/or DeflectUXMRequest
actions (in addition to carrying out any other actions which may be
necessary), the created source application requests are used to
create OutgoingUserRequest messages which are then usually targeted
to a DT service 124 of an AA node.
[0249] A second function of the UXM is to compose responses
received from source applications to form the composite
application. The UXM service of the CA node generally receives
source application responses from the DT service 124 of the AA node
107. An outline of the actions carried out by the DT service 124 of
the AA node 107 is now presented, to aid understanding of the
operation of the UXM.
[0250] The DT service 124 of the AA node 107 recognises pages
returned by source applications using predefined rules. The
recognition process is described in further detail below, but it
should be noted that the DT attempts to recognise normal pages
first, then error pages. Assuming that the page is recognised a UXM
object tree representing that page is generated.
[0251] Referring to FIG. 31, there is illustrated a simple example
conversion which may be carried out by the DT service 124 to
generate an appropriate UXM object tree. A HTML document 222
comprises a table 223, which in turn comprises a form 224 and an
image 225. The DT service generates a UXM object tree 226 from this
HTML document. The UXM object tree 226 comprises four UXM objects,
one for each element of the HTML document 222. It can be seen that
these UXM objects are hierarchically arranged such that a . . .
Body object 227 is at the root of the tree, a . . . Body.Table1
object 228 is a child of the . . . Body object, and a . . .
Body.Table1.Form object1 229 and a . . . Body.Table1.Image1 object
230 are children of the . . . Body.Table1 object 228. Thus, the
hierarchy of the UXM object tree 226 mirrors that the of the HTML
document 222. It should be noted that each entry in the UXM object
tree 226 is prefixed by " . . . " to indicate that in practical
embodiments of the invention, the names of entries are prefixed by
an appropriate source application name. Operation of the DT service
124 is described in further detail below.
[0252] Having created the plurality of UXM objects, these are sent
to the UXM service 121 of the CA node 106.
[0253] A message is received by the UXM from the CA service of the
AA node 107. If the message comprises one or more UXM objects, a
UserResponse event is generated by the UXM. UXM objects may be
nested within a received message, and in such a case the UXM
unnests the received UXM objects to create individual UXM objects
as appropriate. The created individual UXM objects are then copied
to the user's context at the appropriate entity of the UXM tree
structure and form the UXMObject tree. The appropriate entity can
be identified using the ID parameter of the received UXMObject
which, as described above, will correspond to the ID of an entity
within the UXM tree.
[0254] The UserResponse event causes the UXM to traverse the UXM
tree beginning at the entity specified by the ID parameter of the
received UXMObject. For each entity within the tree which is
processed in this way, the UXM determines if all predicates
(specified in appropriate predicate data groups) are satisfied for
each entity. If the predicates are satisfied for a given entity,
the actions associated with that entity (as specified in an actions
data group) are executed. Details of actions which are generally
associated with UserResponse events are now described.
[0255] A RegexTransformNVPValue action is by default associated
with a UserResponse event, although this association can be
overridden using the EVENTMASK parameter as described above. This
action sets a NVP within the user's context, for a target entity
within the UXM tree. The action specifies a SOURCENODEID parameter
which defaults to the current entity if not specified, an a
mandatory SOURCENAME parameter which specifies an NVP within the
source entity. The action may optionally specify TARGETNODEID
parameter identifying a target entity and a TARGETNAME parameter
identifying a NVP within the target entity. If these are not
specified, the TARGETNODEID is set to be equal to the SOURCENODEID
and/or the TARGETNAME is set to the equal to the SOURCENAME. The
action also includes a REGEX parameter which specifies a regular
expression which is applied to the source NVP to generate the
target NVP.
[0256] Regular expressions will be well known to those skilled in
the art as a way of manipulating strings within computer programs.
In the case of some embodiments of the present invention regular
expressions of the type used in the Perl5 programming language are
preferably used, although it will be readily apparent to those
skilled in the art that regular expressions of different formats
can also be used in embodiments of the present invention.
[0257] A CopyUXMObjetValueToTargetContext is again associated with
a UserResponse event, but can again be overridden using the
EVENTMASK parameter as described above. This actions sets an NVP in
a user's context at target entity within the UXM tree. The value to
which the NVP is set is taken from a UXM object at a source entity.
The action takes SOURCENODEID and TARGETNODEID parameters which
respectively specify source and target entities within the UXM
tree. If these parameters are not set, by default the current
entity is used. The action has a mandatory TARGETNAME parameters
which specifies an NVP within the target node which is to be
set.
[0258] A SetUXMObjectProperties action is again associated with a
UserResponse event, but can be overridden as described above. The
action specifies a plurality of NVPs which are set within the UXM
object at the current entity of the UXM tree.
[0259] A SetTargetUXMNode action is associated with a UserResponse
event, but can be overridden using the EVENTMASK parameter. This
action sets attributes of a UXMObject at an entity specified by an
ACTIONTARGET parameter, which defaults to the current entity if no
value is specified. The UXM object specified by the ACTIONTARGET
parameter is updated so that it points to a UXMTreeNode relating to
a different entity within the UXM object tree specified by a
mandatory TARGETNODE parameter.
[0260] A CopyUXMObjectToTargetContext action is again associated
with a UserResponse event but can be overridden. This actions sets
the UXMObject at an entity specified by a SOURCENODEID parameter to
point to the UXMObjects specified by an entity given in a
TARGETNODEID parameter. The SOURCENODEID parameter is optional, and
defaults to the current entity if not specified.
[0261] A RelocateUXMObject action is associated with a UserResponse
event and cannot be overridden using the EVENTMASK parameter. This
action sets the mode parameter within a UXM object associated with
an entity specified by a TARGENODEID to "Relocate", and results in
the object being relocated (i.e. moved rather than copied) to a new
parent.
[0262] A DeleteUXMObjectFromTargetContext action is again
associated with a UserResponse event but can be overridden. This
action deletes the UXM object associated with the entity specified
by a mandatory TARGETNODEID parameter.
[0263] A ConditionalCopyOfUXMChildObjectToTargetContext action is
associated with a UserResponse event but can be overridden. This
action compares a value of an NVP specified by a SOURCENVPNAME
within the context of the current entity with the same NVP in an
entity referenced by a CHILDNODETOCOMPARE parameter. If the
comparison is such that a predetermined condition is satisfied, a
UXM object identified by a CHILDNODETOCOPY parameter is copied to
the context of an entity identified by a TARGETNODEID parameter. It
should be noted that the parameters CHILDNODETOCOMPARE and
CHILDNODETOCOPY are specified relative to the current entity, and
not as absolute path names.
[0264] A CopyUXMObjectValue action is again associated with a
UserResponse event and cannot be overridden using the EVENTMASK
parameter. This action copies values from a UXM object present at
an entity identified by a SOURCENODEID parameter to a UXM object
present at an entity identified by a TARGETNODEID parameter.
[0265] A CopyUXMObjectValueFromTargetContext is again associated
with a UserResponse event but can be overridden. This action will
copy a value of an NVP identified by a SOURCENVPNAME parameter in
the context of an entity identified by a SOURCENODEID to a UXM
object at an entity identified by a TARGETNODEID parameter.
[0266] A RegexTransformUXMObjectValue is by default associated with
a UserResponse event but this can be overridden using the EVENTMASK
parameter. This action retrieves a UXM object from an entity
identified by a SOURCENODEID parameter, applies a regular
expression specified by a REGEX parameter and writes the resulting
value to an entity identified by a TARGETNODEID parameter.
[0267] A UXMObjectNotification action is associated with a
UserResponse event and cannot be overridden. It takes no
parameters. It copies a UXMObject from a current context to the
child of an active aggregation point having the same name. For
example, if the action is associated with an entity having a path
S1.A1.A2 and the active context is S1.C1, the id of the current
entity (i.e. A2) is used to locate an entity within the active
context which should refer to the UXM object. In this case, that is
S1.C1.A2.
[0268] Those actions which relate to manipulation of Externals and
which are by default associated within a UserResponse action are
now described.
[0269] A LoadExternalID action can have its association overridden
using the EVENTMASK parameter described above. This action
retrieves an ExternalID which is specified by an
EXTERNALENTITYCLASS parameter and an APPLICATION_CLASS parameter
from the current context, and writes this value to a UXM object
associated with the current context.
[0270] A StoreExternalID action can again have its association
overridden by use of the EVENTMASK parameter. This action saves the
value of the UXM object associated with the current entity as an
ExternalId having an application class identified by an
EXTERNALENTITYCLASS parameter.
[0271] A ClearExternalIDs actions can be overridden, and clears all
external ID's from the context of an entity identified by a
SOURCENODEID parameter.
[0272] Having traversed the tree, and executed all actions for
which predicates are satisfied, execution returns to the user's
active aggregation point (i.e. the entity within the UXM tree which
received a UserRequest event to trigger the source application
requests which in turn generated the response from the AA). Each
node of the UXM tree beneath the node which received the
UserRequest event is interrogated to ascertain whether or not it
has received its UXM object. When all entities beneath the entity
which received the request have received their objects, a
UXMAggregate event is created to cause aggregation.
[0273] It should be noted that in preferred embodiments of the
present invention, each node in the UXM tree can specify that a UXM
object is mandatory or optional within its control data group using
a Boolean isMandatory variable, which defaults to FALSE where not
specified. In such embodiments, a UXMAggregate event is created as
soon as all mandatory UXMObjects are present. However, in
alternative embodiments of the invention it may be desired to await
all mandatory UXM objects, then apply a predetermined time out,
after which aggregation is carried out using those objects which
have been received.
[0274] A UXMAggregate event causes the UXM to traverse all entities
which are children of the current entity, and execute all actions
specified in the integration data group which are triggered by a
UXMAggregate event. Some actions which are associated with
UXMAggregate events are now described.
[0275] An AddUXMObjectAction action is by default associated with a
UXMAggregate event, but this can be overridden using the EVENTMASK
parameter described above. This action creates a new UXMObject and
adds this to an entity identified by a TARGETNODEID parameter. This
action therefore allows UXMObjects to be created at any point in
the UXM tree. An OBJECTID parameter specifies a name for the new
UXMObject, and OBJECTTYPE and MODE parameters specify the created
object's type and mode as described above. A RELATIVETO parameter
allows the TARGETNODEID to be specified relative to a an entity
specified by the RELATIVETO parameter, although if RELATIVETO is
not specified, it defaults to the top level.
[0276] As described above, the AddUXMObjectAction action creates a
new UXM object at a target entity. An INSIDETARGET parameter allows
configuration of what should happen if a UXM object already exists
at the target entity. If the parameter is not specified, and the
UXM object already at the target entity is of type "container" the
current object is provided as a child of the existing UXM object at
the target entity. If the INSIDETARGET parameter is set to TRUE,
the new UXMObject is set as a child of the existing UXM object. If
the INSIDETARGET parameter is set to FALSE, the existing UXM object
becomes a child of the new UXM object at the target entity.
[0277] A CreateUXMObject action is by default associated with a
UXMAggregate event, but this can be overridden using the EVENTMASK
parameter as described above. This action creates a new UXMObject
and adds it to the user's context at the targeted entity. It should
be noted that everything which can be achieved using a
CreateUXMObject action can be created by an AddUXMObjectAction
which has appropriate parameters. That is the CreateUXMObject
action can be thought of as an AddUXMObjectAction with some
hard-coded parameter values.
[0278] An AggregateChildObjects action is by default associated
with a UXMAggregate event. This cannot be overridden using the
EVENTMASK parameter described above. This action is essential to
creating composite user interfaces. It aggregates all UXMObjects at
contexts of entities which are children of a target entity, and
creates a new UXMObject at the targeted context. Any UXMObjects
which have a mode set to delete are ignored for the purposes of
this action, all others are inserted as nexted UXMObjects. A
parameter for the action specifies the target entity.
[0279] An AggregateNamedContexts action is by default associated
with a UXMAggregate event, but this can be overridden using the
EVENTMASK parameter described above. This action allows zero or
more entities to be specified, and the UXMObjects associated with
each of those entities are aggregated to form a new UXMObject at an
entity specified by a TARGETNODEID parameter.
[0280] A DeleteUXMObjectAction action is by default associated with
a UXMAggregate event, but this can be overridden using the
EVENTMASK parameter described above. This action will set any
UXMObjects present at an entity defined by a TARGETNODEID parameter
to have a Mode of Delete, meaning that it will not be included in
aggregation actions (see above). It should be noted that this
action does not delete objects, but simply sets their mode
parameter to have a value delete.
[0281] An AddHTMLElementAction action is by default associated with
a UXMAggregate event, but this can be overridden using the
EVENTMASK parameter described above. This action is used to inset a
HTML element into a UXMObject in the context of an entity
identified by a TARGETNODEID parameter. In order for this action to
work, the UXMObject must have a type parameter as specified by an
ENLTMERATED_HTML_ELEMENT_TYPE parameter within the
AddHTMLElementAction action. Possible values for the
ENUMERATED_HTML_ELEMENT_TYPE parameter are html_radiobuttongroup,
html_checkboxgroup and html_dropdownlist. An AddHTMLElementAction
also takes parameters which specify a name, a value and text for
the HTML element. For each type of HTML element further parameters
relevant to that element may be specified by the
AddHTMLElementAction.
[0282] If a UXMObject at a target context has a type of
html_radiobuttongroup, an AddHTMLRadioButton action is by default
associated with a UXMAggregate event, but this can be overridden
using the EVENTMASK parameter described above. This action adds a
radio button to the radio button group represented by the
UXMObject.
[0283] Having executed all actions appropriate to a UXMAggregate
event, the entity within the UXM tree which received the user's
request has a UXMObject which represents the requested composite
page, which can be passed to the DT service 120 of the CA node
106.
[0284] It should be noted that UXMObjects are passed between
services by creating an XML representation which is then used as a
payload of a message to be transferred between services. This is
achieved using a toXML method provided by a UXMObject.
[0285] It should be noted that the UXM comprises further
functionality in addition to that which is described above. Actions
triggered by various events have been described above. It should be
noted that some actions may by default be associated with no
particular event, and in such cases the EVENTMASK parameter must be
used to determine association.
[0286] The UXM service 121 allows JavaScript scripts to be
associated with given entities within the tree, and these scripts
can be executed by inclusion in an action data group, in the manner
described above. The JavaScript is interpreted by the UXM at run
time, and executed to perform the necessary functions. It will be
appreciated that scripts may need to communicate with the UXM to
obtain relevant data. This is achieved by providing a UXMRUNTIME
object which can be accessed by scripts.
[0287] Methods exposed by a Java object can be invoked directly
from a script, assuming only that the script has the Java object's
identifier. The methods exposed by a UXMRUNTIME object allow
scripts to be effectively created.
[0288] A UXMRUNTIME object allows various operations to be carried
out on UXM objects specified by a path within the UXM tree. This
path is a string comprising the name of an entity prepended by a
`.` prepended by the name of its parent entity, which in turn is
prepended by a `.` and its parent entity name. For example the
string "MyTRN.page1.FormElement" denotes an entity "FormElement"
which has as its parent an entity "page1" which is a child of a
TreeRootNode entity "MyTRN". It should be noted that fully
specified paths must always be used within UXM scripts. This is
because a UXM script is not considered to be executed from a
particular entity within the UXM tree, and accordingly a relative
path will have no well defined meaning.
[0289] Methods provided by the UXMRUNTIME object are now
described.
[0290] A prepareUXMObject method takes a path of the form described
above as a parameter and allows the UXMObject specified by the path
to be accessed by the script. The thread in which the script is
executing is blocked until the UXMObject is returned, and the
UXMObject's availability can therefore be assumed. This method will
effectively trigger a UserRequest event on the node specified by
the path parameter, and it is therefore important to ensure that
nodes which are to be used in this way by scripts are provided with
actions triggered by UserRequest events. An entity targeted by this
method is typically a source page, and this method effectively
creates a request to fetch the source page, which is subsequently
provided to the script. If the UXMObject cannot be provided to the
script for any reason, an error field within the UXMRUNTIME object
will contain details of any exception which was thrown. The error
field of the UXMRUNTIME object should therefore be checked (see
below) before attempting to the use the requested UXMObject. A
prepareUXMObjects method functions analogously to prepareUXMObject,
but takes an array of paths as its parameter, and returns all
requested UXMObjects.
[0291] A getUXMObject method retrieves a UXMObject from an entity
specified by a path parameter. A setUXMObject method sets a UXM
object at a specified entity to a UXMObject provided by a parameter
of the method.
[0292] The UXMRUNTIME object provides various methods for accessing
and manipulating NVPs at a given entity within the UXM tree. A
setNVP method allows a specified NVP to be set to a specified value
at a specified entity within the UXM tree. A getNVP method allows
the value of a specified NVP to be obtained from a specified
entity. A clearNVPs method allows all NVPs to be cleared from a
specified entity. A getRequestParameter returns the value of a
request parameter at a specified entity in the UXM tree.
[0293] It was mentioned above that the UXMRUNTIME object includes a
field in which details of any errors are stored. A hasException
method returns a value indicating whether or not an exception
occurred during processing, and a getException method returns
details of any exception that occurred.
[0294] Error details may also be stored within a user's context at
an entity of the UXM tree. Various methods are provided to access
such error details A getErrorDetail method gets details of such an
error message from an entity specified by a path parameter. A
requestHadError method returns a value indicating whether or not an
error occurred. A getErrorLodation returns the name of a service
(e.g. UXM, DT, CL) at which the error occurred.
[0295] A getErrorMessage method returns details of the error
message generated, and getMajorErrorCode and getMinorErrorID
methods return details of error codes. All these methods take a
path specifying an entity within the UXM tree as a parameter.
[0296] In general terms, scripts can be used to replace the
mechanisms described above for carrying out aggregation. When a
script is used an integration data group will typically contain a
single entry referencing an action data group for the script within
an action library which contains a script name and details of the
script.
[0297] If a script is used for aggregation, it will be appreciated
that it is important to ensure that a mechanism is provided such
that the script knows when all necessary source pages have been
received by the UXM as UXMObjects. This is provided by a
ScriptResponseNotification action, which is provided in an action
library, and included in the integration data group of each source
page, and which is triggered after processing of a UserRequest
event.
[0298] The runtime memory space of the script will include details
of all requested source pages. When a UXMObject corresponding to a
source page is received by the UXM the UXMRUNTIME object is updated
by the ScriptResponseNotification. The UXMRUNTIME object in
response to the ScriptResponseNotification then updates the runtime
memory space of the script.
[0299] It should be noted that when scripts are used, two
parameters which may be specified in the control data group
associated with an entity are of some importance. An EVENTORDER
parameter controls the order in which child entities are processed.
A HANDLEERROR parameter needs to be set to TRUE, so as to allow the
script to process any errors that may occur during execution,
instead of the global error handling generally provided by the
composer.
[0300] The scripting functions described above are provided by the
Bean Scripting Framework (BSF) which is provided by the Java
programming language. This framework allows a number of different
scripting languages to be used, although as described above,
JavaScript is used in preferred embodiments of the present
invention. It should be noted that on first execution the
JavaScript script will be complied to generate Java Byte Code which
can be interpreted by a Java Virtual Machine. It will therefore be
appreciated that a script will take longer to execute on its first
execution.
[0301] Operation of the DT service is now described. The DT service
includes a plurality of transformation engines which may be applied
to data to cause data transformations. The transformation engines
are stateless, and a single instance of each engine exists within a
particular DT service. These transformation engines are now
described in further detail.
[0302] An APICallExtemalizer translates data from internal
representations to external representations using ExternalIDs
described above and such data can then be used by the CL service to
generate API calls. A DOMtoString transformation engine converts a
DOM object representing an HTML file (typically received from a
source application) into a string.
[0303] An IDExternaliser transformation engine and an
IDInternalizer transformation engine respectively convert internal
IDs to external IDs and external IDs to internal IDs.
[0304] The DT service includes some transformation engines to
process and correct HTML provided to it. A HTML TagBalancer tag
balances incoming HTML to produce well formed HTML as output. A
HTMLTidy transformation engine makes use of Jtidy to correct
malformed HTML, and ensures that the output is XHTML compliant.
[0305] A JavaSpecializedEngineExecutor transformation engine
executes specialized transformations that are hardcoded into a Java
class. The Java class specified for this engine must implement a
predefined JavaEngine interface specifying a single execute( )
method which is used to transform data, so that it can be known
that the Java class will include this method which is required for
transformation.
[0306] A Marshaller transformation engine makes use of the Castor
framework to convert Java objects into XML, as described at
http://castor.exolab.org. This engine can be used for generic
transformations.
[0307] A PageResolver transformation engine recognizes response
pages and applies appropriate extraction configuration. It first
tries to recognize normal pages, then error pages and finally
applies a default extraction if no match is found.
[0308] A RegEx transformation engine takes a string input, applies
a regular expression to it and returns a string as output.
[0309] A RegexAggregator transformation engine is used to insert
new user interface elements into a user interface. The
configuration of this engine is a single regular expression string.
Some regular expressions have special meanings, and will be
substituted before the regular expression is applied: [0310]
_VALUE_ is replaced by the value of the OBJECT_ID parameter in the
engine definition data-group. [0311] _NAME_ is replaced by the
value of the NAME parameter in the engine definition
data-group.
[0312] A RegexExtractor transformation engine is used to extract
user interface elements in UXM format using regular expressions. It
also marks up the input string where the string fragment was
extracted.
[0313] A UIAggregator transformation engine is used to aggregate
the UXM user interface data into a form suitable to return to the
user. It is typically only used in the CA.DT. A UIExtractor
transformation engine converts the incoming response page into UXM
Objects which can be forwarded to the UXM service. This is used in
the AA.DT.
[0314] An Unmarshaller transformation engine makes use of the
Castor framework to convert XML into Java. A UxmObjectDecomposer
transformation engine is used in the process of aggregating UXM
user interface data. It decomposes complex UXM objects into simpler
ones so that the aggregation can take place in later stages. A
UxmObjectToString extracts the data from a UXMObject and returns it
as a string.
[0315] An XMLParser transformation engine takes a string as input
and parses it into a DOM tree. The resulting XML tree is the output
of the engine. An XpathExtractor transformation engine is used to
extract user interface elements in UXM format using XPath. It also
marks up the input string where the string fragment was extracted.
It is used primarily in the UXM. An XSLTransformer transformation
engine takes an XML document as input, applies a XSL style sheet to
it and returns an XML document as output.
[0316] The transformation engines outlined above provide a variety
of basic functions which are required by a DT service. The
transformation engines are used by transformation actors which act
on the data to transform it. There are essentially two types of
transformation actors: atomic actors make use of transformation
engines directly, while group actors use other transformation
actors.
[0317] An atomic actor holds configuration data indicating how a
transformation engine should be used to carry out the necessary
transformation. For example, an atomic actor using an XSL
transformation engine may be configured using an XSL style sheet.
The output will then be a DOM object (see above). When called, the
actor will pass the input data and the configuration data to the
transformation engine to cause the transformation to be
effected.
[0318] An atomic actor has a type parameter which is set to "base"
which indicates that the transformation actor is an atomic actor.
It has a textual description of the transformations which it
carries out. It has a EngineID parameter which identifiers one of
the transformation engines set out above which is to be used by the
actor. A configuration parameter is represented by a string. This
will typically be a regular expression or alternatively a file name
of an XSL style sheet. Some actors will have multiple outputs,
while other actors will always have a single output value. This is
represented by a MultipleOutputs parameter which is set to TRUE if
multiple outputs are allowed, or FALSE if MultipleOutputs are not
allowed. If an actor for which MultipleOutputs is set to FALSE
produces multiple output data at run time, the data is merged using
a Java class specified by a DataMerger parameter. A Timeout
parameter provides a timeout, preferably in milliseconds.
[0319] A group actor combines one or more other transformation
actors. The transformation actors being grouped may be atomic
actors or group actors, and can be executed either in parallel or
sequentially, or as alternatives.
[0320] A group actor has a type parameter which is set to "group",
a description parameter specifying a textual description, and a
parameter TransformationIDs which is a list of actors contained
within the group actor. A GroupType parameter can take values of
"sequence", "parallel" and "switch". If the GroupType parameter is
set to "sequence" all the contained transformation actors are
executed sequentially, in the order in which they are listed in a
Transformation IDs parameter. If the GroupType parameter is set to
"parallel", all the contained transformation actors are executed in
parallel. If the GroupType parameter is set to switch, a single
actor will be chosen at run time to act upon the passed input data.
A LateInitialization parameter takes a Boolean value indicating
whether or not late initialisation should be used. That is, this
parameter indicates whether the transformation engine should be
initialised at start up (if LateInitialization is set to FALSE), or
when the transformation engine is used for the first time (if
LateInitialization is set to TRUE). A group actor also has
MultipleOutputs, DataMerger and Timeout parameters, as described
above with reference to atomic actors.
[0321] In preferred embodiments of the present invention some
atomic actors and some group actors are provided by default.
Details of these transformation actors are now described.
[0322] Atomic actors provided by default are as follows. A NOP
actor performs no operation, which can be necessary in the DT in
cases where no transformation is required. Three further atomic
actors simply make transformation engines described above available
as actors. A HTMLTagBalancer actor makes the HTMLTagBalancer
transformation engine available as an actor, a UXMObjectDecomposer
actor is used by the DT service of the CA and makes the
UXMObjectDecomposer transformation engine available as an actor. A
UXMObjectToString actor makes the UXMObjectToString transformation
engine available as an actor, and an XMLParser actor makes the
XMLParser transformation engine available as an actor.
[0323] A PageResolver actor is used by the DT service of the AA to
recognise pages returned by source applications. It picks up
details of the pages to be recoginsed from the appropriate parts of
the IDM, as described above. A UIExtractor actor is used by the DT
service of the AA to convert pages into UXMObjects, again
appropriate configuration information is provided by the IDM.
[0324] A UIAggregator actor is used by the DT service of the CA to
convert UXM objects into a form suitable for returning to a user as
part of a composite application. A URLRewrite actor is used to
update any necessary URLs, forms and/or frames in a page which is
to be returned to a user.
[0325] A plurality of group actors are also provided by default. A
sequence.IncomingUserResponse actor is a sequence of transformation
actors which can be applied to a typical incoming user response
message, to convert the page response into UXM form. It applies the
PageResolver actor and the UIExtractor actor described above.
[0326] A sequence.OutgoingUserResponse actor is sequence of
transformation actors to apply to a typical outgoing user response
message to convert the UXM Object tree into the resulting page to
return to the user. It applies an actor to convert a marshalled
UXMObject tree into a XML tree and then aggregates the various
components according to information in the XML tree. The result is
converted to a string representing the page which is returned to
the user.
[0327] A sequence.UIAggregation actor comprises a sequence of
transformation actors to apply to aggregate the components of a
page into the final page. It applies other transformation actors to
decomposes and aggregate and then uses the atomic actor
UIAggregator described above.
[0328] A sequence.UIAggregation.DecomposeAndAggregate is a sequence
of transformation actors which are applied to get the page elements
ready for aggregation. It first decomposes the top most UXMObject
using the UXMObjectDecomposer actor. It then recursively goes down
through the tree repeating the same action.
[0329] A switchgroup.UIAggregationRecursion is a switch group of
transformation actors. It goes down through the UXMObject
hierarchy, choosing at each stage whether the UXMObject contains
other UXMObjects or not.
[0330] A sequence.UIExtraction actor comprises a sequence of
transformation actors which are applied to extract the components
of a page into a UXMObject tree. It decomposes and aggregates, then
uses the atomic actor UIAggregator
[0331] A switchgroup.UIExtractionRecursion actor is a switch group
of transformation actors. It goes down through the UXMObject
hierarchy, choosing at each stage whether the UXMObject contains
other UXMObjects or not.
[0332] Operation of the DT service within the AA node for a
particular source application is illustrated in FIG. 32. Data is
received from a source application is denoted by an arrow 231. This
data is first passed to a transformation engine 232 which makes any
necessary amendments to URL references included in the received
source data. This can be achieved using, for example, the RegEx
transformation engine described above. A second transformation
engine 233 performs any generic URL amendments that may be
necessary, and can again be the RegEx transformation engine
described above. A HTML tag balancer transformation engine 234 (of
the type described above) is then used to ensure that the produced
HTML is well formed.
[0333] The output of the HTML tag balancer is input to a group
actor 235 which is configured to recognise and process the received
source page. The group actor 235 comprises a suitable PageResolver
transformation engine 236 which is configured to recognise
predefined pages, and a group actor 237 which comprises one or more
of the transformation engines described above, which together act
to extract user interface elements from recognised pages.
[0334] Having described configuration of the composer, and the key
services contained within its nodes, its operation in providing
composite applications, as outlined above with reference to FIG.
15, is now described in further detail, referring again to FIGS. 14
and 15.
[0335] Processing typically begins when a user using the web
browser 126 makes a HTTP request which is subsequently directed to
the web server 12. The servlet 117 operating on the web server 12
determines whether or not the URL entered relates to a page
provided by the composer. If it is determined that the URL does not
involve the composer, the web server obtains and displays the
requested web page in a conventional manner. If the URL is to be
provided by the composer, the servlet 117 intercepts and processes
the HTTP request. This involves converting the HTTP request into an
IncomingUserRequest JMS message.
[0336] It will be appreciated that some requests will require
authentication. Authentication is handled using cookies. When a
user first attempts to access a page requiring authentication the
request will be intercepted by the CL service of the CA node, and
this service will determine whether or not the request includes any
required cookie. If no such cookie is present in the request, the
user will be presented with a page into which suitable
authentication data (e.g. username and password) is entered. This
data is sent to the web server, and onwards to the ALF service 126
of the ALF node 108, where the input authentication data is checked
against data stored in the ALF database. Assuming that this
authentication process is successful, the user's original request
is processed. A cookie is stored on the user's computer, and in the
case of subsequent requests, this cookie is read by the web server,
forwarded to the CL service of the CA node, and then forwarded to
the ALF service 126 to enable authentication using the ALF database
110. The following description assumes that all necessary
authentication has been successfully carried out.
[0337] Creation of the JMS message is carried out as specified by
the appropriate configuration data within the IDM. Having created
an appropriate IncomingUserRequest message, and determined to where
it should be sent using the target parameter within the weblistener
data group 210 (FIG. 28) it is then necessary to locate an
appropriate instance of the target service which can accept the
created message.
[0338] The listener performs load balancing over JMS, so that a
plurality of instances of a target service can be used
concurrently, and requests can be effectively distributed between
the plurality of composers. The JMS properties file for the
listener (described above) includes a
resolverprotocol.roundrobin.target parameter which specifies a load
balancing algorithm which is to be used such as, for example the
round robin algorithm. This parameter will also specify how many
instances of the target (in this case the CL service of a CA) to
expect.
[0339] When an instance of the target service starts up, it
declares itself using an appropriate JMS message, and the listener
will then know that messages can be sent to that instance of the
target service. When a listener needs to send a message to an
instance of the target service (e.g. to the CL service of a CA) a
broadcast message is sent to all instances of the service
registered with the listener. The listener will then await a
response from all registered targets, any responses from
non-registered targets are simply ignored. When all expected
responses have been received, the listener chooses one instance of
the target service in accordance with the specified algorithm, and
the IncomingRequestMessage is sent to the selected instance.
[0340] Having selected a target to receive messages from a
particular user, the listener ensures that subsequent messages from
that user are directed to the same composer. This need not
necessarily be the case, and is determined by an add affinity
parameter within the IDM. Similarly, the IDM configuration for the
composer has an add listener affinity parameter which ensures that
messages for a particular user are always directed to the same
listener.
[0341] The transmitted IncomingUserRequest JMS message will be
received by the CL service 199 of the CA node 106 via its ML
service 118 which is responsible for JMS messaging. On receipt of
the IncomingUserRequest message, the CL may perform authentication
using log on parameters specified in the IncomingUserRequest
message, by using the ALF service of the ALF node in the manner
described above. Assuming that authentication is successful, the
message is simply passed to the DT service 120 of the CA node. The
passage of messages between services, is determined by data stored
within the message objects, as described above.
[0342] The DT service 120 retrieves configuration data pertinent to
the actions required in response to receipt of an
IncomingUserRequest message. The data is retrieved by accessing the
IDM data structure (FIG. 22), and locating the DT.Applications data
group 153. The data group 154 pertinent to the composite
application specified in the IncomingUserRequest message is then
located, and the action referred 158 referenced by the
InocmingUserRequest message in the data group 154 is then
identified and carried out. On receiving an IncomingUserRequest
message, no transformation is usually required, and the DT service
120 therefore performs no operation, as specified by the data group
158. The message is then passed to the UXM service 121 of the CA
node 106.
[0343] The IncomingUserRequest message is typically generated from
a HTTP request as described above. A suitable HTML fragment for
such a request is shown in FIG. 33. It can be seen that the third
line specifies that the composite application's application class
name is "CompApp1". The fourth line specifies that the request
requires modification by the UXM, the fifth line specifies a node
in the IDM tree structure relevant to the application, and the
sixth line specifies a node in the IDM relevant to the page which
generated the request. All this data is encapsulated within the
IncomingUserRequest message.
[0344] The UXM will locate a "CompApp1" node within the UXM tree,
and traverse down the tree structure, executing any actions for
which the predicates are satisfied. These actions will typically
involve creating one or more OutgoingUserRequest messages directed
to appropriate source applications, which are forwarded to the
source applications via the AA node 122, and these messages are
therefore forwarded to the AA node.
[0345] In the present example, an AA node is present within the
same process as the CA, and can therefore be located without
problems. However, if no such node exists within the current
process. The message(s) are forwarded to the ML service 118 of the
CA node 106 and the ML service then attempts to locate an
appropriate AA node within a different process using JMS, as
described above with reference to FIG. 12D. When a suitable node
has been located, the message(s) are forwarded to the ML service of
that node, and onwards to the CL service of that node. Using JMS in
this way allows convenient inter-process communication, regardless
of the distribution of processes between physical machines.
[0346] An OutgoingUserRequest message is received by the DT service
124 of the AA node 107. The DT service must transform the
OutgoingUserRequest into a form understandable by the target source
application. In many cases, there will be no action required by the
DT at this stage as shown in the example configuration of FIG. 23,
where it can be seen that the OutgoingUserRequest entry of the
DT.App.firstbyte data group 161 references a no operation action
162. The OutgoingUserRequest message is therefore forwarded to the
CL service 123 of the AA node 107.
[0347] The CL service 123 uses configuration data stored within the
IDM to locate a data group representing the correct source
application (e.g. the g2config data groups 145, 147 of FIG. 21).
This data group will specify any authentication information which
must be included in a request to that source application. In order
to obtain such authentication information the CL service 123
requests authentication data from the ALF service 126 of the
ALFNODE 108, and this data is then fetched from the ALF database as
indicated by data in the IDM.
[0348] As described above, the IDM configuration for a CL service
also specifies parameters which are used to connect to the
appropriate source application (specified in a connection data
group). The CL service will use these parameters to determine the
format of request which should be generated for onward transmission
to the source application. For example, this may be a HTTP request
directed to a particular port of a particular host. This request is
then transmitted to the source application.
[0349] The source application will process received request
messages in a conventional manner, and data output in response to
the request is in turn received by the CL service 123 of the AA
node 107.
[0350] The CL service 123 receives the data from the source
application, and forwards this data to the DT service 124 of the AA
node 107. At this stage the DT service 124 must act upon the
received data to transform it into a form suitable for sending to
the UXM service 121 of the CA node 106. This processing will be of
the type illustrated in FIG. 32 above.
[0351] The created UXMObjects are then forwarded to the UXM service
121 of the CA node 106. The UXM will record the received objects
within the UXM Tree as described above, and when all necessary data
has been received, aggregation will occur to create one or more
UXMObjects representing the requested composite page. The created
UXMObjects are then forwarded to the DT service 120 of the CA node
106, in one or more messages containing XML versions of the created
UXMObjects.
[0352] The DT service 120 of the CA node 106 must then receive the
messages, recreate the UXMObjects, and use data from the IDM
configuration to determine how to convert the received UXMObjects
into a form suitable for output to the user. Suitable forms may
include HTML, or plain text.
[0353] It should be noted that by using an internal form until the
composite page is processed by the DT service 120 of the CA node
106, the system described above can easily by adapted to handle
different output types, simply by adding appropriate configuration
data to the IDM for the DT service 120. This allows an effective
decoupling of the composer from the output format required. Similar
decoupling can be provided when handling input data.
[0354] The created output data is then forwarded by the DT service
120 to the CL service 119. The CL service uses the IDM data
structure to determine the protocol which should be used to return
the composite page to the user, usually via the servlet 117 of the
web server 12.
[0355] Referring back to FIG. 14, operation of the administration
terminal 112 which is connected to the service 13 by means of the
connection 113 is now described. It is preferred that the
administration terminal 112 is connected to the server by a network
connection, and a conventional Transmission Control
Protocol/Internet Protocol (TCP/IP) connection of the type used in
Internet networks can suitably be used. The administration terminal
may operate by running a web browser and accessing an adminconsole
HTML document which is provided on a suitable port number of the
server (e.g. port 8080).
[0356] When a user has logged onto the administration server, it is
possible to create users, and roles. Users are allocated to roles,
and the roles to which a user is allocate determine the actions
which may be performed by that user. Roles specify commands which
may be executed by their users and may also specify child nodes
which inherit their properties.
[0357] When roles have been created users can be allocated to
created roles. Users can be removed from roles as necessary, and
deleted if no longer required. If a role is deleted, data for all
users allocated to that role is automatically updated. The
administration terminal can also be used to set up a user's service
credentials, that is the security data needed by a user to access
various source applications used within the composite
applications.
[0358] Although the embodiment of the invention described herein is
implemented using the Java programming language it will be
appreciated that the invention is in no way restricted to a Java
implementation. Indeed, the invention can be implemented using any
appropriate high level computer programming language. However, it
is preferable to use an object oriented programming language to
obtain the benefits of reuse and encapsulation which are inherent
in such computer programming techniques.
[0359] Although the present invention has been described
hereinbefore with reference to particular embodiments, it will be
apparent to a skilled person in the art that modifications lie
within the spirit and scope of the present invention.
* * * * *
References