U.S. patent application number 11/432683 was filed with the patent office on 2007-01-18 for session bean implementation of a system, method and software for creating or maintaining distributed transparent persistence of complex data objects and their data relationships.
Invention is credited to Ward Mullins.
Application Number | 20070016595 11/432683 |
Document ID | / |
Family ID | 32961606 |
Filed Date | 2007-01-18 |
United States Patent
Application |
20070016595 |
Kind Code |
A1 |
Mullins; Ward |
January 18, 2007 |
Session bean implementation of a system, method and software for
creating or maintaining distributed transparent persistence of
complex data objects and their data relationships
Abstract
The invention provides systems, methods and software for
creating or maintaining distributed transparent persistence of
complex data objects and associated data stores. In one aspect, the
invention also relates to an application programming object capable
of creating or maintaining distributed transparent persistence of
data objects or data object graphs without the necessity of
inserting any byte codes or modification of the object graph.
Virtually any java object or object graph can be transparently
persisted. Further, copies of a data graph or of a portion of the
data graph can be automatically reconciled and changes persisted
without any persistence coding in the object model.
Inventors: |
Mullins; Ward; (San
Francisco, CA) |
Correspondence
Address: |
LEV INTELLECTUAL PROPERTY CONSULTING
4766 MICHIGAN BOULEVARD
YOUNGSTOWN
OH
44505
US
|
Family ID: |
32961606 |
Appl. No.: |
11/432683 |
Filed: |
May 11, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10386011 |
Mar 10, 2003 |
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11432683 |
May 11, 2006 |
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Current U.S.
Class: |
1/1 ;
707/999.1 |
Current CPC
Class: |
G06F 9/4493 20180201;
Y10S 707/99945 20130101 |
Class at
Publication: |
707/100 |
International
Class: |
G06F 7/00 20060101
G06F007/00 |
Claims
1. A system for creating or maintaining transparent persistence of
a member selected from the group consisting of a data object, an
object graph model and a portion of an object graph model when a
user of the system is creating, maintaining, accessing or
navigating complex data objects as a CDOG model, comprising: a) a
set of definitions for the relationships between a data source
schema and objects capable of sotring data for an object language
application, wherein the set of definitions is stored in a
repository; b) a set of definitions for the relationships between
objects for an object language application, c) an object name, a
list of objects, or a set of objects that are to be persisted, d)
an object or set of objects as a programming module that contains
logic capable of persisting an indicated object or set of objects,
e) an input method to inform the programming module of d) with the
location of information related to a), b) and c), and f) at least
one data source to which persisted data may be stored.
2. A system according to claim 1, that does not require any
modifications to an object model or the inclusion of any
persistence byte code in the object model in order to provide
persistence for all or a portion of the CDOG model.
3. A system according to claim 2, that provides persistence for a
CDOG model on a distributed network environment.
4. A system for creating or maintaining transparent persistence of
a member selected from the group consisting of a data object, an
object graph model and a portion of an object graph model when a
user of the system is creating, maintaining, accessing or
navigating complex data objects as a CDOG model, wherein d)
comprises a generic ejb stateful session bean.
5. A system according to claim 1, that does not require any
modifications to an object model or the inclusion of any
persistence byte code in the object model in order to provide
persistence for all or a portion of the CDOG model, wherein d)
comprises a generic ejb stateful session bean.
6. A system according to claim 2, that provides persistence for a
CDOG model on a distributed network environment, wherein d)
comprises a generic ejb stateful session bean.
7. A software module, or set of modules, for creating or
maintaining transparent persistence of a member selected from the
group consisting of a data object, an object graph model and a
portion of an object graph model when a user of the system is
creating, maintaining, accessing or navigating complex data objects
as a CDOG model, comprising: i) a software module for creating a
set of definitions for the relationships between a data source
schema and its stored data to objects in a object language
application, ii) a software module for creating set of definitions
for the relationships between objects in an object language
application, iii) a software module providing an input means for an
object name, a list of objects, or a set of objects that are to be
persisted, iv) a software module containing the programming logic
to persist an object or set of objects based upon access to (a) a
set of definitions for the relationships between a data source
schema and objects capable of storing data for an object language
application, (b) a set of definitions for the relationships between
objects for an object language application, and (c) an object name,
a list of objects, or a set of objects that are to be persisted,
and v) a software module having an input method to inform iv) of
the location of the information related to iv)(a), iv(b) and
iv(c).
8. A software module, or set of modules, according to claim 7, for
creating or maintaining transparent persistence of a member
selected from the group consisting of a data object, an object
graph model and a portion of an object graph model when a user of
the system is creating, maintaining, accessing or navigating
complex data objects as a CDOG model, comprising software code for
generating, accessing, or maintaining a generic ejb stateful
session bean object as part of the software module of iv).
9. A software module, or set of modules, according to claim 7, that
does not require any modifications to an object model or the
inclusion of any persistence byte code in the object model in order
to provide persistence for all or a portion of the CDOG model,
comprising software code for generating, accessing, or maintaining
a generic ejb stateful session bean object as iv).
10. A software module, or set of modules, according to claim 9,
that provides persistence for a CDOG model on a distributed network
environment.
11. A software module, or set of modules, according to claim 9,
that further comprises software logic providing to a user the
ability to query against the CDOG model or object graph using an
object query facility or syntax.
12. A method according to claim 11, wherein the object query
facility utilizes EJB-QL query syntax or similar syntax.
13. A method according to claim 12, wherein the object query
facility utilizes the EJB-QL query syntax.
14. A method according to claim 11, wherein the object query
facility utilizes a query syntax similar to a EJB-QL query syntax
and including expanded functions not provided by EJB-QL querying.
Description
CONTINUING APPLICATION
[0001] Based on: Utility application Ser. No. 10/386,011 filed
03-10-2003 which was based on Provisional Application No.
60/362,325 filed 03-07-2002
FIELD OF THE INVENTION
[0002] The field of the present invention relates generally to
computer systems, computer data stores and to methods and software
for accessing and utilizing data stores. More particularly, the
present invention relates to a system, methods and software for
creating or maintaining distributed transparent persistence of
complex data objects and associated data stores. In one aspect, the
invention also relates to an application programming object capable
of creating or maintaining distributed transparent persistence of
data objects or data object graphs without the necessity of
inserting any byte codes or modification of the object graph.
Virtually any java object or object praph can be transparently
persisted. Further, copies of a data graph or of a portion of the
data graph can be automatically reconciled and changes persisted
without any persistence coding in the object model.
BACKGROUND OF THE INVENTION
[0003] Systems for accessing data stores from object oriented
languages have been used for many years. A frequent approach to
accomplish access of data stores involves writing and embedding
custom access code within an object application needing the access.
This approach is generally limited to having the custom code access
only a single relational table within a relational database or
similar construct within any other data store (hereinafter
collectively "data store"). Under the circumstances where a
developer has control over the design and creation of a data store
from its inception, it is possible to design and store meaningful
information in a single table. Such design opportunities are
usually rare, however.
[0004] Generally, the methods for producing persistence for a data
object, complex data object or a data store conflict with the goals
of producing pure object application models where the object models
do not include persistence objects or persistence byte code.
Particular difficulties exist in a distributed environment since an
object application model may exist in one or more of a computer's
memory, an application data store and an application information
storage repository that may be independent of the data store
organization or object definitions. Advancements in the art have
been made with respect to tools for conveniently mapping objects to
systems of tables and maps in order to expedite accessing, changing
and updating data stores. See, for example, U.S. Pat. No. 5,857,197
(and its associated programming interfaces ("APIs")) describes
tools for translating object data to relational data, relational
data to object data, and object data to object data to expedite the
use of data stores. The BMP and the CMP Installer portions of
CocoAdmin tool in the CocoBase.TM. Enterprise for O/R Binary
Software (Thought, Inc. 657 Mission Street Suite 202, San
Francisco, Calif. 94105 http://www.thoughtinc.com,) provide means
for providing persistence in the EJB environment.
[0005] Persistence problems arise with the creation, access,
changing or deleting of an object application model that utilizes
such data stores. The object application model may be distributed
over multiple physical computer machine locations or even
distributed over multiple Internet website locations that may be
independent of the data stores. The object application model may
utilize a different set of data objects or different set of
definitions for relationships between data objects than that of one
or more of its data sources. In most situations, the respective
structures of the data sources and of the object applications model
simply do not conveniently allow for mapping, accessing or changing
of an overall schema of application data objects as well as any
associated definitions of relationships between two or more data
objects or elements within a data object.
[0006] Importantly, relationships may exist between a data object
and one or more of the other data objects found in the object
application model or in a data object of the data source. A
relationship between one data object and another data object or
with a data source may be member selected from the group of three
relationship types consisting of 1 to 1 (1-1), 1 to many (1-M) or
many to many (M-M). Complex combinations of these relationships may
exist as a data object relationships definition for a given data
object. These relationships are described or illustrated in further
detail later in this document.
[0007] Objects may logically span multiple relational tables or
multiple object databases, and may even be distributed over a
logical (or hypothetical) computer system involving multiple
physically independent computer systems or even multiple website
locations. Creating, accessing, maintaining or updating an object
application model can require working with multiple translation
modules and require tedious and repetitive updating of multiple
individual computer systems or multiple data sources in order to do
useful work and keep the object application model synchronized.
Such approaches are both costly and unwieldy in terms of computing
and development resources, particularly with respect to Internet
based electronic commerce (eCommerce) object application
models.
[0008] Data objects of an object application model are often a
feature of eCommerce object programming applications, where
information is obtained from a data source and the data is defined
as a data object (e.g., as a Java class) for use with another
computer application. In practice, a data object or model of data
objects may exist only in the random access memory of a computer
memory system, or may be saved to either a data source or to some
other type of retrievable information repository. A programmer or
administrator of an object data application cannot easily access or
track the overall model or diagram of data objects for an object
application model or some of its specific elements. Unfortunately,
tools for accessing and persisting data objects and associated data
object relationships of a complex data object graph model have not
been well implemented in the field of object language
programming.
[0009] A computer application can execute one or more of the
following non-limiting actions with respect to one or more of the
members selected from the group consisting of data, a data object,
and a data object definition: access data, change data, create
data, create a new relationship between one or more data objects by
creating or changing at least one data object relationship
definition, change or delete a relationship between one or more
data objects by changing or deleting at least one data object
relationship definition, access a data object relationship
definition and use its parameters to access a data source or a data
object, and access one or more data object relationship definitions
or data objects to create a new data object or data object
relationship. Any changes executed by a computer application with
respect to one or more of the members selected from the group
consisting of data, data object or data object definition may need
to be properly persisted (permanently stored) to preserve any
changes to one or more of the members selected from the group
consisting of data, a data object and a data object definition.
[0010] A data object and an associated data object relationship
definition may be represented by a complex data object graph
("CDOG"). A CDOG, for the purposes of this document, may be thought
of as a computer program data object graph that represents a data
object having at least one relationship with at least one other
data object or with itself via a circular link. When the data
object of a CDOG is implemented in the Java computer program
language, the CDOG may be further defined as being a Java Data
Object Graph ("JDOG").
[0011] There are needs for software, methods and systems that can
easily detect and persist any changes to at least one member
selected from the group consisting of a data object, any data
associated with the related object, or any associated CDOG
definition (i.e., an changes to the data object, data or to a
relationship of the data object with another data object). For
example, there is a need to be able access a pure object model
definition from a repository based O/R mapping tool or from a
modeling tool repository and provide persistence for the object
model without inserting any byte code or additional objects into
the object model.
[0012] Accordingly, there is a strong need in the art for a
computer applications programmer tool designed to assist a
programmer or administrator in the actions of providing persistence
for data objects or data object graphs when deleting, inactivating
or updating a CDOG, wherein the computer applications programmer
tool can be configured to automatically reconcile all or a portion
of a CDOG and copies thereof on a distributed environment when data
objects or relationships are inserted, deleted, inactivated or
updated for a CDOG. A particularly strong need exists for such a
tool having the further ability to be configured to persist,
propagate and reflect system wide (in a local or distributed
computer system) any such changes to a CDOG instance to all
instances of the CDOG and to all instances of associated data, data
objects and data object relationships.
Definitions
[0013] The following non-exhaustive list of definitions is used
herein to define terms that may otherwise be confusing or can
sometimes have multiple meanings. Each occurrence of a defined term
in the above text, in the text that follows, or in the claims of
this document, is to be given the meaning ascribed to it in the
list of definitions below.
[0014] "Instance" as referred to in this document in the context of
computer software applications is a single occurrence of a software
logical element in the memory of a computer system, such as a
"class", an "object", a "data object", and the like. This is
analogous to the occurrence of a logical memory unit representing a
row of data in common practice.
[0015] "Class" as referred to in this document in the context of
computer software applications is a logic unit in a computer
application or a computer software program where the application or
program is based upon an objected oriented programming language
(e.g., Java). In practice, a class is a logical unit used as a
logical template in an object oriented language from which to
allocate new instances of objects.
[0016] "Object" as used in the context of this document is a
general term referring to a logic unit in a computer application or
a computer software program where the application or program is
based upon an objected oriented programming language (e.g., Java).
The term "object" may ordinarily be used interchangeably with the
term "class" as a template or as an instance depending on the
context.
[0017] "Data object" as referred to in the context of this document
represents the concept of the occurrence of an object that holds
data within a specific computer application domain and is likely to
have its contents stored in a persistent data source of a computer
system (e.g., a database server, a binary file, a text file, or
even in a combination of two or more of such a persistent data
sources of a computer system). A data object may exist as an
independent data object without any relationship to any other data
object or it may have one or more relationships with itself or with
one or more other data objects.
[0018] "Complex data object" (or "CDO") as used in the context of
this document refers to the occurrence of a data object that has at
least one or more relationships with itself, or at least one or
more relationships with one or more other data object(s). In a
given instance of a CDO at least one relationship is populated as a
link, as defined below. A CDO may have a multiplicity of different
relationships with itself or with one or more additional CDOs.
[0019] "Relationship" or "data relationship" as used in the context
of a CDO refers to the type of logical combination that occurs
between a data object with itself, or refers to the type of logical
combination that occurs between a data object and at least one
another data object. Among other references or descriptions, such a
relationship is always referred to or partially described by a
"relationship type". This term is used in an object oriented
language context to reference or describe any expectations, actions
and limitations possible between two or more data objects.
[0020] "Relationship type" in the context of this document is a
label that specifies the possible multiple combinations that can
occur between a CDO and itself or with at least one other CDO. The
possible relationship type labels are 1-1 (one to one), 1-M (one to
many) and M-M (many to many). A given CDO may be simultaneously
related to more than one other CDO through several different types
of relationship. This is also sometimes referred to as the
multiplicity of the relationship.
[0021] "Link" as used in this document with respect to a CDO
identifies a particular occurrence of a relationship between a CDO
and itself, between a CDO and another CDO. The occurrence of at
least one populated link results in an instance of the CDO. This
may be considered a synonym for a "relationship" between two
objects.
[0022] "Circular link" as used in this document with respect to a
CDO identifies a particular occurrence of a relationship between a
CDO and itself that may be direct or indirect (e.g., linked to
itself through another CDO).
[0023] "Relationship definition" or "relationship description" in
the context of this document and computer software applications
refers to information, or an abstraction of information, regarding
a "relationship", "data relationship" "relationship type" or a
"link" that can be stored, accessed, transferred, communicated,
displayed or edited.
[0024] "Complex data object graph" or "CDOG" is a term employed
herein as an abstraction to logically represent a set of complex
data objects and a set of their corresponding relationships.
[0025] "Java data object graph" or "JDOG" is a term employed herein
as an abstraction to logically represent a set of complex data
objects and a set of their corresponding relationships that are
part of a Java programming application.
[0026] "Application model" or simply "model" are essentially
interchangeable terms employed herein as abstractions to logically
convey a collective description or other representation for a set
of complex data objects and a corresponding description or other
representation of their relationships. In one respect, these terms
are used logically herein provide a general way of efficiently
communicating when referring to set of metadata (i.e., data about
data) that describes possible data entities (e.g., objects,
database tables, maps, etc,) data relationship types, and data
constraints involved in a computer system or application, or in a
specific instance of an application. It is important to understand
the context in which the terms "application model" and "model" are
used in this document. Ordinarily computer engineers refer to the
"model" as an abstraction rather than a specific possibility or
instance of the model as applied. However, in this document for the
ease of communication abstractions of the model, possible
implementations of the model and instances of the model are all
referred to generally as "application model" or "model". From the
context of its use the term will be clear. The model is the
abstract relationship between classes, wherein the CEDO is an
instance (or set of instances) that express(es) the model.
[0027] "Navigation", "navigating" or "navigated" in the context of
the present document refers to an action implementing at least one
object to interact with a set of related objects for a certain
purpose, such as creation, access, insertion, modification and
deletion of an object, or of one of its relationships. It is the
physical act of traversing the relationships, which might be
referred to as "walking up or down the graph" in common lingo.
[0028] "Navigation model" as used herein is a special type of
application model that is applied specifically to a description (or
other representation) of how objects can relate to each other and
what might be the expected behavior when a CDOG is navigated for a
certain purpose.
[0029] "Object schema" is a term employed herein as an abstraction
referring to the set of data object classes that describe the
possible data objects that can be created, modified or maintained
in an application, or describing an instance of a set of data
object classes in an application.
[0030] "Distributed Transparent Persistence" is a term employed
herein as an abstraction referring to the concept of providing
persistence for a member selected from the group consisting of a
data object, a data object graph, associated data and data object
relationships in a distributed environment without the need for the
insertion of byte code or data objects in an object model or
schema.
[0031] "CocoBase Proxy Classes" is a term employed herein used in
referring to wrapper classes that provide CocoBase runtime
compatibility for objects that aren't inherently database aware. A
computer system can persist the attributes and data for any data
object that is wrapped with a CocoProxy wrapper class by simply
using CocoBase facilities. For example, source code for the
(attribute based) CocoProxy and (get/set method based) CocoProxyM
classes are available under the
thought\cocodemo3tier31\demos\pguide directory, when the CocoBase
software tools suite is installed on a computer system. This
optional design provides an extensible mechanism for instances of
data extraction and propagation.
[0032] "CocoBase Navigation API" is a term employed herein to refer
to an example of an API that provides database relationship mapping
and object graph management capability for persistent objects.
Database relationships are mapped to object links using CocoBase
Navigator link definitions. Persistence control is provided at each
class level in the object graph. Each of the Select, Insert, Update
and Delete operations are individually configurable.
[0033] "CocoBase Transaction API" is a term employed herein to
refer to an example of an API that provides object oriented
transaction support. Transaction objects are used to persist data
object attributes and maintain synchronization between database and
in memory attribute values. The Transaction API has many built in
optimizations, and applications utilizing CocoBase transactions
generally benefit from reduced database and network overhead. This
facility allows the developer to group together object changes into
a single unit of work whose implementation or storage will succeed
or fail all at once.
[0034] "CocoBase Factories" is a term employed herein to refer to
examples of software modules and softwares libraries that are used
to provide automated, custom object instantiation behavior. Factory
behavior is completely customizable. For example, a factory may be
used to bind newly instantiated objects to a transaction object, to
load a graph of related objects using the CocoBase Navigator, or to
implement polymorphism in a database result set. For example, a
ProxyFactory class is part of the current CocoBase software tools
suite distribution in the thought\cocodemo3tier31\demos\pguide
directory, and this factory returns result set objects wrapped in a
CocoProxy wrapper, when a CocoProxy wrapped key object is passed
into the CocoBase runtime software module as part of a query that
needs processing by the CocoBase runtime module.
[0035] "CocoBase Repository" is a term employed herein as an
abstraction referring to a datasource to dataobject mapping
repository and associated software modules that is installed into a
datasource (or may optionally be a single stand alone file or set
of files that circumscribe a set of datasource to dataobject
mapping definitions and associated software modules, or may be an
alternate data source). A repository can optionally be in a format
such as XML, XMI and the like. See, U.S. Pat. No. 5,857,197, the
CocoBaseEnterprise O/R Tools Suite, and the co-pending patent
appliction entitled "Dynamic Object-Driven Database Manipulation
and Mapping System" for more detailed descriptions of mapping
repositories, and the like.
[0036] "CocoBase Transparent Persistence for Objects and Object
Models". All models using a relational database for map storage
require the CocoBase repository to be installed into the database,
or in a stand-alone source accessable to CocoBase. The installation
of a mapping repository can occur automatically, if required, when
using CocoAdmin to log into the database. Pre-existing database
tables can be used, provided that the CocoBase repository is first
installed into the database, or accessible to CocoBase from an
alternate location. Several example of applications that implement
CocoBase transparent persistence are included in the CocoBase
software tools suite distribution (see the distribution
documentation for the location of folders or directories containing
such examples).
SUMMARY OF THE INVENTION
[0037] An object of the present invention is to provide a system
for creating or maintaining transparent persistence of a complex
data object, a complex data object graph (CDOG) model, or a portion
of a CDOG. In a preferred embodiment, an object of the present
invention is to provide such a system that can selectively persist
all or a portion of a CDOG model when the model is a member
selected from the group consisting of an object model generated
from a data object mapping repository and an object model generated
from data object modeling tool repository. A further object is to
provide such a system is located on, or is part of, a local or
distributed computer system.
[0038] An object of the present invention is to provide a method
for creating, maintaining, accessing, navigating and persisting
complex data objects stores in a repository. In a preferred
embodiment, an object of the present invention is to provide such a
method having the step utilizing the storage facilities of an
enterprise EJB server to store and maintain the data object graph.
In a further object, such a method involves a local or distributed
computer system.
[0039] An object of the present invention is to provide a computer
software component that operates in an EJB environment, or the
like, wherein the component has the capacity to access an object
model repository or an instance thereof in a computer memory or in
another temporary computer storage store device and persist at
least one action selected from the group consisting of creating,
maintaining, accessing, navigating, updating or deleting complex
data objects as a CDOG model. In a preferred aspect, the computer
software component is an Enterprise Bean selected from the group
consisting of Stateless, Stateful and Entity Beans. In a further
preferred object the computer software component is an EJB Session
Bean built on top of CocoBase runtime libraries having the ability
to persist all or a portion of a CDOG model or instance thereof. An
even more preferred object is to provide such a computer software
component capable of transparently persisting all or a portion of a
CDOG model or instance thereof for a local or distributed computer
system and automatically reconciling and persisting any changes to
an instance of the CDOG model or any changes to the repository
definition for the CDOG model.
[0040] A preferred object of the present invention is to provide a
software tool comprising a navigation API and software component
(as described above), adapted for a local network or a distributed
network environment, wherein said software tool provides
persistence in an object oriented language environment
transparently by implementing a configurable network component
capable of acquiring and persisting CDOGs through network APIs.
[0041] A further object of the present invention is a software tool
capable of reading a source programming object logic model or a
database in a format selected from the group consisting of a UML
data file a XMI data file, and a XML file and converting the
information into a target member selected from the group consisting
of a database definition XML file, a database mapping definition
file, and a CDOG definition file. In a preferred object, the
software can automatically generate a transparent persistence layer
that corresponds to the object model information of the source
file.
[0042] A further object of the present invention is to provide a
software module and source code known as a an Java entity bean
(such as a generic session bean) that is capable of providing
persistence of either or both of a data objects and a data model,
in total or in part as determined through setting established by a
user of the computer system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] For the non-limiting purpose of illustrating some of the
concepts of complex data objects CDOs, i.e., data objects and their
relationships to one another, according to the invention, two CDO
graph drawings FIG. 1 and FIG. 2 are provided.
[0044] FIG. 1 is a complex data object (CDO) graph drawing, which
illustrates a customer object and some of its related objects
(billing address, orders and items ordered), as well as
relationships between the objects. Relationships of the types 1 to
1 (1-1) and 1 to many (1-M) are shown in this CDO graph. More
specifically, FIG. 1 illustrates a CDO graph drawing presenting an
instance of a customer object 1 having a 1 to 1 (1-1) relationship
(5) with its customer billing address object 10, and a 1 to many
relationship (collectively 15, 25, and 35) with the three
outstanding order objects 20, 30 and 40, respectively. Order object
20 is an instance of an outstanding order object having a 1 to many
relationship (collectively 45 and 55) with the two items ordered
objects 50 and 60, respectively. Order object 30 is an instance of
an outstanding order object having a relationship with a single
order item, but order object 30 has a 1 to many relationship (65)
with the item ordered object 70, since many order items could have
been associated. Order object 40 is an instance illustrates a 1 to
many relationship (collectively 75 and 85) with the two items
ordered objects 80 and 90, respectively.
[0045] FIG. 2 is a complex data object (CDO) graph drawing, which
illustrates a company object and some of its related objects
(corporate address object and some of its departments and
employees), as well as relationships between the objects.
Relationships of all three types: 1 to 1 (1-1), 1 to many (1-M) and
many to many (M-M) are shown in this CDO graph. More specifically,
FIG. 2 illustrates a CDO graph drawing presenting an instance of a
company object 100 having a 1 to 1 relationship (650) with its
corporate address object 700, and a 1 to many relationship
(collectively 150, 250, and 350) with the three company department
objects 200, 300 and 400, respectively. Since employees of this
company may work for more than one of the company's departments,
the company department objects 200, 300 and 400 in FIG. 2 are three
instances (many) of company department objects having relationships
(425, 450, 550 and 575, respectively) with two (many) employee
objects (respectively, 500 and 600). The cross-assignment of
employee object 500 to both company department objects 200 and 300,
and of employee object 600 to both company department objects 300
and 400, illustrate a complex many to many (M-M) relationship of
departments to employees for this company.
DESCRIPTION THE INVENTION
[0046] The present invention provides a system for creating or
maintaining persistence for all or a part of a complex data object
graph model when a user is creating, maintaining, accessing and
navigating complex data objects as a complex data object graph
model. In one embodiment, the system comprises a computer system
having a user interface, a working memory storage area and at least
one device for permanently storing information, and said system
being loaded with at least one portion of a computer software
program, wherein said software program comprises at least one user
access interface and a set of programming routines designed for
creating or maintaining transparent persistence when a user is
creating, maintaining, accessing and navigating complex data
objects as a CDOG model. In a preferred embodiment, the present
invention provides such a system that can persist any part or all
of a CDOG model instance, and to resolve and persist any changes to
the model or to the repository for the CDOG model. Most preferred
is such a system providing a point and click graphical user
interface.
[0047] The present invention provides a method for creating,
maintaining, accessing, navigating and persisting complex data
objects stores as a CDOG model and providing transparent
persistence in a distributed environment, comprising the steps of:
[0048] a) creating or accessing a CDOG representation definition or
accessing an instance of the CDOG, [0049] b) monitoring and
recording any changes to the CDOG or a portion thereof on a local
or distributed computer system, and [0050] c) persisting any
changes to the CDOG on a local or distributed computer system by
updating the CDOG or CDOG representation definition to reflect and
changes to any copies of the CDOG or CDOG representation
definition, and saving a copy of the updated CDOG representation
definition to a data source or to another type of information
repository.
[0051] In a preferred embodiment, the present invention provides
such a method wherein the information data is a data store managed
by an EJB Enterprise server. In a further preferred embodiment an
EJB Enterprise Java Bean is the software component having the
ability to access a CDOG repository file, an UML XMI file or an
instance of the at least one portion of the CDOG in a computer's
memory or on a distributed network and provide the transparent
persistence for the CDOG model.
[0052] The present invention provides a computer software program
having at least one user interface and having at least one feature
that provides for at least one action selected from the group
consisting of creating or maintaining transparent persistence when
a user of a CDOG model is creating, maintaining, accessing or
navigating a CDOG model. In a preferred aspect of the invention,
the present invention provides a software program, or an
association with a software program, having a feature for
displaying, printing or displaying and printing a representation of
the CDOG model as a graph, or as a set of tables representing a
CDOG model. In a further preferred embodiment, such a software
program has an editing interface for editing the CDOG model, or has
an editable input or source, such as a file, that can be modified
to implement changes to the complex data object CDOG model (or has
both an interface for editing and an editable input or source, such
as a file).
[0053] The present invention also provides an application
programming interface ("API"), as a preferred embodiment, wherein
the API can be accessed to create, maintain, access, navigate and
persisting complex data objects as a CDOG model. In one aspect the
API can be accessed by an independent computer software program, or
by a computer software program module that is part of a software
package including the API, to provide at least one action selected
from the group consisting of creating, maintaining, accessing,
navigating and persisting complex data objects as a CDOG model. In
a preferred aspect, the present invention provides such an API as
part of a software tool package that provides a method for
displaying or printing a representation of the CDOG model as a
graph or set of tables representing the CDOG model (or providing
methods for both displaying and printing a representation of the
CDOG model). In another preferred aspect, such a software tool
package that includes the API provides an editing interface for
editing the CDOG model, or has an editable input or source, such as
a file, that can be modified to implement changes to the CDOG model
(or provides both an editing interface and an editable input or
source, such as a file,).
[0054] A preferred embodiment of the present invention provides a
software tool comprising the API according (as described above),
adapted for a local network or a distributed network environment,
wherein said software tool provides persistence in an object
oriented language environment transparently by implementing a
configurable network component capable of acquiring and persisting
CDOGs through network APIs.
[0055] In another preferred embodiment, the CDOG API is the
CocoNavigator API (or the more automated CBFacade API) which
provides support for manipulating complex objects in conjunction
with the THOUGHT Inc. CocoBase Enterprise Object/Relational (O/R)
database (hereinafter "CocoBase") mapping tool (see U.S. Pat. No.
5,857,197 (incorporated herein in its entirety), for concepts upon
which the CocoBase mapping tool is based). An object is considered
to be complex when it has established or potential relationships
(i.e. links) to other objects. For instance, a Company object
instance may be linked to an instance of its corporate address and
instances of a Department object, which in turn may be linked to a
set of instances of Employee objects. An example of such an CDOG is
shown in FIG. 2, for example. The combination of these objects and
their links constitute a graph of objects (CDOG model) that can be
manipulated using the CocoNavigator API. Since the CocoNavigator
API (or the CBFacade) works in a Java Programming language
environment, this CDOG example may also be referred to as a JDOG
example.
[0056] In one embodiment, the invention provides a system for
creating or maintaining transparent persistence of a member
selected from the group consisting of a data object, an object
graph model and a portion of an object graph model when a user of
the system is creating, maintaining, accessing or navigating
complex data objects as a CDOG model, comprising:
[0057] a) a set of definitions for the relationships between a data
source schema and objects capable of sotring data for an object
language application, wherein the set of definitions is stored in a
repository;
[0058] b) a set of definitions for the relationships between
objects for an object language application,
[0059] c) an object name, a list of objects, or a set of objects
that are to be persisted,
[0060] d) an object or set of objects as a programming module that
contains logic capable of persisting an indicated object or set of
objects,
[0061] e) an input method to inform the programming module of d)
with the location of information related to a), b) and c), and
[0062] f) at least one data source to which persisted data may be
stored.
[0063] A preferred system as described above, is such a system that
does not require any modifications to an object model or the
inclusion of any persistence byte code in the object model in order
to provide persistence for all or a portion of the CDOG model. More
preferred is such a system that provides persistence for a CDOG
model on a distributed network environment. Even more preferred is
such a system for creating or maintaining transparent persistence
of a member selected from the group consisting of a data object, an
object graph model and a portion of an object graph model when a
user of the system is creating, maintaining, accessing or
navigating complex data objects as a CDOG model, wherein d)
comprises a generic ejb stateful session bean. Even more preferred
is such a system that provides persistence for a CDOG model on a
distributed network environment.
[0064] In a particularly preferred embodiment, such a system as
described above does not require any modifications to an object
model or the inclusion of any persistence byte code in the object
model in order to provide persistence for all or a portion of the
CDOG model, wherein d) comprises a generic ejb stateful session
bean.
[0065] In a further embodiment, the invention provides a software
module, or set of modules, for creating or maintaining transparent
persistence of a member selected from the group consisting of a
data object, an object graph model and a portion of an object graph
model when a user of the system is creating, maintaining, accessing
or navigating complex data objects as a CDOG model, comprising:
[0066] i) a software module for creating a set of definitions for
the relationships between a data source schema and its stored data
to objects in a object language application,
[0067] ii) a software module for creating set of definitions for
the relationships between objects in an object language
application,
[0068] iii) a software module providing an input means for an
object name, a list of objects, or a set of objects that are to be
persisted,
[0069] iv) a software module containing the programming logic to
persist an object or set of objects based upon access to (a) a set
of definitions for the relationships between a data source schema
and objects capable of storing data for an object language
application, (b) a set of definitions for the relationships between
objects for an object language application, and (c) an object name,
a list of objects, or a set of objects that are to be persisted,
and
[0070] v) a software module having an input method to inform iv) of
the location of the information related to iv)(a), iv(b) and
iv(c).
[0071] A preferred embodiment of the above invention comprises a
software module, or set of modules, as described above, for
creating or maintaining transparent persistence of a member
selected from the group consisting of a data object, an object
graph model and a portion of an object graph model when a user of
the system is creating, maintaining, accessing or navigating
complex data objects as a CDOG model, comprising software code for
generating, accessing, or maintaining a generic ejb stateful
session bean object as part of the software module of iv).
Preferred is such a software module, or set of modules that does
not require any modifications to an object model or the inclusion
of any persistence byte code in the object model in order to
provide persistence for all or a portion of the CDOG model,
comprising software code for generating, accessing, or maintaining
a generic ejb stateful session bean object as iv). More preferred
is such a software module, or set of modules that provides
persistence for a CDOG model on a distributed network
environment.
[0072] In another preferred embodiment, the invention provides a
software tool comprising the API according to the invention or
interfacing therewith, wherein the software is adapted for
performing the following steps: [0073] a) reading a source
programming object logic model or a database definition in a format
selected from the group consisting of a Unified Modeling Language
("UML") data file, an XML Metadata Interchange ("XMI") data file,
and an Extensible Markup Language ("XMI") file; and [0074] b)
converting the information of (a) into a target member selected
from the group consisting of a database definition XML file, a
database mapping definition file, and a CDOG definition file.
[0075] In a further preferred embodiment, the present invention
provides a software tool as described above that is adapted for
performing at least one of the following additional steps: [0076]
a) displaying a representation of a source programming object logic
model or a database definition file in a format selected from the
group consisting of a UML data file, a XMI data file, and a XML
file; [0077] b) storing a representation of a source programming
object logic model or a database definition file in a format
selected from the group consisting of a UML data file, a XMI data
file, and a XML file; [0078] c) printing a representation of a
source programming object logic model or a database definition file
in a format selected from the group consisting of a UML data file,
a XMI data file, and a XML file; [0079] d) displaying the target
information of (b); [0080] e) storing the target information of
(b); and [0081] f) printing the target information of (b).
[0082] In a still further preferred embodiment the software tool
described above provides target information that is at least one
member selected from the group consisting a CocoBase database
definition repository file, a CocoBase map, a CocoNavigate (or
CBFacade) CDOG definition, a CocoNavigate (or CBFacade) object link
descriptor, and a CDOG object graph definition data file. Further
preferred is such software, wherein the source is a UML/XMI
document containing sufficient DTD information to exchange modeling
information with a UML modeling tool.
[0083] In one embodiment of the software tool according to the
invention, the software tool can be set to automatically generate a
persistence layer that corresponds to the source UML class diagrams
provided by an exported source file from a case tool capable of
exporting UML/XMI, such as Rational Rose, Together and ArgoUML.
[0084] An easy way to understand the job performed by a CDOG
Navigator API, such as the CocoNavigator API, is to imagine it as a
monitor that can provide at least one object to intercept any
accesses to the data objects and their relationships that
constitute the CDOG, as well as any changes to the data source upon
which the CDOG depends, in order to provide a means to persist any
changes to the CDOG (or CDOG model) or related data in the data
source. Any changes to the CDOG (or CDOG model) can then be
propagated by the CDOG Navigator API to a persistent data source
through a CocoBase Enterprise O/R connection. Similarly, persistent
data that updates a data source can be utilized to create a CDOG
model or to update a CDOG model.
[0085] Each CDOG (or CDOG model) managed by the CDOG Navigator API
(or CBFacade) can be associated by the CDOG Navigator API (or
CBFacade) with a CDOG descriptor (such as a file) that may be
utilized to represent all or part of a "navigation model". In this
respect, a navigation model may be abstractly described as
essentially a namespace in which a set of data objects and a set of
link descriptions (i.e., relationship types between data objects)
are each defined. In a preferred embodiment, a data source, data
field, data field size and data field type are listed for each data
object in the set of data objects. In another preferred embodiment,
at least one link description for two data objects, or for a single
data object having a circular link (where the link description is
utilized in conjunction with the CocoNavigator API and CocoBase
mapping tool) contains one or more of the following types of
information (however other related information may be utilized):
[0086] at least one link type (e.g., 1:1, 1:M, M:1 and M:M) between
data objects [0087] at least one link qualifier (currently
supported qualifiers are STD and BEAN) [0088] at least one
associative CocoBase map (optional, for M:M links only) [0089] the
names of the CocoBase maps related to each of the data objects
(usually two maps that are not necessarily distinct), and [0090]
information that may be obtained for each of the CocoBase maps
related to the relationship between two data objects, including:
[0091] the name of a relationship link between the two data objects
[0092] the names of the fields (i.e., keys) in a CocoBase map that
are used to establish a relationship link between two data objects
[0093] the name of a data source for each of the fields (i.e.,
keys) in a CocoBase map that are used to establish a relationship
link between two data objects [0094] the names of the fields (i.e.,
keys) in the associative CocoBase map (optional, for M:M links
only) [0095] the names of a data source for each of the fields
(i.e., keys) in the associative CocoBase map (optional, for M:M
links only) [0096] the name(s) of any java classes corresponding to
fields that would impact upon the relationship between two data
objects [0097] a setting parameter indicating whether the a loading
of a particular CocoBase map that will impact upon a relationship
between two data object should be cascaded to other related map(s)
[0098] a setting parameter indicating whether a deletion of
information from a particular CocoBase map that will impact upon a
relationship between two data object should be cascaded to other
related map(s) [0099] a setting parameter indicating whether an
insertion of information into a particular CocoBase map that will
impact upon a relationship between two data object should be
cascaded to other related map(s), and [0100] a setting parameter
indicating whether an update of information in a particular
CocoBase map that will impact upon a relationship between two data
object should be cascaded to other related map(s).
[0101] Some preferred features provided by the CocoNavigator API
and its associated software, when utilized with the CocoBase
mapping tool, or with a similar mapping tool, are as follows:
[0102] (a) Provides Multiple Navigation Models for the Same CDOG
Model [0103] A preferred embodiment of the CocoNavigator API or an
associated program module is configured to allow many navigation
models to be used with the same set of java classes and CocoBase
maps that are associated with a CDOG model. This preferred
embodiment API, or an associated computer program module, may also
be configured to permit a user to switch dynamically from one such
navigation model to another. Thus, while a given application is
being executed, it is possible to completely change the
relationships between data objects and how CDOGs of a CDOG model
should be managed.
[0104] (B) Circular Link Definitions [0105] A preferred embodiment
of the CocoNavigator API, or an associated computer program module,
is configured to permit a user to create, access, support and
correctly manage circular data object links. In a navigation model,
a circular link may be defined as occurring when a data object is
directly or indirectly linked to itself as part of a CDOG. Such
relationships can be created, accessed, supported and correctly
managed via the CocoNavigator API.
[0106] (c) Bi-Directional and Oriented Links [0107] A preferred
embodiment of the CocoNavigator API, or an associated computer
program module, is configured to permit a user to create, access,
support and correctly manage links between data objects as either a
bi-directional link or as an oriented link. In this embodiment
links between data objects are usually bi-directional links and can
be navigated back and forth as an un-oriented navigational model of
the CDOG model. With such a bi-directional link feature activated,
any object in the navigation model in a given CDOG model can be
used as a navigation entry point. In an oriented link navigation
model, the link may be set as an oriented link accessible from a
single direction. Thus, changes must be made from top down or from
bottom up on a relationship tree representation of the navigation
model, and some actions may need to originate from a pre-set node
of the relationship tree. In this embodiment, such types of links
can be created, accessed, supported and correctly managed via the
CocoNavigator API.
[0108] (d) Dynamic Link Proxy Properties [0109] In a preferred
embodiment, the CocoNavigator API, or an associated computer
program module, is configured to permit a user to populate any
object property (e.g., public field or a getter/setter pair) having
its type declared as an object class with special dynamic proxies
that can monitor and update the state of a relationship link.
Examples of such types of object classes are
thought.Cocobase.navapi.LinkObjProxy of CocoBase and the Sun
Microsystems java class, java.util.Vector. Bi-directional or single
directional object references can be consistently maintained in
this manner, or by other similar logical mechanisms.
[0110] (e) Automatic Synchronization of Object Properties [0111] In
a preferred embodiment, the CocoNavigator API, or an associated
computer program module, can be configured to automatically merge a
data object and its properties into a CDOG navigation model
representation when the class of object being navigated (being
created, accessed, supported or maintained) has a property (e.g., a
field or a getter/setter pair) with a name matching the name of a
corresponding link as defined in the navigation model.
[0112] (f) Pure Object Models [0113] In a preferred embodiment, the
CocoNavigator API, or an associated computer program module, can be
configured to include a data object as a relationship link to
another data object in a navigation model without the need to
declare fields and properties for the data object. Such links
should be limited however to cases where no computer code
dependency will exist between the java classes that will be
associated with such linked data objects of the navigation model.
Thus, such a navigation model can be a pure abstraction, and more
reusable than just a populated version or single hypothetical
instance of the abstraction.
[0114] (g) Customized Link Visitors [0115] In a preferred
embodiment, the CocoNavigator API, or an associated computer
program module, can provide an interface which can be configured to
permit a visitor object to use this interface to visit (e.g.,
access or change) a data object that is part of a CDOG navigation
model. In conjunction with CocoBase, an example of CocoNavigator
API implementing this concept might using a LinkVisitor object
(class). Other similar classes may be defined for this purpose. The
visitor interface provides a way for a user to customize and adapt
the software, and thereby allows a user to extend the functionality
of the CocoNavigator API, or the functionality of an associated
computer program module, to provide a desired customizable behavior
in their CDOG navigation model.
[0116] (h) Distributed Environments [0117] In a preferred
embodiment, the CocoNavigator API, or an associated computer
program module, can be configured to operate as a tool to create,
access, support and correctly manage a CDOG navigation model in a
server environment (e.g., in an EJB container) and to persist any
changes to the CDOG navigation model when a navigation model is
distributed across a local network or when the navigation model
involves a distributed network (e.g., a navigation model
distributed across internet connections). In one aspect, on the
server side of the network, a CDO or a CDOG model of any complexity
sent by clients (e.g., serialized copies) across a local network,
or across a distributed network, can be correctly merged into a
CDOG model by the CocoNavigator API, or by an associated computer
program module. Additionally, the CocoNavigator API, or an
associated computer program module, can be configured to send a CDO
or CDOG model to a client along with link proxies serialized with
parts of the CDO or CDOG model that are being monitored by such
link proxies. By sending the CDO or CDOG model copy along with such
link proxies and associated parts of the CDOG or CDOG model to a
client, dynamic link proxies (described above in (d)) can be used
by the client side. Accordingly, a CDOG navigation model can be
created, accessed, supported, managed and persisted over a
distributed network.
[0118] (i) Group Loading or Lazy Loading of Links [0119] In a
preferred embodiment, the CocoNavigator API, or an associated
computer program module, can be configured to monitor some or all
of the data objects (and associated relationship definitions)
participating in links of a CDOG navigation model. In a more
preferred embodiment, the data objects (and associated relationship
definitions) participating in links of a CDOG navigation model can
be loaded as they are needed (lazy loading) from a persistent data
source or from another type of information repository. This lazy
loading feature can permit a very large CDOG navigation model to be
loaded in a per-link basis as needed. In a more preferred
embodiment, the lazy loading feature can be configured to prevent a
link from being loaded twice and can be configured to detect cycles
of related loads that have been previously loaded. Such
configuration adaptability can be exploited to provide the more
efficient use of the resources for a computer system or network or
for a distributed computer network.
[0120] Some examples of preferred features that can be provided by
the CocoNavigator API and its associated software, which are
particularly enhanced when utilized with the currently existing
CocoBase mapping tool, are as follows:
[0121] (aa) CocoBase Transactions [0122] A preferred embodiment of
the CocoNavigator API or an associated program module is configured
to bind a data object or data object relationship of a CDOG
navigation model with a CocoBase transaction. Such configurations
may be utilized to optimize access to the database server and to
enhance performance of the computer system, or systems, involved
with the CDOG navigation model.
[0123] (bb) Non-CBProp Objects [0124] The CocoNavigator API or an
associated program module can be configured to automatically detect
non-CBProp objects (objects with classes that do not implement the
CocoBase interface known as the CBProp interface), and
automatically create proxies in order to persist such objects as
part of a CDOG navigation model.
[0125] (cc) Virtual Foreign Key Fields [0126] The CocoNavigator API
or an associated computer program module can be configured to use
proxy classes of CocoBase, such as the CocoProxyM classes, when
appropriate. Implementing proxy classes such as the CocoProxyM
classes can provide a system for creating, accessing, supporting,
properly maintaining and persisting virtual foreign key fields
(i.e., foreign key fields do not need to be defined in the object
class for Java programming implementations) by the CocoNavigator
API, or by an associated computer program module.
[0127] (dd) Transparent Persistence [0128] The CocoNavigator API or
an associated computer program module can be configured to use a
configurable network component capable of acquiring and persisting
CDOGs through network APIs and thereby provide persistence
transparently with respect to the applications that are using the
CDOGs. In a preferred implementation, there is provided a software
tool comprising the CocoNavigator API that is adapted for a local
network or for a distributed network environment, wherein the
software tool provides persistence in an object oriented language
environment transparently by implementing a configurable network
component capable of acquiring and persisting CDOGS. Such a concept
may be referred to as transparent persistence in the context of
this API, because persistence can be obtained without requiring
reconfiguring of an existing CDOG model or software application in
order to provide such persistence to a computer software
application.
[0129] (ee) Transparent Persistence with Automated APIs that May be
Further Optionally
[0130] Utilized with a Local or Distributed Implementations Such as
a Session Bean Implementation [0131] The CBFacade or other modules
containing high level API's can be utilized that can function in
place of the CocoNavigator API (or coordinate with it) to automate
many of the transparent persistence functions. Such a software
module or modules can be utilized in concert with a local or
distributed implementation such as a session bean to provide an
easier and quicker establishment of transparent persistence. The
CBFacade can provide the functions as defined in (dd) and the
session bean can provide a communication link between modules such
as a transaction API and the navigation API (and/or with the
CBFacade) to assure that transparent persistence occurrs as
required. Such transparent persistence in the context of this API
can be obtained without requiring reconfiguring of an existing CDOG
model or software application in order to provide such persistence
to a computer software application.
[0132] From the above description of features of the API, and the
features of the CocoNavigator API programming routines described
below, an object computer language programmer can produce an API
having the functionality of the CocoNavigator API described herein.
Essentially the CocoNavigator API has an at least one user access
interface, at least one data source access interface and at least
three main programming modules consisting of the following
programming modules or routines: [0133] I. A programming module or
routine constructed to operate on a computer system and to provide
the following features to a user or to a software program module of
the computer system: [0134] a) a computer programming sub-routine
or sub-module for obtaining from a member selected from the group
consisting of a data source, an information repository, and an
input device, sufficient information to construct a CDOG model
containing one or more CDOGs, [0135] b) a computer programming
sub-routine or sub-module for constructing and loading into the
memory registers of the computer system a CDOG or a CDOG model
representation definition from a data source or other repository,
and [0136] c) a computer programming sub-routine or sub-module for
sending a copy of some portion or all of the CDOG representation
definition to a user or to a software program module on a local
computer system or on a distributed network; [0137] II. A
programming module or routine constructed to operate on a computer
system and to provide the following features to a user or to a
software program module of the computer system: [0138] a) a
computer programming sub-routine or sub-module for monitoring a
user or a software program module on a computer system that has
accessed or changed a portion of a CDOG or CDOG model, which is
included in the CDOG, or CDOG model, representation definition of
(I), above, and obtaining any changes to the CDOG or CDOG model,
[0139] b) a computer programming sub-routine or sub-module for
monitoring a user or a software program module on a computer system
who has obtained a copy of any portion of the CDOG, or CDOG model,
representation definition, and for obtaining a copy of any changes
that the user might have made to any portion of the CDOG, or CDOG
model, representation definition, and [0140] c) a computer
programming sub-routine or sub-module for comparing a copy of a
CDOG, CDOG model, or a representation definition of either the CDOG
or CDOG model, to an original stored version of the CDOG, CDOG
model, or an original stored representation definition for the CDOG
or CDOG model, and for updating the original to incorporate any
changes to a CDOG or a representation definition that are made by
the user or by a software program module; and [0141] III. A
programming module or routine constructed to operate on a computer
system and to provide the following features to a user or software
program module of the computer system: [0142] a) a computer
programming sub-routine or sub-module for storing a new CDOG or
CDOG model, or storing a definition of either the CDOG or CDOG
model, in a data source or in another information repository, and
[0143] b) a computer programming sub-routine or sub-module for
persisting (saving to permanent storage) either a changed portion
of an updated CDOG, an updated CDOG model, or an updated definition
representation for either a CDOG or a CDOG model, to a data source
or to another type of information repository.
[0144] In a more preferred embodiment, the CDOG API according to
the invention, (a preferred embodiment is the CocoNavigator API)
can be written with an interface that accesses and uses
functionalities of the CocoBase mapping tool, associated
programming routines, or associated class libraries. Both the
object code and the source code of the CDOG API are contemplated as
part of this invention.
[0145] In another preferred embodiment, the above described CDOG
API can be accessed to create, maintain, access, navigate and
persisting complex data objects as a CDOG model. In a particularly
preferred aspect, the API can be accessed by a computer software
program such as the CocoBase mapping tool, or by a computer
software program module that is part of a software package
including the API, to provide at least one action selected from the
group consisting of creating, maintaining, accessing, navigating
and persisting complex data objects as a CDOG model. In an even
more preferred aspect, the present invention provides such an API
as part of a software tool package having a feature or method for
displaying or printing a graph or set of tables representing a CDOG
or a CDOG model. In yet another preferred aspect, such a software
tool package including the API provides an interface for editing a
CDOG, a CDOG model, or for editing a representation definition for
a CDOG or a CDOG model to provide a modification that implements a
change to a CDOG, or to its definition.
[0146] As described above, a software component according to the
invention that is capable of persisting all or a portion of a CDOG
may be an Enterprise Java Bean selected from the group consisting
of Stateless, Stateful or even Entity Beans. CocoBase Enterprise
Beans (CBEBs) are a preferred embodiment of the invention and
constitute a set of Enterprise Java Beans build upon or accessing
CocoBase Runtime and EJB APIs to provide persistence in a generic,
efficient and transparent way. Distributed transparent persistence
can be provided without the need for any object model changes or
byte code modifications. CBEBs can be directly deployed on an EJB
server with or without customized settings and are capable of
persisting virtually any Java Object, any Java Object graph or any
portion of the Object graph. The Java Objects of any complexity
that are arbitrarily created by client applications can be
persisted, and the corresponding object classes can be properly
mapped to a CocoBase repository or other object repository such as
a UML XMI repository. Copies of the Java Object, any portion of an
Object Graph, or all of an Object Graph can be automatically
reconciled and the changes can be persisted to a storage
repository.
[0147] The CocoBase Navigation API maps database foreign
key--primary key relationships to object references. The
relationship maps (sometimes referred to herein as navigation
models), like the database maps, are stored in a special CocoBase
repository, or may be converted into an XML file (or files) and
stored in a stand-alone file or directory. The Navigation API
supports 1 to 1, 1 to M, and M to M links in both the object and
relational spaces. For M to M relationships, an associative table
and a corresponding associative map are required, since relational
databases do not directly support M to M relationships.
[0148] A navigation model must be created, or properly reference,
before CocoBase links can be defined. A navigation model is a
namespace used to categorize and store a set of link definitions.
Generally, a single navigation model is sufficient for simple
applications. Multiple navigation models are useful if an
application switches between several relationship configurations.
This allows different views of complex object data for the same set
of underlying database tables. Having relationship mapping
separated from table mapping is unique to CocoBase. Since maps can
be used with multiple link models, it provides reusability at the
mapping level.
[0149] Below is an example of how a client application on an EJB
Server could connect to and use at least on CBEB to provide
transparent persistence, in a local non-distributed
environment.
EXAMPLE 1
[0150] TABLE-US-00001 // Set up the connection class CBFacade cbf =
CBFacade.create("thought.CocoBase.- CBFacadeLocal"); Properties
props = new Properties( );
props.put("cocosource.name",thought.CocoBase.CocoPowderPlugin20);
props.put("cocosource.jdbcdriver","oracle.jdbc.driver.OracleDriver");
props.put("cocosource.url","jdbc:cocoprop=jndiurl=java:comp/
env/jdbc/sfcmbhome"); props.put("cocosource.user","SCOTT");
props.put("cocosource.password","TIGER");
props.put("cocosource.navmodel","CompanyExample");
cbf.connect(props);// create a complex object having myObj as the
root of the tree // create an example object MyObject myObj = new
MyObject( ); myObj.setSomeField(someValue); // now ask the Facade
to load the object that matches the set fields (QBE) myObj =
cbf.load(myObj); // create an example object
myObj.setSomeOtherField(someOtherValue); // now ask the CBFacade to
save the changed values cbf.save(myObj); ... // do some more
changes to myComplexObject and save it again ... cbf.save(myObj);
...
[0151] Implemention of Examples 2-4, below, collectively provide
persistence via a session bean as described generally by the
following text.
[0152] The CBSession EJB
[0153] The CBSession EJB is a Stateful Session Bean that works as
an abstraction layer for CocoBase runtime classes. It provides
generic transparent persistence to Java objects of any complexity
in a simple yet elegant way. It is designed to run in any Java
Application Server, thus combining CocoBase transparent object
persistence capabilities with most features provided by such
servers, such as transaction management, security, resource pooling
and so forth.
[0154] The CBSession bean is very simple and easy to use. Here is
an illustration of how the session bean of Examples 2-4, below
might be implemented and used: TABLE-US-00002 ... Context ic = new
InitialContext(...); Object ref = ic.lookup("CBSession");
CBSessionHome home = (CBSessionHome) PortableRemoteObject.narrow
(ref,CBSessionHome.class); String cocourl =
"CBSession;cocorep=configresource:/resources/
MyConfigFile.properties:cocoprop=primary
key.lookup=false,dynamic.querying=true,jndiurl=java:comp/
env/jdbc/demoPool" // connects to a CBSession CBSession cbSession =
null; try { cbSession = home.create(cocourl,"MyNavModel",null);
cbSession.setDebugLevel(1); } catch (Exception e) {
System.out.println("Could not open CBSession due to " + e); return;
} MyComplexObject obj = new MyComplexObject( ); ... // populate
values for querying obj.setValues(...); ... // load object graph
obj = (MyComplexObject) cbSession.load(obj,"MyMap"); ... // do some
changes to obj graph ... // save changes
cbSession.save(obj,"MyMap"); ... See CBSession interface for more
details. Deploying the CBSession bean ----------------------------
Requirements: coco_home/classes and coco_home/demos must be in your
App Server classpath. Ant 1.2 or later must be installed in order
to compile/regenerate deployable jar files.
[0155] The Ant script build.xml will generate a deployable jar file
with the CBSession bean for a particular server. Make sure the
entry in the beginning of the build.xml file has the entry
TABLE-US-00003 <property name="cocohome"
value="c:/thought/cocodemo3tier31" /> correctly specified.
[0156] Targets currently defined include WebLogic 6.1, JBoss 2.4
and a generic jar file. Each subdirectory corresponds to a server,
containing the standard descriptor and proprietary descriptors for
that server. These descriptors can be modified in case it is
required to do so.
[0157] For example, the jar file for JBoss can be generated as
follows: os-prompt>ant jboss
[0158] See build.xml for available targets.
[0159] IMPORTANT: In order to have CBSession working for a
particular application model, all the required java classes and
resources (i.e. the map pre-load configuration properties file, the
navigation model properties file) must be in the classpath (for
example, these classes and resources could be copied to the
coco_home/demos/resources directory, provided this directory is
included in the app server classpath). Another alternative would be
to add all needed classes and resources to the CBSession bean jar
file. This can be done simply by copying these classes and
resources to the directory corresponding to the target server and
running the ant script again. For example, for JBoss, the following
directory structure would generate a jar file with all classes and
resources: TABLE-US-00004 cbsession ... jboss ejb-jar.xml jboss.xml
resources MyConfigFile.properties MyNavModel.properties my app
package AppClass1.class AppClass2.class AppClass3.class ...
Examples 2-4, source code for CBSession Bean and its use are as
follows:
EXAMPLE 2
[0160] TABLE-US-00005 Source Code File Name = CBSession.java
package thought.CocoBase.ejbs.cbsession; import
java.rmi.RemoteException; import javax.ejb.EJBObject; /** *
CBSession remote interface * <p> * Copyright (c) 2001 THOUGHT
Inc. All Rights Reserved. * * @author Alexandre Jonatan Martins *
@version 0.9, August 2001 */ public interface CBSession extends
EJBObject { /** * Invokes
<code>load(Object,String)</code> sending *
<code>object.getClass( ).getName( )</code> as the
<code>mapName</code> * @param obj the example object *
@return the loaded object */ public Object load(Object obj) throws
RemoteException; /** * Loads an object from the database * @param
obj the <i>example</i> object * @param mapName the map
name corresponding to the class of obj * @return the loaded object
*/ public Object load(Object obj, String mapName) throws
RemoteException; /** * Invokes
<code>save(Object,String)</code> sending *
<code>object.getClass( ).getName( )</code> as the
<code>mapName</code>. * @param obj the example object
*/ public void save(Object obj) throws RemoteException; /** * Saves
an object to the database * @param obj the
<i>example</i> object * @param mapName the map name
corresponding to the class of obj * @return the loaded object */
public void save(Object obj, String mapName) throws
RemoteException; /** * Invokes
<code>delete(Object,String)</code> sending *
<code>object.getClass( ).getName( )</code> as the
<code>mapName</code>. * @param obj the example object
*/ public void delete(Object obj) throws RemoteException; /** *
Deletes an object from the database * @param obj the
<i>example</i> object * @param mapName the map name
corresponding to the class of obj */ public void delete(Object obj,
String mapName) throws RemoteException; /** * Returns app server
session debug level * @return <code>true</code> if
debug is on; <code>false</code> otherwise */ public int
getDebugLevel( ) throws RemoteException; /** * Sets app server
session debug level as follows: * <p><code><pre>
* 1 - prints basic session response * 2 - prints navigation info +
level 1 info * 3 - prints detailed navigation info + level 2 info *
4 - prints cocobase transaction info + level 3 info * 5 - prints
cocobase driver and jdbc info + level 4 info *
</pre></code></p> * @param debug the debug level
* @param mapName the map name corresponding to the class of obj */
public void setDebugLevel(int level) throws RemoteException; }
EXAMPLE 3
[0161] TABLE-US-00006 Source Code File Name = CBSessionHome.java
package thought.CocoBase.ejbs.cbsession; import
java.rmi.RemoteException; import javax.ejb.CreateException; import
javax.ejb.EJBHome; import java.util.Properties; /** * CBSession
home interface * <p> * Copyright (c) 2001 THOUGHT Inc. All
Rights Reserved. * * @author Alexandre Jonatan Martins * @version
0.9, August 2001 */ public interface CBSessionHome extends EJBHome
{ /** * Creates a CBSession. Properties will be read from the
evironment entries in * the ejb descriptor. The following
properties are recognized: * <p><code><pre> *
cocosource.url = cocobase_connection_url_string * cocosource.name =
cocobase_driver_name_string * cocosource.user = user_name_string *
cocosource.password = user_password_string * cocosource.autoclose =
"true" | "false" * cocosource.autotrans = "true" | "false" *
cocosource.navmodel = navigation_model_string *
</pre></code></p> */ public CBSession create()
throws RemoteException, CreateException; /** * Creates a CBSession.
The behavior of the session data source can be customized by * a
properties object containing specific configuration details. The
following * properties are recognized: *
<p><code><pre> * cocosource.name =
cocobase_driver_name_string * cocosource.user = user_name_string *
cocosource.password = user_password_string * cocosource.autoclose =
"true" | "false" * cocosource.autotrans = "true" | "false" *
</pre></code></p> * @param cbUrl the CocoBase
connection url * @param navModel the name of the navigation model
(if not provided, uses default navigation model) * @param props
configuration properties */ public CBSession create(String cbUrl,
String navModel, Properties props) throws RemoteException,
CreateException; }
EXAMPLE 4
[0162] The CBFacadeRemote
[0163] The CBFacadeRemote is a Wrapper API that works with the
CBSession EJB (described in detail previously) It provides a high
level API that simplifies the task of remote programming and
distributed usage in a very elegant API. It is compatible with an
interface which makes it possible to swap out Local and Distributed
implementations at will, and at runtime. It is designed to run in
any Java Application Server, thus combining CocoBase transparent
object persistence capabilities with most features provided by such
servers, such as transaction management, security, resource pooling
and so forth.
EXAMPLE 4
[0164] The present may be embodied in specific forms other than
those particularly described above or illustrated by the appended
drawings. Upon viewing the present application preferred
embodiments and other descriptions herein of the present invention,
variations and other implementations that do not depart from the
spirit and scope of the present invention will be apparent to one
of routine skill in this field. Such variations and other
implementations are considered part of the present invention and
within the scope of the appended claims. Accordingly, reference
should be made to the appended claims, rather than to the forgoing
specification and drawings, as indicating the scope of the present
invention.
APPENDIX 1
From SQL to Transparent Persistence using CocoBase Enterprise
OR
[0165] This document is a brief overview of how to create Java
applications that use CocoBase Transparent Persistence features
starting from SQL database tables. Such Transparent Persistence can
be run locally on a system instead of in a distributed environment.
A local application server or a JSP server such as TomCat can be
utilized to connect a JSP to a database and provide persistence of
objects in the model or database.
Table Mapping
[0166] Suppose a set of database tables was defined as follows:
TABLE-US-00007 CREATE TABLE COMPANY( ID NUMERIC, NAME VARCHAR(50),
PRIMARY KEY(ID)) CREATE TABLE DEPARTMENT( ID NUMERIC, NAME
VARCHAR(50), COMPANY NUMERIC, PRIMARY KEY(ID), FOREIGN KEY(COMPANY)
REFERENCES COMPANY(ID)) CREATE TABLE EMPLOYEE( ID NUMERIC, NAME
VARCHAR(50), SALARY REAL, DEPARTMENT NUMERIC, MANAGER NUMERIC,
PRIMARY KEY(ID), FOREIGN KEY(DEPARTMENT) REFERENCES
DEPARTMENT(ID))
[0167] The steps to create a CocoBase Map from a given table are
detailed below.
1) Connect to the CocoBase Repository
[0168] Launch CocoBase and go to File->Open New DB Connection to
open the login dialog.
[0169] In the dialog, select the JDBC driver/user/password to be
used to connect to the CocoBase repository and click on the
Login>button presented in the dialog box or window.
2) Create Map from Table
[0170] If login was successful, a dialog box will appear indicating
a successful login and providing a number of task options and/or a
tool bar with pull down windows.
[0171] Check the box Generate New Map From Table in the dialog box
or window and click on the button Launch.
[0172] A window will appear with a tree indicating connections and
tables that are available.
[0173] Expand the branches on the tree in the dialog to see the
tables available in the database and then select one of the tables.
Click on the button Next>to go to the window with the Map field
details, verify if the information is correctly matching the table
definition and that the Map name is appropriate. The Map can be
modified at this point by changing the names or types of the fields
and inserting or deleting fields.
[0174] Click on the button Finish to create the new Map from the
selected table. A dialog will be prompted asking to confirm the
creation of the Map. Click on the button Continue Map Create to
confirm the creation of the new Map. A message will be prompted
confirming that the Map was successfully generated and is already
in the CocoBase repository.
[0175] Click on the button Ok button of the pop-up dialog to
continue. This procedure must be repeated for all the tables
containing information relevant to your application. To start again
in the Map creation Window of the earlier present dialog (or at the
top of the tool bar on the interface), select the menu item
File ->New Map from Table.
3) Verify the results
[0176] Go to File->Edit Map in the dialog to open the Map editor
and verify if the Maps were created accordingly.
Relationship Mapping
[0177] Once all necessary database tables are mapped, it is
possible to create Link definitions between the Maps so that 1-1,
1-M and M-M relationships between objects can be transparently
managed by CocoBase. The steps to create a Link definition are
detailed below.
1) Choose Link Model
[0178] Before creating a Link, it is necessary to have a Link model
created. A Link model is a set of Link definitions. Multiple Link
models are useful when an application needs to switch between
several relationship configurations, since it allows different
views of complex object data over the same set of underlying
tables. The idea of having relationship mapping separated from
table mapping is unique of CocoBase. It provides reusability at the
mapping level, since a given Map can be reused across multiple Link
models.
[0179] Usually, one single Link model is sufficient for a simple
application. To create a link model, right click on the Links
branch in the Map editor tree. A pop-up menu like the following
will appear giving options such as New Model, Import Model, Save,
Save to location, Reload, and the like.
[0180] Select the option New Model . . . and enter the name of the
new Model in the input dialog that will appear next.
[0181] The new Link model will be inserted as a sub-node in the
editor tree.
2) Create Link Definition
[0182] In order to create a new Link for that model, right click on
the model to activate the model pop-up menu and select the menu
item New Link in the dialog.
[0183] After clicking on the menu, a new empty Link definition will
be inserted in the selected model. Expand the model branch and
click on the new Link definition to see its details in a detail
dialog.
[0184] Although totally unconstrained, a Link definition would
normally be created for each foreign-primary key relationship in
the database tables or, in the case of many-to-many relationships,
for each associative table.
[0185] A Link definition is basically a combination of two roles,
each having the following information:
Map Name--the name of the Map participating in the relationship
Link Name--the name of the link that connects to the Map in the
opposite role. It normally matches the name of the object property
(field or get/set method pair) that holds instances of the related
objects.
Key Fields--the comma-separated list of fields defined according to
the following guidelines:
[0186] If this role is on the "one" side of a one-to-one or
one-to-many link, this is the list of the fields in the map that
correspond to the primary key defined in the underlying table
[0187] If this role is on the "many" side of a one-to-many link,
this is the list of the fields in the map that correspond to the
foreign key defined in the underlying table [0188] If this is a
role of a many-to-many links, this is the list of the fields in the
map that correspond to the primary key defined in the underlying
table Java Class--the full qualified name of the Java class that
will be instantiated when the relationship is loaded from the
database. This is normally a class corresponding to the Map
specified in the opposite role. Cascade Load--indicated if this
role is going to load related object instances. Cascade
Insert--indicated if this role is going to insert related object
instances. Cascade Delete--indicated if this role is going to
delete related object instances. Cascade Update--indicated if this
role is going to update related object instances. M:M Key
Fields--This is relevant only for many-to-many Link definitions and
is the comma-separated list of the fields in the associative map
that refer to the Key Fields of this role. In this case, the name
of associative map must be specified in the box M:M Map Name.
[0189] Examples of Link definitions are given in published CocoBase
literature. Click on the appropriate boxes to edit the Link
definition for the model being defined. Repeat this procedure for
each table relationship that is relevant to the application being
developed.
3) Save Link Definitions
[0190] Once Link definitions are complete, select the branch Links
in the editor tree right and click on it to access the pop-up menu.
Click on the option Save to save your work.
[0191] Note that unlike CocoBase Maps, Link models are not kept in
the CocoBase repository in the current release. Instead, for each
Link model, CocoBase will create a property file called
modelname.properties containing all the Link definitions for that
model. This property file is stored under the demos/resources
directory (by default--although this can be overridden). As long as
the property file describing the Link model is in the classpath
(either directly or in a subdirectory called resources), CocoBase
runtime classes will load the model and register the navigation
information.
CocoBase Transparent Persistence
[0192] In the previous sections show above in this appendix, it was
demonstrated how to map database tables and relationships using
CocoBase. In this section, it is shown how CocoBase runtime classes
can be used to provide transparent persistence to a Java Object
Model which corresponds to the created Maps and Links.
Transparent Persistence with CocoBase Maps and Models
[0193] CocoBase accomplishes transparent persistence with java
object models without using bytecode manipulation, proprietary
interfaces or class hierarchy intrusion. This means that no special
classes or interfaces are needed in the Object Model in order to do
persistence with CocoBase. The only requirement is that they must
have a default constructor with no arguments.
[0194] There are 3 basic Runtime components that are involved in
the transparent persistence of objects: [0195] The CocoBase Runtime
O/R mapping class that wrappers the JDBC driver and issues queries
and does the actual persistence calls. This is a class such as
thought.CocoBase.CocoPowder or thought.CocoBase.CocoPowderPlugin20
(forjdbc 2.0 connections). [0196] The thought.CocoBase.Transaction
object that can track changes of instances, and acts as a change
`buffer`. If a Transaction object is used, then it only calls a
CocoBase Runtime driver--O/R mapping runtime class--when the
txn.commit( ) is called. [0197] The
thought.CocoBase.navapi.Navigator object that can track and detect
changes in relationships based on Link definitions.
[0198] The Navigator class can function in conjunction with a
Transaction object or it can function standalone. While complex
object graphs can be transparently managed directly by the
Navigator and without the Transaction object, the use of the
Transaction object is generally preferred because of its buffering
and update optimizations which only persist those attributes that
have changed.
Creating Applications with CocoBase Transparent Persistence
[0199] Once Links and Maps are properly created, go to
File->Generate Java Code in the main CocoAdmin Dialog to
generate Java classes. The `Default CocoNavigate Java Object` code
generation target will generate a pure java class with no CocoBase
interfaces.
[0200] After classes have been generated and compiled, CocoBase
runtime classes can be used to persist instances of these classes.
First, open a CocoBase connection as follows: TABLE-US-00008
CocoDriverInterface myBase = CocoDriver.getCocoDriver(
"thought.CocaBase.CocoPowder", "org.hsql.jdbcDriver",
"jdbc:HypersonicSQL:hsql://localhost;cocoprop=cocofactory=
CocoProxyFactory", "sa", "" ) if(myBase.connect( ) == -1) {
System.out.println("Failed connect!"); System.exit(1); } ...
[0201] Then create a CocoBase transaction object to manage any
objects that are retrieved. Notice how the transaction object is
configured through parameters and property settings. TABLE-US-00009
thought.CocoBase.Transaction cocoTxn = new
thought.CocoBase.Transaction(myBase, false); Properties
cocoTransProps = new Properties( );
cocoTransProps.put("preserveCommit","true");
cocoTransProps.put("commitconnection","true");
cocoTransProps.put("throwExceptions","true");
cocoTransProps.put("updateOnlyChangedColumns","true");
cocoTxn.setProperties(cocoTransProps); // Begin a new transaction.
cocoTxn.begin( ); ...
[0202] Then open a CocoBase Navigator object with the Navigation
model to be used and also we register the Transaction object with
the Navigation model: TABLE-US-00010 // Instantiate a Navigator
with the Link model created from // the UML/XMI document
thought.CocoBase.navapi.Navigator navigator = new
thought.CocoBase.navapi.Navigator (myBase, "company"); // Assign
the current transaction to the Navigator
navigator.setTransaction(cocoTxn);
[0203] Now select the top level node to work with. Notice our use
of a CocoProxyM class which `wrappers` the pure java object model
class and gives the class the compatibility with CocoBase through
java reflection instead of requiring any special interfaces in the
java class itself: TABLE-US-00011 // Setup our object to query
Department dept = new Department( ); department.setName("SALES");
// This will read & bind all `Department` objects to the
transaction. Vector deptVector = myBase.selectAll( new
thought.CocoBase.CocoProxyM(dept), "Department");
[0204] Now it is possible to step through each of these objects and
tell the retrieved object to be navigated through the loadAllLinks
method which does the automatic navigation for that object:
TABLE-US-00012 for(int i=0; i< deptVector.size( ); i++) {
Department d = (Department)deptVector.elementAt (i); // Because the
cascadeLoad flag is set to true in the direction //
Department->Employees, the employees link will load
automatically d = navigator.loadAllLinks(d, "Department"); . . .
Vector emps = d.getEmployees( ); for (int j=0; j<emps.size( );
j++) { // raise salaries by 20% emp.setSalary(emp.getSalary(
)*1.2); . . . } . . . // Once changes are made to an object graph
those changes can be // synchronized using the updateAllLinks
method such as: navigator.updateAllLinks(d, "Department",true);
}
[0205] You can then commit the buffered changes with:
cocoTxn.commit ( );
[0206] These code introductions are quite small, and can be done
entirely server side with Entity or Session beans in J2EE
environments with no model or object model intrusion. And for local
non-j2ee apps the application intrusion is incredibly small with
only the `load`, `synchronize` and `persist` operations requiring a
single method call for each root node.
[0207] The Navigator supports one-to-one, one-to-many &
many-to-many link definitions with cycle detection. It also detects
this locally or by reconciling serialized or copied objects without
object model or bytecode intrusion. This is truly transparent
persistence that's architected and designed for the VM oriented
Java language. There are also more advanced applications included
in the demos/pguide/navapi subdirectory that demonstrate all of the
mapping one-to-one, one-to-many & many-to-many relationships as
well as an EJB using the Navigator system to manage a graph of java
objects.
CONCLUSION
[0208] This Appendix is an Example describing how to add CocoBase
Transparent Persistence to Object Models and applications from SQL
database tables (graphic dialogs have been omitted for simplicity,
and the options and dialogs may vary somewhat with new releases).
This can be done in a local non-distributed environment. A wrapper
can be used to wrapper objects and the CBSession class objects
(Transparent Persistence mechanism). It is only a brief overview of
what can be done with CocoBase. The architecture and implementation
presented here is uniquely suited to work in every application from
the tiny local application to the enterprise J2EE and to do so with
superior performance and manageability.
* * * * *
References