The Java Community Process(SM) Program - JSRs: Java Specification Requests - detail JSR# 153

Original Java Specification Request (JSR)

Identification | Request | Contributions | Additional Information

Original Summary: The Enterprise JavaBeans 2.1 specification extends the existing Enterprise JavaBeans 2.0 specification with new features, including support for JAXM message-driven beans, enhancements to EJB QL to support aggregate and other operations, support for linking of messaging destinations, support for web services usages within EJB, and a container-managed timer service.

Section 1. Identification

Submitting Member: Sun Microsystems, Inc.

Name of Contact Person: Linda DeMichiel

E-Mail Address: linda.demichiel@sun.com

Telephone Number: +1 408 276 7057

Fax Number: +1 408 276 7191

Specification Lead: Linda DeMichiel

E-Mail Address: linda.demichiel@sun.com

Telephone Number: +1 408 276 7057

Fax Number: +1 408 276 7191

Supporting this JSR:

ATG
BEA
Borland
Compaq
HP
Fujitsu
IBM
IONA
Oracle
Persistence
Silverstream

Section 2: Request

2.1 Please describe the proposed Specification:

The Enterprise JavaBeans architecture is a component architecture for the development and deployment of component-based distributed business applications. Applications written using the Enterprise JavaBeans architecture are scalable, transactional, and multi-user secure. These applications may be written once, and then deployed on any server platform that supports the Enterprise JavaBeans specification.

The purpose of the Enterprise JavaBeans 2.1 specification is to address a number of open areas in the Enterprise JavaBeans 2.0 specification and to augment the new functionality that was added in Enterprise JavaBeans 2.0 in response to the needs of the community.

The areas we intend to address are the following. The main goal of this JSR is to deliver these new features into the EJB specification in a timely manner. This goal will likely limit what other features can be incorporated. This JSR is intentionally limited in scope and focuses on well-understood technology so that it will be achievable in a short time frame and complement the goals and schedule of J2EE 1.4.

* Support for the use of Message-Driven Beans with JAXM messaging.

Enterprise JavaBeans 2.0 introduced the message-driven bean as a new component type in the EJB architecture. Use of message-driven beans in EJB 2.0, however, is limited to the Java Message Service API. With the growing need for Enterprise JavaBeans to support use with web services, it becomes important to extend the use of message-driven beans to support JAXM (the Java APIs for XML Messaging) in addition to JMS. This will support the asynchronous delivery of XML business documents by means of the message-driven bean type.

* Enhancements to EJB QL

Enterprise JavaBeans 2.0 introduced EJB QL, the Enterprise JavaBeans query language to provide for the portable definition of finder methods for entity beans with container-managed persistence. EJB QL, as introduced in EJB 2.0, provides a basic query language for the navigation among related entities and the selection of entities according to basic properties, but provides limited or no support for certain operations that are common in other query languages, such as aggregate operations (e.g. ORDER BY). Enterprise JavaBeans 2.1 will augment EJB QL with aggregate and other operations and extend the range of queries that EJB QL can support.

* Support for Linking of Message Destinations

Enterprise JavaBeans 2.0 provided support for integration with JMS, the Java Message Service, and introduced the message-driven bean component type, but did not provide mechanisms for composing applications by declaratively specifying the linking of destinations among messaging consumers and producers. EJB 2.1 will augment EJB deployment descriptor mechanisms to tie together message consumers and producers through the linking of destinations to allow the flow of messages across a network of destinations to be specified by the Bean Provider and/or Application Assembler.

* Timers

Applications that model workflow business processes are dependent on notifications that certain temporal events have occurred in order to effect the semantic state transitions that are specific to the application. A timer service is a container-managed service that provides the basic infrastructure to allow enterprise beans to schedule callback methods by registering them with the container. The container provides a reliable and transactional notification service for the enterprise beans that schedule such timed events. Timer notifications may be scheduled to occur at a specific future time or at specific recurring intervals.

* Support for Web Services Usages

Enterprise JavaBeans 2.1 will include support for the necessary elements to enable enterprise beans usage with web services. This will include, among other items, expanding the environment support and deployment descriptor infrastructure for enterprise beans that use JAX-RPC and JAXM to access service endpoints or to implement web service endpoints.

2.2 What is the target Java platform? (i.e., desktop, server, personal, embedded, card, etc.)

Java 2, Enterprise Edition.

2.3 What need of the Java community will be addressed by the proposed specification?

As described above, this specification will enhance the capabilities of Enterprise JavaBeans, allowing developers to provide more sophisticated applications and achieve better integration with other J2EE platform technologies.

2.4 Why isn't this need met by existing specifications?

These features are specific to Enterprise JavaBeans, which does not yet provide them.

2.5 Please give a short description of the underlying technology or technologies:

The Enterprise JavaBeans architecture is a component architecture for the development and deployment of component-based distributed business applications. It is part of the J2EE Platform.

2.6 Is there a proposed package name for the API Specification? (i.e., javapi.something, org.something, etc.)

javax.ejb

2.7 Does the proposed specification have any dependencies on specific operating systems, CPUs, or I/O devices that you know of?

No

2.8 Are there any security issues that cannot be addressed by the current security model?

No

2.9 Are there any internationalization or localization issues?

No

2.10 Are there any existing specifications that might be rendered obsolete, deprecated, or in need of revision as a result of this work?

The proposed specification will supersede the Enterprise JavaBeans 2.0 specification. The intent is that the Enterprise JavaBeans 2.0 specification will be augmented.

2.11 Please describe the anticipated schedule for the development of this specification.

The EJB 2.1 schedule will track the schedule for J2EE 1.4.

2.12 Please describe the anticipated working model for the Expert Group working on developing this specification.

The expert group will use email for most interactions, and will hold teleconferences to discuss open issues.

Section 3: Contributions

3.1 Please list any existing documents, specifications, or implementations that describe the technology. Please include links to the documents if they are publicly available.

Enterprise JavaBeans Specification, Version 2.0
http://java.sun.com/products/ejb/docs.html

Java 2 Platform, Enterprise Edition Specification, Version 1.3
http: //java/sun/com/j2ee/docs.html

Java Message Service, Version 1.0.2.
http://java.sun.com/products/jms

JSR 67: Java API for XML Messaging (JAXM)

JSR 101: Java API for XML-based RPC (JAX-RPC)

JSR 109: Implementing Enterprise Web Services

JSR 112: J2EE Connector Architecture 2.0

JSR: Java 2 Platform, Enterprise Edition Specification, Version 1.4

3.2 Explanation of how these items might be used as a starting point for the work.

The Enterprise JavaBeans 2.0 architecture specification will be used as the basis for this work.

Section 4: Additional Information (Optional)

4.1 This section contains any additional information that the submitting Member wishes to include in the JSR.

None