Introduction: Messaging resources
WebSphere Application Server supports asynchronous messaging as a method of communication based on the Java Message Service (JMS) and Java Connector Architecture (JCA) programming interfaces. These interfaces provide a common way for Java programs (clients and J2EE applications) to create, send, receive, and read asynchronous requests, as messages.
Besides using the programming interfaces directly to explicitly poll for messages, WAS also supports the use of message-driven beans as asynchronous message consumers. A message-driven bean is invoked by the EJB container when a message arrives at the destination that it is configured to listen on, without an application having to explicitly poll the destination.
To handle non-JMS requests inbound to WAS from enterprise information systems, message-driven beans use a Java Connector Architecture (JCA 1.5) resource adapter written for that purpose. In the JCA 1.5 specification, such message-driven beans are commonly called message endpoints or simply endpoints. You use a J2C activation specification to configure such message-driven beans as JCA 1.5 resources.
Message-driven beans that implement the javax.jms.MessageListener interface can be used for JMS messaging. For JMS messaging, message-driven beans can use a JCA-based messaging provider such as the default messaging provider that is part of WAS. You use a J2C activation specification to configure such message-driven beans as JCA 1.5 resources. For compatibility with WAS v5, one can configure JMS message-driven beans against a listener port.
Use the administrative console to administer the WAS support for asynchronous messaging. For example, one can configure JCA resource, adapters, J2C activation specifications, JMS providers, and JMS resources, and can control the activity of messaging services.
Tools for working with messaging include the following:
- Rational Application Developer for developing and packaging J2EE applications that use JMS, message-driven beans, and other programming techniques for messaging.
- Assembly tools such as the Application Server Toolkit (AST) or Rational Web Developer for working with the packaging and deployment descriptors for WebSphere applications, as described in Assembling applications
- Product systems administration tools for installing and managing WebSphere applications.
For more information about implementing enterprise applications that use asynchronous messaging, see the following topics:
- Learning about messaging with WebSphere
- Installing a messaging provider
- Maintaining V5 default messaging resources
- Using JMS resources of WebSphere MQ
- Using JMS resources of a generic provider
- Administering support for message-driven beans
- Programming to use asynchronous messaging
- Troubleshooting WebSphere messaging