Major Components WebLogic JMS Architecture

Understanding WebLogic JMS 2-3

2.1.3.1 Major Components

The major components of the WebLogic JMS Server architecture, as illustrated in Figure 2–2 , include: ■ JMS servers that can host a defined set of modules and any associated persistent storage that reside on a WebLogic Server instance. ■ JMS modules contains configuration resources such as queues, topics, and connections factories and are defined by XML documents that conform to the http:xmlns.oracle.comweblogicweblogic-jms1.0weblogic-jm s.xsd schema. ■ Client JMS applications that either produce messages to destinations or consume messages from destinations. ■ JNDI Java Naming and Directory Interface, which provides a resource lookup facility. JMS resources such as connection factories and destinations are configured with a JNDI name. The runtime implementations of these resources are then bound into JNDI using the given names. ■ WebLogic persistent storage file store or JDBC-accessible for storing persistent message data.

2.2 Understanding the Messaging Models

JMS supports two messaging models: point-to-point PTP and publishsubscribe pubsub. The messaging models are very similar, except for the following differences: ■ PTP messaging model enables the delivery of a message to exactly one recipient. ■ Pubsub messaging model enables the delivery of a message to multiple recipients. Each model is implemented with classes that extend common base classes. For example, the PTP class javax.jms.Queue described at http:java.sun.comjavaee5docsapijavaxjmsQueue.html and the pubsub class javax.jms.Topic described at http:java.sun.comjavaee5docsapijavaxjmsTopic.html both extend the class javax.jms.Destination described at http:java.sun.comjavaee5docsapijavaxjmsDestination.html . Each message model is described in detail in the following sections.

2.2.1 Point-to-Point Messaging

The point-to-point PTP messaging model enables one application to send a message to another. PTP messaging applications send and receive messages using named queues. A queue sender producer sends a message to a specific queue. A queue receiver consumer receives messages from a specific queue. The following figure illustrates PTP messaging. Note: The terms producer and consumer are used as generic descriptions of applications that send and receive messages, respectively, in either messaging model. For each specific messaging model, however, unique terms specific to that model are used when referring to producers and consumers.