In this chapter we discuss the Java Message Service API before moving on to Message-driven beans. In particular we will cover:
Java Message Service (JMS) API
Point-to-point and publish/subscribe messaging models
Queue producer and consumer examples
Topic producer and consumer examples
Message-driven beans (MDBs)
MDB activation configuration properties
MDB lifeCycle
Sending message confirmation to a client
MDBs and transactions
So far our examples have all been synchronous. For example, a client invokes a session bean which performs some operation while the client waits. When the session bean completes its operation (or operations), control is passed back to the client and the client continues with the remaining operations. For some applications an asynchronous mode of operation is more appropriate, particularly in business to business applications. For example, a client may send a message requesting that an order be processed. The order processing may take some time...