Summary

Enterprise messaging is all about asynchronous requests, reports, or events that are used by enterprise applications. Message-Oriented Middleware (MOM) acts as an intermediary, and provides a common and reliable way for programs to create, send, receive, and read messages on any distributed enterprise system. The Java Message Service is an API for accessing such message systems.

The messaging models that are supported by JMS are the Publish/Subscribe messaging model and the Point-to-Point messaging model. In the Publish/Subscribe model, a client publishes a message to a topic, and by subscribing, multiple clients are informed of the message. In the Point-to-Point model, even though there may be multiple senders of messages to a queue, there is ultimately only a single potential receiver for each message.

JMS can be used to develop enterprise applications, in enterprise integration and mobile messaging. Most MOM applications tend to follow a small number of patterns. These patterns allow quick decisions to be made on which product features to use. Without these design patterns, the choice can be overwhelming. These patterns also define how specific messaging errors have to be handled. In the next chapter we will begin with the fundamentals of JMS programming.