Java Message Service (JMS)

Remote Procedure Call (RPC) systems, including Java RMI, are synchronous -- the caller must block and wait until the called method completes execution, and thus offer no potential for developing loosely coupled enterprise applications without the use of multiple threads. in other words, RPC systems require the client and the server to be available at the same time. however, such tight coupling may not be possible or desired in some applications. message-oriented middleware (MOM) systems provide solutions to such problems. they are based on the Asynchronous interaction model, and provide the specified action of a message queue that can be accessed into ss a network. note, however, that messaging here refers to asynchronous requests or events that are consumed by enterprise applications and not humans as in electronic mail (email ). these messages contain formatted data that describe specific business actions.

Meaning:

RPC is a synchronous communication. After a message is sent, the sender of the message must wait for the event to be processed before proceeding with the subsequent work. During the waiting period, the sender is in a blocking state. In the RPC system, the client and server must be online at the same time, but this requirement is usually difficult to meet. At the same time, mom is based on the Asynchronous interaction mechanism and abstracts a message queue. This message queue allows access over the network. Note that the "message" mentioned here refers to the requests or events generated in enterprise applications, rather than the commonly used email messages. The message passed in mom contains normalized data. These data are used to express specific business events (actions.

A jms application is composed of the following parts:

• A jms provider: a messaging system that implements the JMS specification.
• JMS clients: Java applications that send and receive messages.
• Messages: objects that are used to communicate information between JMS clients.
• Administered objects: preconfigured JMS objects that are created by an administrator for the use of JMS clients.

A jms application consists of the following parts:

• JMS provider: a message system that implements the JMS standard.
• JMS User: Java application that sends and receives messages.
• Message: Objects transmitted between customers of JMS.
• Management Objects: pre-set JMS objects created by the Administrator and used by JMS customers.

Link: getting started with Java Message Service (JMS)

Location: http://java.sun.com/developer/technicalArticles/Ecommerce/jms/

The Java Message Service API

Location: http://docs.oracle.com/javaee/1.4/tutorial/doc/JMS.html

Getting started

Http://www.cnblogs.com/Macros/articles/361567.html