JMS - Enterprise Messaging Systems

Description

An enterprise messaging system is frequently called as message oriented middleware (MOM) to combine the applications in a flexible way. The MOM acts as mediator between two applications to communicate with each other.

Messaging Flexibility

The messaging flexibility can be explained as shown in the figure below −

In the above figure, you can see that, Application One communicates with Application Two by using Enterprise Messaging System and sends message via Application Programming Interface (API). The Enterprise Messaging System sends the message to Application Two which is present on different system by handling the network communications. The messaging system will forward the message to Application Two, if there is a network connection; otherwise it will store the message until the connection becomes available, and then send it to Application Two.

Loose Coupling

It is a process of connecting the components of a system by reducing the inter dependencies between them. Loose Coupling increases the flexibility of system and makes the application more maintainable and stable.

JMS is a standard Java interface for enterprise messaging system and it is widely used technology for loosely coupled systems, which are executed in Java.

Publish and Subscribe Message

The publish/subscribe message approach includes multiple publishers and multiple consumers in which one message will be sent to all clients. Here, both publishers and subscribers are generally unknown and they will have timing dependencies

For more information on publish/subscribe message approach, refer this chapter.