What is Java Message Service (JMS) for?

Question

I am currently evaluating JMS and I don\'t get what I could use it for.

Currently, I believe this would be a Usecase: I want to create a SalesInvoice PDF and print it w

Answer 1

From the Javadoc:

The Java Message Service (JMS) API provides a common way for Java programs to create, send, receive and read an enterprise messaging system's messages.

In other words, and contrary to every other answer here, JMS is nothing more than an API, which wraps access to third-party Message Brokers, via 'JMS Providers' implemented by the vendor. Those Message Brokers, such as IBM MQ and dozens of others, have the features of reliability, asynchronicity, etc. that have been mentioned in other answers. JMS itself provides exactly none of them. It is to Message Brokers what JDBC is to SQL databases, or JNDI is to LDAP servers (among other things).