How it works: IBM MQ classes for JMS with CICS

For example, the application component can be an application client, a servlet, a JavaServer Page (JSP), an enterprise Java bean (EJB), or a message driven bean (MDB). In this type of communication, the application server container provides only low-level functions in support of messaging operations, such as connection pooling and thread management.

Java EE applications use MDBs to process messages asynchronously. An MDB acts as a JMS message listener and is implemented by an onMessage() method, which defines how a message is processed. An MDB is deployed in the EJB container of an application server. The precise way in which an MDB is configured depends on which application server you are using, but the configuration information must specify which queue manager to connect to, how to connect to the queue manager, which destination to monitor for messages, and the transactional behavior of the MDB. This information is then used by the EJB container. When a message satisfying the selection criteria of the MDB arrives at the specified destination, the EJB container uses IBM MQ classes for JMS to retrieve the message from the queue manager, and then delivers the message to the MDB by calling its onMessage() method.