After connecting to a message queue or topic, three operations may be executed on the queue or topic:

  • Sending a message,

  • receiving a message,

  • or listening to messages.

The JMS adapter can receive a message from a JMS provider in two ways: the JMS adapter registers the JMS port type as a listener on the JMS provider’s queue and the JMS provider calls the JMS adapter when a message is available on the queue, or the JMS adapter accesses the JMS provider’s queue on demand.

The sending and receiving of messages is done by JMS adapter action nodes with a specific action (send or receive) and specific parameters.

The listening to a topic is implemented by listener operations, which are part of the central class JMSListener (stereotype <<E2EJMSListener>>) in the xUML service template.