Diagram of the J2EE application containing a web module and an EJB module. The modules are not directly connected. Instead, the web module sends messages to a queue managed by the application server. This is represented by arrows from the web module to the queue. The queue delivers messages to a message-driven bean in the EJB module. This is represented by an arrow from the queue to the message-driven bean. The interaction continues with an arrow between the message driven bean and a session bean, representing a method call. The session bean manages the processing of the message, which includes calls to other enterprise beans. This is represented in this diagram by an arrow connecting the session bean to an entity bean, which inserts data into a database.