What is Producer and Consumer?
A1: Messaging lets a servlet delegate processing to a batch process either on the same machine or on a separate machine. The servlet creates a message and sends it to a queue. The servlet immediately completes and when the batch process is ready, it processes the message. Messaging is therefore comprised of three main components: A Producer creates messages and sends them to a Queue. The Producer could be something like a Servlet. A Queue stores the messages from the Produces and provides them to a Consumer when ready. The Queue is implemented by the messaging provider. A Consumer processes messages as they become available in the Queue. The Consumer is typically a bean implementing the MessageListener interface. A2: A producer is the client application that plays the role of a message sender in JMS API. A consumer is the client application that plays the role of a message receiver in JMS API.