JMS Interview Questions and Answers

Ques 1. How many messaging models do JMS provide for and what are they?

Ans. JMS provide for two messaging models, publish-and-subscribe and point-to-point queuing.

Ques 2. What is JMS (Java Messaging Service)?

Ans. JMS is an acronym used for Java Messaging Service. It is Java's answer to creating software using asynchronous messaging. It is one of the official specifications of the J2EE technologies and is a key technology.

Ques 3. How the JMS is different from RPC?

Ans. In RPC the method invoker waits for the method to finish execution and return the control back to the invoker. Thus it is completely synchronous in nature. While in JMS the message sender just sends the message to the destination and continues it's own processing. The sender does not wait for the receiver to respond. This is asynchronous behavior.

Ques 4. What are the basic advantages of JMS?

Ans. JMS is asynchronous in nature. Thus not all the pieces need to be up all the time for the application to function as a whole. Even if the receiver is down the MOM will store the messages on it's behalf and will send them once it comes back up. Thus at least a part of application can still function as there is no blocking.

Ques 5. What are the different types of messages available in the JMS API?

Ans. Message, TextMessage, BytesMessage, StreamMessage, ObjectMessage, MapMessage are the different messages available in the JMS API.