JAVA MESSAGE SERVICE – JMS

Techno Kryon

JMS Introduction:-

            Java Message Service (JMS) is an Application Programming Interface (API) that provides the facility to create, send, receive and read messages.

              Java Message service provides asynchronous communication, loosely coupled and reliable. It is also known as messaging service in java.

              The Java Message Service (JMS) API is a message-oriented middleware API for sending messages between two or more clients. JMS is mainly used for sending and receiving a message from one application to another application.

            JMS is a part of the Java Platform, Java Enterprise Edition developed at Sun Microsystems, but which has been guided by the Java Community Process.

 JMS Messaging Domains:-

                 Java Message Service has two types of messaging domains.

·         Point-to-Point Messaging Domain

·         Publisher/Subscriber Messaging Domain

Point-to-Point Messaging Domain:-

                In PTP, messages are delivered to individual consumers (only one receiving consumer) and who maintain Queues of incoming message system. This PTP messaging Concept implements for message Queues, senders and receivers. It is also Works as First in First out (FIFO) like a stack.

                In PTP, any number of message or producers can send messages to the queue, each message delivered to only one consumer and each message is guaranteed to be delivered. Queues retain all messages sent to them until the messages expire or consumed. If no consumers are registered to deliver the messages, the queue waits for them until a consumer registered and message delivered to the registered consumer. There is no time dependency between consumer and Publisher/Subscriber and also receiver acknowledged the consumption on each message in JMS.

Publisher/Subscriber Messaging Domain:-

                   Publish-Subscribe messaging model, one message is delivered to all subscribers like broadcasting message technique.  In this model, Topic is used as a Java message-oriented middle ware that is responsible to wait and delivered the messages to subscribers.

·         Zero or more consumers will receive the message in this publisher messaging domain.

·         There is a timing dependency between Sender and Receiver. The publisher has created the message topic for clients to subscribe. The subscriber must remain active continuously to receive messages unless it has established a durable time.         

               Applications do not need to be on the same server because of loosely coupled. Message communication techniques are handled by the message broker, it is called a topic and each message is guaranteed to be delivered and each receiver acknowledged the consumption of each message in JMS.

                A message can have delivery to multiple consumers and consumers will get the messages after consumers get subscribed and consumers need to wait for continuously in order to get new messages.

Advantage for JMS:-

·         Asynchronous Communication - JMS of point-to-point messaging domain queue provides high throughput, high performance due to asynchronous behavior. JMS has the capability to send thousands of messages within a second to concurrent consumers using multiple threads and processes.

·         Reliability – Message sent will surely to be delivered for consumers without any loss of data. Also, the message will be sent only once in JMS.

·         Load Balancing – When there is increase the load in JMS. The lots of messages are received by consumers, and then the JMS does efficient load balancing by having a pool of message processors.