JMS (Java Message Service) framework and message middleware

JMS (Java Message Service) is a message transmission standard on the Java platform to achieve asynchronous communication in distributed systems.The message middle part is a software component or service used in distributed systems.This article will introduce the relationship between the JMS framework and the message middleware, and provide some Java code examples. 1. JMS framework overview JMS is part of the Java Enterprise Edition (Jee), which provides a set of API (Application Programming Interface) for sending, receiving and processing messages in a distributed system.It defines a standardized way that allows Java applications to communicate with message middleware. The main components of the JMS framework include the following roles: 1. Message Producer: Responsible for creating and sending messages to message middleware. 2. Message Consumer: Responsible for receiving and processing messages. 3. Destination: The location of the message sending and receiving can be a queue or topic. 4. Connection Factory: It is used to create a connection connected to the message middleware. 5. JMS provider (JMS Provider): Implement the JMS specification message middleware. 2. Overview of the message middleware The middle part of the message is a software component or service that conveys messages in a distributed system.As a transit station of the message, it is responsible for the routing, transmission and storage of the message.Message middleware has the following characteristics: 1. Asynchronous communication: Message intermediate parts support asynchronous communication mode, and the derivative and receiver are decoupled, which can operate independently. 2. Reliability: Message provides a reliable message transmission mechanism to ensure that the message can be transmitted safely and processed by the receiver. 3. Senior message: The message intermediate part can persist the message to the disk to prevent the message from being lost. Common messages include ActiveMQ, Rabbitmq, IBM MQ, etc. 3. The relationship between JMS and message middleware The JMS framework defines unified API and specifications, so that Java applications can communicate with different JMS providers.The message middleware is a software that implements the JMS specification, which provides the underlying message transmission and processing mechanism. When using JMS for message communication, the following steps need to be performed: 1. Create the connection factory object, which is used to create a connection connected to the message middleware. 2. Create a connection object and open the connection. 3. Create a session object, producer and consumers for creating messages. 4. Create destination objects to represent the sending and receiving location of the message. 5. Create a message producer object for sending messages to the destination. 6. Create a message consumer object for receiving and processing messages. 7. Send and receive messages. The following is a simple example code that demonstrates how to use the JMS framework with the ActiveMQ message intermediate parts to send and receive: import javax.jms.*; import org.apache.activemq.ActiveMQConnectionFactory; public class JMSExample { public static void main(String[] args) throws JMSException { // Create a connection factory ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616"); // Create a connection Connection connection = connectionFactory.createConnection(); connection.start(); // Create the meeting Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); // Create destinations Destination destination = session.createQueue("test.queue"); // Create message producers MessageProducer producer = session.createProducer(destination); // Create messages TextMessage message = session.createTextMessage("Hello, JMS!"); // Send a message producer.send(message); // Create message Consumers MessageConsumer consumer = session.createConsumer(destination); // Receive messages Message receivedMessage = consumer.receive(); if (receivedMessage instanceof TextMessage) { TextMessage textMessage = (TextMessage) receivedMessage; System.out.println("Received message: " + textMessage.getText()); } // Turn off the connection session.close(); connection.close(); } } In the above code, we use ActiveMQ as a message middleware and create a connection factory through ActiveMQConnectionFactory.Then, create related objects such as connection, session, destination, message producer, and message consumers, and send and receive messages.Finally, close the connection to release resources. Summarize: The JMS framework is a message transmission standard on the Java platform that is used to implement asynchronous communication in a distributed system.The message middleware is a software that implements the JMS specification, which provides the underlying message transmission and processing mechanism.Using the JMS framework can easily communicate with different message middleware to achieve message sending, receiving and processing.Through the example code, we can understand how the JMS framework is combined with the message middleware to achieve message communication in the distributed system.