The technical principle of message drive in the Javaee API framework

The technical principle of message drive in the Javaee API framework Message driver is an important technology in the Javaee API framework to achieve asynchronous processing and dynamic coupling.It is based on the release-subscription mode, and uses the message queue to realize the transmission and processing of messages.This article will introduce the technical principles of message -driven and provide some examples of Java code. 1. Basic concept of message drive Message driver is a decoupling method. It can separate the message of the message by separating the sending and processing of the message, so that different modules of the system can work independently.In a message -driven mode, the sender of the message publishes the message to the message queue, and the receiver of the message subscribe and process the message from the message queue. 2. Message queue The core of the message drive is the message queue, which is a middleware that is used to store messages and realize the transmission of messages.The message queue can guarantee the reliable transmission of the message, even if the message sends and the receiver are online at different times.Common message queues include ActiveMQ, Rabbitmq, and Kafka. 3. Message -driven API Javaee provides a set of APIs to achieve message drive.The most important one is the Java MesSage Service (JMS) API.JMS is a standard Java message middleware API, which defines interfaces and classes for sending, receiving and managing messages.JMS provides a variety of message models, including the point-to-point model (Queue) and release-subscription model (Topic). 4. Sending and receiving message In a message -driven mode, the sender of the message publishes the message into the message queue through creating a message object.Senders can choose to send or send messages synchronously or asynchronous.The example code is as follows: // Create a JMS connection and session ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(); Connection connection = connectionFactory.createConnection(); Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); // Create a message queue Queue queue = session.createQueue("myQueue"); // Create a message sender and send messages MessageProducer producer = session.createProducer(queue); TextMessage message = session.createTextMessage("Hello, world!"); producer.send(message); // Turn off the connection and session producer.close(); session.close(); connection.close(); The receiver of the message is subscribed and received from the message queue by creating a message monitor.The listener implements the MESSAGELISTER interface of JMS and implements the onMessage () method to process the received messages.The example code is as follows: // Create a JMS connection and session ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(); Connection connection = connectionFactory.createConnection(); Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); // Create a message queue Queue queue = session.createQueue("myQueue"); // Create a message receiver and register a message monitor MessageConsumer consumer = session.createConsumer(queue); consumer.setMessageListener(new MessageListener() { @Override public void onMessage(Message message) { try { if (message instanceof TextMessage) { TextMessage textMessage = (TextMessage) message; String text = textMessage.getText(); System.out.println("Received message: " + text); } } catch (JMSException e) { e.printStackTrace(); } } }); // Start the connection connection.start(); 5. The advantages and application scenarios of message drive Message -driven mode has the following advantages: -Couple: By separating the sending and processing of messages, the coupling degree between each module is reduced. -D asynchronous processing: Message driver is an asynchronous mode that can improve the concurrent performance of the system. -Connens: The message queue can guarantee the reliability of the message, even if the message sending and the receiver are online at different times. Message driver is suitable for the following scenes: -D asynchronous processing: When the system needs to handle a large number of concurrent tasks, you can use message drive to achieve asynchronous processing. -Pulation application: When the system of each module needs to be decoupled, a message drive can be used to implement communication between modules. Summarize This article introduces the technical principles of message -driven in the Javaee API framework.The message driver is separated by the separation and processing of the message, and the system is not asynchronous and tone.JMS is the core API that implements message -driven in Javaee API, which provides functions such as sending, receiving and management of message sending, receiving and management.By using the message queue, the message driver can achieve reliable message transmission.