JMS API interpretation of technical principles in the Java class library

JMS (Java Message Service) is an API (application interface) for application communication between the Java platform.Its emergence enables developers to easily realize the message transmission system and reduce the complexity of inter -system communication.The JMS API provides a set of interfaces that define the format and communication specifications, making the communication between different systems simple and reliable. The technical principles of JMS API mainly involve the following aspects: 1. Message model: JMS API is passed by message based on the release-subscription model and point-to-point model.Published-Subscribe Model allows message publishers to send messages to one or more subscribers, and point-to-point models are sent to a specific receiver. 2. JMS provider: JMS API does not directly implement the message transmission function, but is implemented through the JMS provider.JMS providers can be message middleware (such as Apache ActiveMQ, IBM WebSphere MQ, etc.), or it can also be the JMS message agent embedded in the Java application itself. 3. ConnectionFactory: The ConnectionFactory interface in JMS API is used to create a JMS connection.Through ConnectionFatch, applications can establish connections with JMS providers and create sessions and message transmission objects. 4. Connection and Session: Connection interface representatives and JMS providers are connected.The session interface is used to create messages, message producers and message consumers.Usually, one application can create multiple session, and each session can have multiple products and consumer.Session also provides functions such as transaction management and message confirmation. 5. Destination and MESSAGEPRODUCER: The destination of the Destination interface can be a queue (queue) or topic.MESSAGEPRODUCER interface is used to send messages to specific Destinations. 6. MessageConsumer: MESSAGECONSUMER interface is used to receive messages.You can receive the message asynchronous by setting a message monitor (MESSAGELISTENER), or use the synchronization method for receiving. Here are some examples of Java code used by JMS API: 1. Create a connection and session: // Create ConnectionFactory ConnectionFactory factory = new ActiveMQConnectionFactory("tcp://localhost:61616"); // Create Connection and Session Connection connection = factory.createConnection(); Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); 2. Create messages and message producers: // Create message Destination (can be queue or topic) Destination destination = session.createQueue("myQueue"); // Create message producers MessageProducer producer = session.createProducer(destination); // Create messages TextMessage message = session.createTextMessage("Hello, JMS!"); // Send a message producer.send(message); 3. Create message Consumers and setting message monitor: // Create message Consumers MessageConsumer consumer = session.createConsumer(destination); // Set message monitor consumer.setMessageListener(new MessageListener() { public void onMessage(Message message) { try { if (message instanceof TextMessage) { TextMessage textMessage = (TextMessage) message; System.out.println("Received message: " + textMessage.getText()); } } catch (JMSException e) { e.printStackTrace(); } } }); Through the above code example, we can see the JMS API usage.It provides a series of interfaces and classes. Through these interfaces and classes, we can easily create JMS connections, send and receive messages, and process transactions and message confirmation.This enables developers to build reliable distributed applications more easily.