Frequently Asked Questions of Java Message Service (JMS) framework

Frequently Asked Questions of Java Message Service (JMS) framework The Java message service (JMS) framework is an important tool for building a distributed application.It provides a message -based communication model that allows asynchronous transmission of messages and processing communication between messages.When using the JMS framework, you may encounter some common questions. The following are some common questions. Question 1: How to use the JMS framework in Java to send messages? To send JMS messages in Java, you need to use the following steps in JMS API: 1. Create an object connected to the factory, which will be responsible for creating a connection connected to the message agent. ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(); 2. Create a connection object and use the connection to the factory to establish a connection with the message agent. Connection connection = connectionFactory.createConnection(); 3. Create a session object for sending and receiving messages. Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); 4. Create a message publisher and specify the goal (queue or theme) to send messages. Destination destination = session.createQueue("your_queue_name"); MessageProducer producer = session.createProducer(destination); 5. Create a message object and send the message to the target. TextMessage message = session.createTextMessage("Hello, JMS!"); producer.send(message); 6. Close session, connection and publisher. producer.close(); session.close(); connection.close(); Question 2: How to use the JMS framework in Java to receive messages? To receive JMS messages in Java, you need to use the following steps in JMS API: 1. Create an object connected to the factory, which will be responsible for creating a connection connected to the message agent. ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(); 2. Create a connection object and use the connection to the factory to establish a connection with the message agent. Connection connection = connectionFactory.createConnection(); 3. Create a session object for sending and receiving messages. Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE); 4. Create a message consumer and subscribe to the target (queue or theme) to receive the message. Destination destination = session.createQueue("your_queue_name"); MessageConsumer consumer = session.createConsumer(destination); 5. Through the message monitor interface, the corresponding processing logic is triggered when the message arrives. consumer.setMessageListener(new MessageListener() { public void onMessage(Message message) { // Process the receiving message } }); 6. Start the connection to start the message monitoring. connection.start(); Question 3: How to deal with message confirmation and transaction processing of the JMS framework? The JMS framework provides two message confirmation modes: automatic confirmation (Auto_acknowledge) and client_acknowledge. -Auto_acknowledge: When the message consumers successfully receive the message from the JMS server, the message will automatically confirm.This is the default confirmation mode. -Client_acknowledge: Message Consumers must clearly call the method of `Message.acknowledge () to confirm the receiving message. When dealing with transactions, you can use the following steps: 1. When creating a session, set the first parameter to `true` to enable the transaction mode. Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE); 2. When you receive or send one or more messages, they will line up in the context of affairs. 3. If everything is normal, you can submit the transaction by calling the method of calling `session.commit ()`, and mark all the processed messages as confirmed. session.commit(); 4. If an error occurs or needs to be revoked, please call the method of `session.rollback () to return all the messages that have not been confirmed to the queue. session.rollback(); Question 4: How to use the JMS framework to process the durability and non -persistence of messages? The JMS framework supports marking the message as persistent or non -persistent.The persistent message is durable to the disk when sending, and can be passed after the message agent is restarted. To send persistent messages, set the `DeliveryMode` to` DeliveryMode.persisteent` when creating a message producer. producer.setDeliveryMode(DeliveryMode.PERSISTENT); To send non -persistent messages, set the `deliverymode` to` deliverymode.non_persistent`. producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT); Of course, to receive persistent news correctly, sources must correctly set the durability and identifier of subscribing.This is beyond the scope of this article, please refer to the document of the JMS framework to obtain more detailed information. In summary, we answered some common questions and introduced how to send and receive messages in JMS frameworks in Java, as well as the confirmation, transaction, durability and non -persistence of processing messages.I hope these answers can help you better understand and use the JMS framework.