Java Ee JMS API in Java Class Library
Java Ee JMS API basic knowledge
Java Ee (Java Enterprise Edition) is a Java platform for building an enterprise -level application.JMS (Java Message Service) is part of Java Ee, which provides a standardized message transmission mechanism for asynchronous communication in a distributed computing environment.This article will introduce the basic knowledge of the Java Ee JMS API, including an overview of JMS, JMS message model, JMS character and component, JMS message transmission mode, and Java code examples.
JMS Overview:
JMS is a Java API for creating, sending and receiving messages.It provides a reliable asynchronous communication mechanism that enables each application to communicate in the form of messages.JMS allows applications not to wait for the receiver's response when sending messages, thereby improving the performance and scalability of the system.
JMS message model:
The JMS message model consists of two basic concepts: producers and consumers.The producer is the founder and sender of the message, and the consumer is the receiver of the message.The message is passed through the message transmission mode provided by the producer and consumers.
JMS characters and components:
In JMS, there are four common characters: message producers, news consumers, news destinations and factories.
-A message producer is responsible for creating and sending messages to news destinations.
-A message consumers are responsible for receiving and processing messages from the news destination.
-Se a message destination is the end of the message transmission, which can be queue or topic.
-The factory is an object used to create a JMS connection, which can configure parameters connected, such as URL, username and password.
JMS message transfer mode:
JMS defines two message transmission modes: Point-To-Point and Publish/Subscribe.
-In the point -to -point mode, the message producer sends the message to the target queue, and the message consumers receive the message from the queue.Each message can only be accepted by one consumer.
-In the release/subscription mode, the message producer sends the message to the target theme, and all consumers who subscribe to the theme can receive the message.Each message can be received by multiple consumers.
Here are some examples of Java code. It demonstrates how to send and receive messages using the Java Ee JMS API:
1. Create a connection factory:
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.QueueConnectionFactory;
import javax.jms.TopicConnectionFactory;
import org.apache.activemq.ActiveMQConnectionFactory;
// Create queue connection factory
QueueConnectionFactory queueConnectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
// Create the theme connection factory
TopicConnectionFactory topicConnectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
2. Create message producers:
import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Session;
// Create queue connection
Connection connection = queueConnectionFactory.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
// Create queue
Destination queue = session.createQueue("TestQueue");
// Create message producers
MessageProducer producer = session.createProducer(queue);
3. Send message:
import javax.jms.JMSException;
import javax.jms.TextMessage;
// Create text messages
TextMessage message = session.createTextMessage("Hello, JMS!");
// Send a message
producer.send(message);
4. Create message Consumers:
import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.Session;
// Create queue connection
Connection connection = queueConnectionFactory.createConnection();
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
// Create queue
Destination queue = session.createQueue("TestQueue");
// Create message Consumers
MessageConsumer consumer = session.createConsumer(queue);
5. Receive message:
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.TextMessage;
// Receive messages
Message receivedMessage = consumer.receive();
// Treatment text messages
if (receivedMessage instanceof TextMessage) {
TextMessage textMessage = (TextMessage) receivedMessage;
String messageText = textMessage.getText();
System.out.println("Received Message: " + messageText);
}
The above is a brief introduction to the basic knowledge of Java Ee JMS API and code examples.By using JMS, developers can easily realize message transmission and asynchronous communication, and build reliable and high -performance enterprise -level applications.
