一个最简单的消息队列，带你理解 RabbitMQ！

package com.anqi.mq.nat;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class MyProducer {
    private static final String QUEUE_NAME = "ITEM_QUEUE";
    public static void main(String[] args) throws Exception {
        //1. 创建一个 ConnectionFactory 并进行设置
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setVirtualHost("/");
        factory.setUsername("guest");
        factory.setPassword("guest");
        //2. 通过连接工厂来创建连接
        Connection connection = factory.newConnection();
        //3. 通过 Connection 来创建 Channel
        Channel channel = connection.createChannel();
        //实际场景中，消息多为json格式的对象
        String msg = "hello";
        //4. 发送三条数据
        for (int i = 1; i <= 3 ; i++) {
            channel.basicPublish("", QUEUE_NAME, null, msg.getBytes());
            System.out.println("Send message" + i +" : " + msg);
        }
        //5. 关闭连接
        channel.close();
        connection.close();
    }
}
/**
 * Declare a queue
 * @param queue the name of the queue
 * @param durable true if we are declaring a durable queue (the queue will survive a server restart)
 * @param exclusive true if we are declaring an exclusive queue (restricted to this connection)
 * @param autoDelete true if we are declaring an autodelete queue (server will delete it when no longer in use)
 * @param arguments other properties (construction arguments) for the queue
 * @return a declaration-confirm method to indicate the queue was successfully declared
 * @throws java.io.IOException if an error is encountered
 */
Queue.DeclareOk queueDeclare(String queue, boolean durable, boolean exclusive, boolean autoDelete,Map<String, Object> arguments) throws IOException;
/**
 * Publish a message
 * @see com.rabbitmq.client.AMQP.Basic.Publish
 * @param exchange the exchange to publish the message to
 * @param routingKey the routing key
 * @param props other properties for the message - routing headers etc
 * @param body the message body
 * @throws java.io.IOException if an error is encountered
 */
void basicPublish(String exchange, String routingKey, BasicProperties props, byte[] body) throws IOException;
/**
 * Start a non-nolocal, non-exclusive consumer, with
 * a server-generated consumerTag.
 * @param queue the name of the queue
 * @param autoAck true if the server should consider messages
 * acknowledged once delivered; false if the server should expect
 * explicit acknowledgements
 * @param callback an interface to the consumer object
 * @return the consumerTag generated by the server
 * @throws java.io.IOException if an error is encountered
 * @see com.rabbitmq.client.AMQP.Basic.Consume
 * @see com.rabbitmq.client.AMQP.Basic.ConsumeOk
 * @see #basicConsume(String, boolean, String, boolean, boolean, Map, Consumer)
 */
String basicConsume(String queue, boolean autoAck, Consumer callback) throws IOException;

package com.anqi.mq.nat;
import com.rabbitmq.client.*;
import java.io.IOException;
public class MyConsumer {
    private static final String QUEUE_NAME = "ITEM_QUEUE";
    public static void main(String[] args) throws Exception {
        //1. 创建一个 ConnectionFactory 并进行设置
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setVirtualHost("/");
        factory.setUsername("guest");
        factory.setPassword("guest");
        //2. 通过连接工厂来创建连接
        Connection connection = factory.newConnection();
        //3. 通过 Connection 来创建 Channel
        Channel channel = connection.createChannel();
        //4. 声明一个队列
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
        /*
           true:表示自动确认，只要消息从队列中获取，无论消费者获取到消息后是否成功消费，都会认为消息已经成功消费
           false:表示手动确认，消费者获取消息后，服务器会将该消息标记为不可用状态，等待消费者的反馈，如果消费者一
           直没有反馈，那么该消息将一直处于不可用状态，并且服务器会认为该消费者已经挂掉，不会再给其发送消息，
           直到该消费者反馈。
        */
        //5. 创建消费者并接收消息
        Consumer consumer = new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope,
                                       AMQP.BasicProperties properties, byte[] body)
                    throws IOException {
                String message = new String(body, "UTF-8");
                System.out.println(" [x] Received '" + message + "'");
            }
        };
        //6. 设置 Channel 消费者绑定队列
        channel.basicConsume(QUEUE_NAME, true, consumer);
    }
}
Send message1 : hello
Send message2 : hello
Send message3 : hello
 [*] Waiting for messages. To exit press CTRL+C
 [x] Received 'hello'
 [x] Received 'hello'
 [x] Received 'hello'