RabbitMQ 的核心概念

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
 
public class MessageProducer {
    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 使用默认交换机 以队列名作为 routing key
        String queueName = "msg_queue";
 
        /**
         * deliverMode 设置为 2 的时候代表持久化消息
         * expiration 意思是设置消息的有效期，超过10秒没有被消费者接收后会被自动删除
         * headers 自定义的一些属性
         * */
        //5. 发送
        Map<String, Object> headers = new HashMap<String, Object>();
        headers.put("myhead1", "111");
        headers.put("myhead2", "222");
 
        AMQP.BasicProperties properties = new AMQP.BasicProperties().builder()
                .deliveryMode(2)
                .contentEncoding("UTF-8")
                .expiration("100000")
                .headers(headers)
                .build();
        String msg = "test message";
        channel.basicPublish("", queueName, properties, msg.getBytes());
        System.out.println("Send message : " + msg);
 
        //6. 关闭连接
        channel.close();
        connection.close();
 
    }
}

import com.rabbitmq.client.*;
import java.io.IOException;
import java.util.Map;
 
public class MessageConsumer {
    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");
        factory.setAutomaticRecoveryEnabled(true);
        factory.setNetworkRecoveryInterval(3000);
 
        //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
        String queueName = "msg_queue";
        channel.queueDeclare(queueName, false, false, false, null);
 
        //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");
                Map<String, Object> headers = properties.getHeaders();
                System.out.println("head: " + headers.get("myhead1"));
                System.out.println(" [x] Received '" + message + "'");
                System.out.println("expiration : "+ properties.getExpiration());
            }
        };
 
        //6. 设置 Channel 消费者绑定队列
        channel.basicConsume(queueName, true, consumer);
    }
}

Send message : test message
 
head: 111
 [x] Received 'test message'
100000

/**
* Declare an exchange, via an interface that allows the complete set of
* arguments.
* @see com.rabbitmq.client.AMQP.Exchange.Declare
* @see com.rabbitmq.client.AMQP.Exchange.DeclareOk
* @param exchange the name of the exchange
* @param type the exchange type
* @param durable true if we are declaring a durable exchange (the exchange will survive a server restart)
* @param autoDelete true if the server should delete the exchange when it is no longer in use
* @param internal true if the exchange is internal, i.e. can't be directly
* published to by a client.
* @param arguments other properties (construction arguments) for the exchange
* @return a declaration-confirm method to indicate the exchange was successfully declared
* @throws java.io.IOException if an error is encountered
*/
Exchange.DeclareOk exchangeDeclare(String exchange,
                                 String type,boolean durable,
                                 boolean autoDelete,boolean internal,
                                 Map<String, Object> arguments) throws IOException;