RabbitMQ 消息中间件

RabbitMQ是用Erlang实现的一个高并发高可靠AMQP消息队列服务器。
支持消息的持久化、事务、拥塞控制、负载均衡等特性，使得RabbitMQ拥有更加广泛的应用场景。

场景1：单发送单接收 

使用场景：简单的发送与接收，没有特别的处理。

package com.qa.util;

import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class ConnectionUtil {

    private static ConnectionFactory factory;

    static{
        //连接rabbitmq服务器
        factory = new ConnectionFactory();
        factory.setHost("192.168.189.128");
        factory.setPort(5672);
        factory.setUsername("admin");
        factory.setPassword("admin");
        factory.setVirtualHost("/admin");
    }

    public static Connection getConnection(){
        Connection connection = null;
        try {
            connection = factory.newConnection();
            return connection;
        } catch (IOException e) {
            e.printStackTrace();
        } catch (TimeoutException e) {
            e.printStackTrace();
        }
        return null;
    }
}

public class Provider {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取通道Channel对象，后续所有的操作都是基于Channel实现
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("queue1",false,false,false,null);
        //给队列发送消息
        channel.basicPublish(
                "",
                "queue1",
                null,
                "Hello RabbitMQ".getBytes("utf-8"));
        //断开链接
        connection.close();
    }
}

public class Consumer {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //监听队列中的消息
        channel.basicConsume("queue1",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费端获得消息："+new String(body,"utf-8"));
            }
        });
    }
}

场景2：单发送多接收

使用场景：一个发送端，多个接收端，如分布式的任务派发。为了保证消息发送的可靠性，不丢失消息，使消息持久化了。同时为了防止接收端在处理消息时down掉，只有在消息处理完成后才发送ack消息。

public class Provider {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取通道Channel对象，后续所有的操作都是基于Channel实现
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("queue1",false,false,false,null);
        //给队列发送消息
        for (int i=1;i<=10;i++){
            channel.basicPublish(
                    "",
                    "queue1",
                    null,
                    ("Hello RabbitMQ"+i).getBytes("utf-8"));
        }
        //断开链接
        connection.close();
    }
}

public class Consumer {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //监听队列中的消息
        channel.basicConsume("queue1",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费端1获得消息："+new String(body,"utf-8"));
            }
        });
    }
}

public class Consumer2 {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //监听队列中的消息
        channel.basicConsume("queue1",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费端2获得消息："+new String(body,"utf-8"));
            }
        });
    }
}

场景3：Publish/Subscribe

使用场景：发布、订阅模式，发送端发送广播消息，多个接收端接收。

public class Provider {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取通道Channel对象，后续所有的操作都是基于Channel实现
        Channel channel = connection.createChannel();
        //创建交换机
        channel.exchangeDeclare("fanout_exchange","fanout");
        //给交换机发送消息
        for (int i=1;i<=10;i++){
            channel.basicPublish(
                    "fanout_exchange",
                    "",
                    null,
                    ("Hello RabbitMQ"+i).getBytes("utf-8"));
        }
        //断开链接
        connection.close();
    }
}

public class  Consumer {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("fanout_queue1",false,false,false,null);
        //绑定交换机
        channel.queueBind("fanout_queue1","fanout_exchange","");
        //监控队列
        channel.basicConsume("fanout_queue1",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者1获取消息："+new String(body,"utf-8"));
            }
        });
    }
}

public class Consumer2 {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("fanout_queue2",false,false,false,null);
        //绑定交换机
        channel.queueBind("fanout_queue2","fanout_exchange","");
        //监控队列
        channel.basicConsume("fanout_queue2",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者2获取消息："+new String(body,"utf-8"));
            }
        });
    }
}

场景4：Routing (按路线发送接收)

使用场景：发送端按routing key发送消息，不同的接收端按不同的routing key接收消息。

public class Provider {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取通道Channel对象，后续所有的操作都是基于Channel实现
        Channel channel = connection.createChannel();
        //创建交换机
        channel.exchangeDeclare("direct_exchange","direct");
        //给交换机发送消息
        for (int i=1;i<=10;i++){
            channel.basicPublish(
                    "direct_exchange",
                    "insert", //路由键（消费端绑定交换机对应的路由键为insert，才能监听到该消息）
                    null,
                    ("Hello RabbitMQ"+i).getBytes("utf-8"));
        }
        //断开链接
        connection.close();
    }
}

public class  Consumer {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("direct_queue1",false,false,false,null);
        //绑定交换机
        channel.queueBind("direct_queue1","direct_exchange","select"); //路由键
        //监控队列
        channel.basicConsume("direct_queue1",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者1获取消息："+new String(body,"utf-8"));
            }
        });
    }
}

public class Consumer2 {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("direct_queue2",false,false,false,null);
        //绑定交换机
        channel.queueBind("direct_queue2","direct_exchange","select"); //路由键
        channel.queueBind("direct_queue2","direct_exchange","insert");
        //监控队列
        channel.basicConsume("direct_queue2",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者2获取消息："+new String(body,"utf-8"));
            }
        });
    }
}

场景5：Topics (按topic发送接收)

使用场景：发送端不只按固定的routing key发送消息，而是按字符串“匹配”发送，接收端同样如此。

public class Provider {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取通道Channel对象，后续所有的操作都是基于Channel实现
        Channel channel = connection.createChannel();
        //创建交换机
        channel.exchangeDeclare("topic_exchange","topic");
        //给交换机发送消息
        for (int i=1;i<=10;i++){
            channel.basicPublish(
                    "direct_exchange",
                    "emp.hello", //路由键
                    null,
                    ("Hello RabbitMQ"+i).getBytes("utf-8"));
        }
        //断开链接
        connection.close();
    }
}

public class  Consumer {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("topic_queue1",false,false,false,null);
        //绑定交换机
        channel.queueBind("topic_queue1","topic_exchange","emp.#"); //emp.# 路由键
        //监控队列
        channel.basicConsume("topic_queue1",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者1获取消息："+new String(body,"utf-8"));
            }
        });
    }
}

public class Consumer2 {
    public static void main(String[] args) throws Exception {
        Connection connection =  ConnectionUtil.getConnection();
        //获取Channel对象
        Channel channel = connection.createChannel();
        //创建队列
        channel.queueDeclare("topic_queue2",false,false,false,null);
        //绑定交换机
        channel.queueBind("topic_queue2","topic_exchange","emp.*"); //emp.* 路由键
        //监控队列
        channel.basicConsume("topic_queue2",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消费者2获取消息："+new String(body,"utf-8"));
            }
        });
    }
}

SpringBoot整合RabbitMQ: https://www.cnblogs.com/wakey/p/10701454.html