• RabbitMQ In JAVA 介绍及使用


    介绍:

      RabbitMQ是开源的消息中间件,它是轻量级的,支持多种消息传递协议,可以部署在分布式和联合配置中,以满足高级别、高可用性需求。并且可在许多操作系统和云环境上运行,并为大多数流行语言提供了广泛的开发工具。(这里只介绍JAVA下的RabbitMQ的使用,感兴趣的可以查看官方文档:http://www.rabbitmq.com/getstarted.html);

    安装:

      参考:http://www.cnblogs.com/lfalex0831/p/8951955.html(windows安装)

    应用场景:

      1、异步处理,主要为了较少请求的响应时间和解耦。即将比较耗时又不需要同步的操作放入消息队列中进行传递请求,只要保证消息格式(可以理解为接头的暗号)不变,这样消息的发送方和接收方互不干扰交互,即为解耦;

      2、广播,顾名思义,广播的好处就是一次发送,大家共享,大大的减少了冗余的操作,也降低了新增消费者的成本;

      3、流量削峰,比如秒杀活动,因为流量过大,导致应用挂掉,为了避免这个问题,会在应用前端加入消息队列。 
      作用: 
        1.可以控制进入后台的服务,超过阀值的订单直接丢弃;
        2.可以缓解瞬时的高流量压垮应用;

      ps:秒杀系统优化思路可以从将请求尽量拦截在系统上游充分利用缓存;

      (如果还有别的应用场景,请大家多多指教。。。)

    使用场景(本文使用的RabbitMQ的版本为5.20版本):

    This tutorial assumes RabbitMQ is installed and running on localhost on standard port (5672). In case you use a different host, port or credentials, connections settings would require adjusting.

     注意:根据官方文档说明,RabbitMQ的默认访问端口为5672,而管理端口为15672,希望不要搞混了(我刚接触时就没注意,果断乱了。。-_-||)。

      基本概念:

    • Broker:简单来说就是消息队列服务器实体
    • Exchange:消息交换机,它指定消息按什么规则,路由到哪个队列
    • Queue:消息队列载体,每个消息都会被投入到一个或多个队列
    • Binding:绑定,它的作用就是把exchange和queue按照路由规则绑定起来
    • Routing Key:路由关键字,exchange根据这个关键字进行消息投递
    • vhost:虚拟主机,一个broker里可以开设多个vhost,用作不同用户的权限分离
    • producer:消息生产者,就是投递消息的程序
    • consumer:消息消费者,就是接受消息的程序
    • channel:消息通道,在客户端的每个连接里,可建立多个channel,每个channel代表一个会话任务

      1、简单使用(HelloWorld)

      在下图中,P是我们的生产者,C是我们的消费者。中间的框是一个队列——RabbitMQ代表消费者保存的消息缓冲区。

       

      创建RabbitMQ的工厂类:

     1 import com.rabbitmq.client.Connection;
     2 import com.rabbitmq.client.ConnectionFactory;
     3 import java.io.IOException;
     4 import java.util.concurrent.TimeoutException;
     5 
     6 public class ConnectionUtil {
     7 
     8     private static final String RABBIT_HOST = "localhost";
     9 
    10     private static final String RABBIT_USERNAME = "guest";
    11 
    12     private static final String RABBIT_PASSWORD = "guest";
    13 
    14     private static Connection connection = null;
    15 
    16     public static Connection getConnection() {
    17         if(connection == null) {
    18             ConnectionFactory connectionFactory = new ConnectionFactory();
    19             connectionFactory.setHost(RABBIT_HOST);
    20             connectionFactory.setUsername(RABBIT_USERNAME);
    21             connectionFactory.setPassword(RABBIT_PASSWORD);
    22             try {
    23                 connection = connectionFactory.newConnection();
    24             } catch (IOException e) {
    25                 e.printStackTrace();
    26             } catch (TimeoutException e) {
    27                 e.printStackTrace();
    28             }
    29         }
    30         return connection;
    31     }
    32 
    33 }
    ConnectionUtil.java

       创建生产者Producer:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.Channel;
     3 import com.rabbitmq.client.Connection;
     4 import java.io.IOException;
     5 import java.util.concurrent.TimeoutException;
     6 
     7 public class Producer {
     8 
     9     private static final String QUEUE_NAME="test_queue";
    10 
    11     public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
    12         //获取连接
    13         Connection connection = ConnectionUtil.getConnection();
    14         System.out.println(connection);
    15         //创建通道
    16         Channel channel = connection.createChannel(1);
    17         /*
    18          * 声明(创建)队列
    19          * 参数1:队列名称
    20          * 参数2:为true时server重启队列不会消失
    21          * 参数3:队列是否是独占的,如果为true只能被一个connection使用,其他连接建立时会抛出异常
    22          * 参数4:队列不再使用时是否自动删除(没有连接,并且没有未处理的消息)
    23          * 参数5:建立队列时的其他参数
    24          */
    25         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    26         String message = "Hello World!";
    27         for (int i = 0; i < 20; i++) {
    28             message = message + i;
    29             channel.basicPublish("",QUEUE_NAME,null,message.getBytes());
    30             Thread.sleep(1000);
    31         }
    32         System.out.println("生产者 send :"+message);
    33         channel.close();
    34         connection.close();
    35     }
    36 
    37 }
    Producer.java

      创建消费者Consumer:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.DefaultConsumer;
     6 import com.rabbitmq.client.Envelope;
     7 import java.io.IOException;
     8 
     9 public class Consumer {
    10 
    11     private static final String QUEUE_NAME = "test_queue";
    12 
    13     public static void main(String[] args) throws IOException {
    14         Connection connection = ConnectionUtil.getConnection();
    15         Channel channel = connection.createChannel(1);
    16         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    17         StringBuffer message = new StringBuffer();
    18         //自4.0+ 版本后无法再使用QueueingConsumer,而官方推荐使用DefaultConsumer
    19         com.rabbitmq.client.Consumer consumer = new DefaultConsumer(channel) {
    20             @Override
    21             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    22                 throws IOException {
    23                 try {
    24                     Thread.sleep(2000);
    25                 } catch (InterruptedException e) {
    26                     e.printStackTrace();
    27                 }
    28                 super.handleDelivery(consumerTag, envelope, properties, body);
    29                 message.append(new String(body,"UTF-8"));
    30                 System.out.println(new String(body,"UTF-8"));
    31             }
    32         };
    33         //监听队列,当b为true时,为自动提交(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息,都认为是消息已经成功消费),
    34         // 当b为false时,为手动提交(消费者从队列中获取消息后,服务器会将该消息标记为不可用状态,等待消费者的反馈,
    35         // 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。
    36         //如果选用自动确认,在消费者拿走消息执行过程中出现宕机时,消息可能就会丢失!!)
    37         //使用channel.basicAck(envelope.getDeliveryTag(),false);进行消息确认
    38         channel.basicConsume(QUEUE_NAME,true,consumer);
    39         System.out.println(message.toString());
    40     }
    41 }
    Consumer.java

      测试结果,Consumer收到Producer的消息。

      2、Work Queue

      上一个例子是一对一发送接收形式,而工作队列为一对多发送接收形式。工作队列(即任务队列)背后的主要思想是避免立即执行资源密集型任务,并且必须等待它完成。相反,我们把任务安排在以后做。我们将任务封装为消息并将其发送到队列。在后台运行的工作进程会弹出任务并最终执行任务。当你运行许多Consumer时,任务将在他们之间共享,如下图:

       

      由于工厂类已经创建,直接使用即可。

      创建生产者Producer:

    package com.cn.work;
    
    import com.cn.ConnectionUtil;
    import com.rabbitmq.client.Channel;
    import com.rabbitmq.client.Connection;
    
    /**
     * @program: rabbit-learn
     * @description: 生产者
     * @create: 2018-04-26 16:18
     **/
    public class Producer {
    
        private final static String QUEUE_NAME = "test_queue_work";
    
        public static void main(String[] args) throws Exception {
            Connection connection = ConnectionUtil.getConnection();
            Channel channel = connection.createChannel();
            channel.queueDeclare(QUEUE_NAME,false,false,false,null);
            for (int i = 0; i < 50; i++) {
                String message = "" + i;
                channel.basicPublish("",QUEUE_NAME,null,message.getBytes());
                Thread.sleep(100 * i);
            }
            channel.close();
            connection.close();
        }
    
    }
    Producer.java

      创建消费者1,2:

    import com.cn.ConnectionUtil;
    import com.rabbitmq.client.AMQP.BasicProperties;
    import com.rabbitmq.client.Channel;
    import com.rabbitmq.client.Connection;
    import com.rabbitmq.client.Consumer;
    import com.rabbitmq.client.DefaultConsumer;
    import com.rabbitmq.client.Envelope;
    import java.io.IOException;
    
    public class Consumer1 {
    
        private final static String QUEUE_NAME = "test_queue_work";
    
        public static void main(String[] args) throws IOException {
            Connection connection = ConnectionUtil.getConnection();
            Channel channel = connection.createChannel();
            channel.basicQos(1);//能者多劳模式
            //声明队列
            channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    
            //自4.0+ 版本后无法再使用QueueingConsumer,而官方推荐使用DefaultConsumer
            Consumer consumer = new DefaultConsumer(channel) {
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
                    throws IOException {
                    super.handleDelivery(consumerTag, envelope, properties, body);
                    String message = new String(body,"UTF-8");
                    System.out.println(message);
                    try {
                        Thread.sleep(10);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    try {
                        doWork(message);
                    }finally {
                        channel.basicAck(envelope.getDeliveryTag(),false);
                    }
                }
            };
            //监听队列,当b为true时,为自动提交(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息,都认为是消息已经成功消费),
            // 当b为false时,为手动提交(消费者从队列中获取消息后,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。
            //如果选用自动确认,在消费者拿走消息执行过程中出现宕机时,消息可能就会丢失!!)
            //使用channel.basicAck(envelope.getDeliveryTag(),false);进行消息确认
            channel.basicConsume(QUEUE_NAME,false,consumer);
        }
    
        private static void doWork(String task) {
            for (char ch : task.toCharArray()) {
                if (ch == '.') {
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException _ignored) {
                        Thread.currentThread().interrupt();
                    }
                }
            }
        }
    
    }
    Consumer1.java
     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 import java.io.IOException;
     9 
    10 public class Consumer2 {
    11 
    12     private final static String QUEUE_NAME = "test_queue_work";
    13 
    14     public static void main(String[] args) throws IOException {
    15         Connection connection = ConnectionUtil.getConnection();
    16         Channel channel = connection.createChannel();
    17         channel.basicQos(1);//能者多劳模式
    18         //声明队列
    19         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    20         //自4.0+ 版本后无法再使用QueueingConsumer,而官方推荐使用DefaultConsumer
    21         Consumer consumer = new DefaultConsumer(channel) {
    22             @Override
    23             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    24                 throws IOException {
    25                 super.handleDelivery(consumerTag, envelope, properties, body);
    26                 String message = new String(body,"UTF-8");
    27                 System.out.println(message);
    28                 try {
    29                     Thread.sleep(1000);
    30                 } catch (InterruptedException e) {
    31                     e.printStackTrace();
    32                 }
    33                 try {
    34                     doWork(message);
    35                 }finally {
    36                     channel.basicAck(envelope.getDeliveryTag(), false);
    37                 }
    38             }
    39         };
    40         //监听队列,当b为true时,为自动提交(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息,都认为是消息已经成功消费),
    41         // 当b为false时,为手动提交(消费者从队列中获取消息后,服务器会将该消息标记为不可用状态,等待消费者的反馈,
    42         // 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。
    43         //如果选用自动确认,在消费者拿走消息执行过程中出现宕机时,消息可能就会丢失!!)
    44         //使用channel.basicAck(envelope.getDeliveryTag(),false);进行消息确认
    45         channel.basicConsume(QUEUE_NAME,false,consumer);
    46     }
    47 
    48     /** 
    49      * @Description: 业务代码
    50      * @Param:  
    51      * @return:  
    52      * @Author: 535504 
    53      * @Date: 2018/4/26 
    54      */ 
    55     private static void doWork(String task) {
    56         for (char ch : task.toCharArray()) {
    57             if (ch == '.') {
    58                 try {
    59                     Thread.sleep(1000);
    60                 } catch (InterruptedException _ignored) {
    61                     Thread.currentThread().interrupt();
    62                 }
    63             }
    64         }
    65     }
    66 
    67 }
    Consumer2.java

      测试结果,当消费者中的channel.basicQos(1);这行代码的注释打开时,执行会发现,休眠时间短的消费者执行的任务多,而注释后,再次执行会发现消费者1和消费者2获取到的消息内容是不同的,同一个消息只能被一个消费者获取,消费者1和消费者2获取到的消息的数量是相同的,一个是奇数一个是偶数。

      3、Publish/Subscribe(严格来说下面介绍的路由和通配符模式也是发布订阅)

      在发布订阅模式中,消息需要发送到MQ的交换机exchange上,exchange根据配置的路由方式发到相应的Queue上,Queue又将消息发送给consumer,消息从queue到consumer, 消息队列的使用过程大概如下:
      1.客户端连接到消息队列服务器,打开一个channel。
      2.客户端声明一个exchange,并设置相关属性。
      3.客户端声明一个queue,并设置相关属性。
      4.客户端在exchange和queue之间建立好绑定关系。
      5.客户端投递消息到exchange。

      

      创建生产者Producer: 

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.Channel;
     3 import com.rabbitmq.client.Connection;
     4 import java.io.IOException;
     5 import java.util.concurrent.TimeoutException;
     6 
     7 /**
     8  * @program: rabbit-learn
     9  * @description: 生产者,订阅模式
    10  * @author: 
    11  * @create: 
    12  * 消息发送到没有队列绑定的交换机时,消息将丢失,因为,交换机没有存储消息的能力,消息只能存在在队列中。
    13  **/
    14 public class Producer {
    15 
    16     //交换机名称
    17     private static final String EXCHANGE_NAME = "test_exchange_fanout";
    18 
    19     public static void main(String[] args) throws IOException, TimeoutException {
    20         Connection connection = ConnectionUtil.getConnection();
    21         Channel channel = connection.createChannel();
    22         /*
    23             声明exchange交换机
    24             参数1:交换机名称
    25             参数2:交换机类型
    26             参数3:交换机持久性,如果为true则服务器重启时不会丢失
    27             参数4:交换机在不被使用时是否删除
    28             参数5:交换机的其他属性
    29          */
    30         channel.exchangeDeclare(EXCHANGE_NAME,"fanout", true,true,null);
    31 
    32         String message = "订阅消息";
    33         channel.basicPublish(EXCHANGE_NAME,"",null,message.getBytes());
    34         System.out.println("生产者 send :"+message);
    35         channel.close();
    36         connection.close();
    37     }
    38 
    39 }
    Producer.java

      创建消费者Consumer1、2:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 import java.io.IOException;
     9 
    10 public class Consumer1 {
    11 
    12     private static final String QUEUE_NAME = "test_queue_exchange_1";
    13 
    14     private static final String EXCHANGE_NAME = "test_exchange_fanout";
    15 
    16     public static void main(String[] args) throws IOException {
    17         Connection connection = ConnectionUtil.getConnection();
    18         Channel channel = connection.createChannel();
    19 
    20         //声明队列
    21         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    22 
    23         /*
    24             绑定队列到交换机(这个交换机名称一定要和生产者的交换机名相同)
    25             参数1:队列名
    26             参数2:交换机名
    27             参数3:Routing key 路由键
    28          */
    29         channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"");
    30 
    31         //同一时刻服务器只会发一条数据给消费者
    32         channel.basicQos(1);
    33 
    34         Consumer consumer = new DefaultConsumer(channel) {
    35             @Override
    36             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    37                 throws IOException {
    38                 super.handleDelivery(consumerTag, envelope, properties, body);
    39                 String message = new String(body,"UTF-8");
    40                 System.out.println("收到消息:"+message);
    41                 channel.basicAck(envelope.getDeliveryTag(),false);
    42             }
    43         };
    44         channel.basicConsume(QUEUE_NAME,false,consumer);
    45     }
    46 
    47 }
    Consumer1.java
     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 import java.io.IOException;
     9 
    10 public class Consumer2 {
    11 
    12     private static final String QUEUE_NAME = "test_queue_exchange_2";
    13 
    14     private static final String EXCHANGE_NAME = "test_exchange_fanout";
    15 
    16     public static void main(String[] args) throws IOException {
    17         Connection connection = ConnectionUtil.getConnection();
    18         Channel channel = connection.createChannel();
    19 
    20         //声明队列
    21         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    22 
    23         /*
    24             绑定队列到交换机(这个交换机名称一定要和生产者的交换机名相同)
    25             参数1:队列名
    26             参数2:交换机名
    27             参数3:Routing key 路由键
    28          */
    29         channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"");
    30 
    31         //同一时刻服务器只会发一条数据给消费者
    32         channel.basicQos(1);
    33 
    34         Consumer consumer = new DefaultConsumer(channel) {
    35             @Override
    36             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    37                 throws IOException {
    38                 super.handleDelivery(consumerTag, envelope, properties, body);
    39                 String message = new String(body,"UTF-8");
    40                 System.out.println("收到消息:"+message);
    41                 channel.basicAck(envelope.getDeliveryTag(),false);
    42             }
    43         };
    44         channel.basicConsume(QUEUE_NAME,false,consumer);
    45     }
    46 
    47 }
    Consumer2.java

      4、Routing(路由)

      根据指定的路由键发送到对应的消息队列中,如下图,在这个设置中,我们可以看到与它绑定的两个队列的直接交换X。第一个队列绑定了绑定键橙色,第二个队列有两个绑定,一个绑定键为黑色,另一个为绿色。在这样的设置中,将发送到与路由键橙色的交换的消息将被路由到队列Q1。带有黑色或绿色的路由键的消息将会进入Q2。所有其他消息将被丢弃。

        

      创建生产者Producer:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.Channel;
     3 import com.rabbitmq.client.Connection;
     4 
     5 public class Producer {
     6 
     7     private static final String EXCHANGE_NAME = "test_exchange_direct";
     8 
     9     public static void main(String[] argv) throws Exception {
    10         // 获取到连接以及mq通道
    11         Connection connection = ConnectionUtil.getConnection();
    12         Channel channel = connection.createChannel();
    13 
    14         // 声明exchange,路由模式声明direct
    15         channel.exchangeDeclare(EXCHANGE_NAME, "direct");
    16 
    17         // 消息内容
    18         String message = "这是消息B";
    19         channel.basicPublish(EXCHANGE_NAME, "B", null, message.getBytes());
    20         String messageA = "这是消息A";
    21         channel.basicPublish(EXCHANGE_NAME, "A", null, messageA.getBytes());
    22         System.out.println(" [生产者] Sent '" + message + "'");
    23 
    24         channel.close();
    25         connection.close();
    26     }
    27 
    28 }
    Producer.java

      创建消费者Consumer1、2:

     1 package com.cn.routing;
     2 
     3 import com.cn.ConnectionUtil;
     4 import com.rabbitmq.client.AMQP.BasicProperties;
     5 import com.rabbitmq.client.Channel;
     6 import com.rabbitmq.client.Connection;
     7 import com.rabbitmq.client.Consumer;
     8 import com.rabbitmq.client.DefaultConsumer;
     9 import com.rabbitmq.client.Envelope;
    10 import java.io.IOException;
    11 
    12 /**
    13  * @program: rabbit-learn
    14  * @description: 消费者1
    15  * @author: 535504
    16  * @create: 2018-04-26 17:52
    17  **/
    18 public class Consumer1 {
    19     private final static String QUEUE_NAME = "test_queue_direct_A";
    20 
    21     private final static String EXCHANGE_NAME = "test_exchange_direct";
    22 
    23     public static void main(String[] argv) throws Exception {
    24 
    25         // 获取到连接以及mq通道
    26         Connection connection = ConnectionUtil.getConnection();
    27         Channel channel = connection.createChannel();
    28 
    29         // 声明队列
    30         //channel.queueDeclare(QUEUE_NAME, false, false, false, null);
    31         channel.exchangeDeclare(EXCHANGE_NAME,"direct");
    32         /*
    33          * 绑定队列到交换机
    34          * 参数1:队列的名称
    35          * 参数2:交换机的名称
    36          * 参数3:routingKey
    37          */
    38         channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "A");
    39 
    40         // 同一时刻服务器只会发一条消息给消费者
    41         channel.basicQos(1);
    42 
    43         // 定义队列的消费者
    44         Consumer consumer = new DefaultConsumer(channel) {
    45             @Override
    46             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    47                 throws IOException {
    48                 super.handleDelivery(consumerTag, envelope, properties, body);
    49                 System.out.println(new String(body,"UTF-8"));
    50             }
    51         };
    52         channel.basicConsume(QUEUE_NAME,true,consumer);
    53     }
    54 }
    Consumer1.java
     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 import java.io.IOException;
     9 
    10 public class Consumer2 {
    11     private final static String QUEUE_NAME = "test_queue_direct_B";
    12 
    13     private final static String EXCHANGE_NAME = "test_exchange_direct";
    14 
    15     public static void main(String[] argv) throws Exception {
    16 
    17         // 获取到连接以及mq通道
    18         Connection connection = ConnectionUtil.getConnection();
    19         Channel channel = connection.createChannel();
    20 
    21         // 声明队列
    22         //channel.queueDeclare(QUEUE_NAME, false, false, false, null);
    23         channel.exchangeDeclare(EXCHANGE_NAME,"direct");
    24         /*
    25          * 绑定队列到交换机
    26          * 参数1:队列的名称
    27          * 参数2:交换机的名称
    28          * 参数3:routingKey
    29          */
    30         channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "B");
    31 
    32         // 同一时刻服务器只会发一条消息给消费者
    33         channel.basicQos(1);
    34 
    35         // 定义队列的消费者
    36         Consumer consumer = new DefaultConsumer(channel) {
    37             @Override
    38             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    39                 throws IOException {
    40                 super.handleDelivery(consumerTag, envelope, properties, body);
    41                 System.out.println(new String(body,"UTF-8"));
    42             }
    43         };
    44         channel.basicConsume(QUEUE_NAME,true,consumer);
    45     }
    46 }
    Consumer2.java

      5、Topics(主题通配符)

      可以理解为Routing的通配符模式,如下图:

      

      “#”:表示匹配一个或多个词;(lazy.a.b.c)

      “*”:表示匹配一个词;(a.orange.b)

      创建生产者Producer:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.Channel;
     3 import com.rabbitmq.client.Connection;
     4 
     5 import java.io.IOException;
     6 import java.util.concurrent.TimeoutException;
     7 
     8 public class Producer {
     9 
    10     private static final String EXCHANGE_NAME = "test_exchange_topic";
    11 
    12     public static void main(String[] args) throws IOException, TimeoutException {
    13         Connection connection = ConnectionUtil.getConnection();
    14         Channel channel = connection.createChannel();
    15         //声明交换机
    16         channel.exchangeDeclare(EXCHANGE_NAME,"topic");
    17         String message = "匹配insert";
    18         channel.basicPublish(EXCHANGE_NAME,"order.update",false,false,null,message.getBytes());
    19 
    20         channel.close();
    21         connection.close();
    22     }
    23 }
    Producer.java

      创建消费者Consumer1、2:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 
     9 import java.io.IOException;
    10 
    11 public class Consumer1 {
    12 
    13     private static final String EXCHANGE_NAME = "test_exchange_topic";
    14 
    15     private  static final String QUEUE_NAME = "test_queue_topic_1";
    16 
    17     public static void main(String[] args) throws IOException {
    18         Connection connection = ConnectionUtil.getConnection();
    19         Channel channel = connection.createChannel();
    20         //channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    21         channel.exchangeDeclare(EXCHANGE_NAME,"topic");
    22         //order.#
    23         channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"order.*");
    24 
    25         channel.basicQos(1);
    26 
    27         Consumer consumer = new DefaultConsumer(channel) {
    28             @Override
    29             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
    30                 throws IOException {
    31                 super.handleDelivery(consumerTag, envelope, properties, body);
    32                 System.out.println(new String(body,"UTF-8"));
    33             }
    34         };
    35         channel.basicConsume(QUEUE_NAME,true,consumer);
    36 
    37     }
    38 }
    Consumer1.java
     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP.BasicProperties;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 
     9 import java.io.IOException;
    10 
    11 public class Consumer2 {
    12 
    13     private static final String EXCHANGE_NAME = "test_exchange_topic";
    14 
    15     private  static final String QUEUE_NAME = "test_queue_topic_2";
    16 
    17     public static void main(String[] args) throws IOException {
    18         Connection connection = ConnectionUtil.getConnection();
    19         Channel channel = connection.createChannel();
    20         channel.queueDeclare(QUEUE_NAME,false,false,false,null);
    21 
    22         channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,"order.insert");
    23 
    24         channel.basicQos(1);
    25 
    26         Consumer consumer = new DefaultConsumer(channel) {
    27             @Override
    28             public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body) throws IOException {
    29                 super.handleDelivery(consumerTag, envelope, properties, body);
    30                 System.out.println("接收消息:" + new String(body, "UTF-8"));
    31             }
    32         };
    33         channel.basicConsume(QUEUE_NAME,true,consumer);
    34 
    35     }
    36 }
    Consumer2.java

      6、RPC(远程调用)

      如果我们需要在远程计算机上运行一个函数并等待结果,这种模式通常称为远程过程调用或RPC;

       

      创建RPC服务:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.Consumer;
     6 import com.rabbitmq.client.DefaultConsumer;
     7 import com.rabbitmq.client.Envelope;
     8 
     9 import java.io.IOException;
    10 import java.util.concurrent.TimeoutException;
    11 
    12 public class RPCServer {
    13 
    14     private static final String RPC_QUEUE_NAME = "rpc_queue";
    15 
    16     public static void main(String[] args) throws IOException, TimeoutException {
    17         Connection connection = ConnectionUtil.getConnection();
    18         final Channel channel = connection.createChannel();
    19         channel.queueDeclare(RPC_QUEUE_NAME, false, false, false, null);
    20         channel.basicQos(1);
    21 
    22         Consumer consumer = new DefaultConsumer(channel) {
    23             @Override
    24             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
    25                 super.handleDelivery(consumerTag, envelope, properties, body);
    26                 AMQP.BasicProperties properties1 = new AMQP.BasicProperties.Builder().correlationId(properties.getCorrelationId()).build();
    27                 String mes = new String(body, "UTF-8");
    28                 int num = Integer.valueOf(mes);
    29                 System.out.println("接收数据:" + num);
    30                 num = fib(num);
    31                 channel.basicPublish("", properties.getReplyTo(), properties1, String.valueOf(num).getBytes());
    32                 channel.basicAck(envelope.getDeliveryTag(), false);
    33             }
    34         };
    35         channel.basicConsume(RPC_QUEUE_NAME, false, consumer);
    36         while (true) {
    37             synchronized (consumer) {
    38                 try {
    39                     consumer.wait();
    40                 } catch (InterruptedException e) {
    41                     e.printStackTrace();
    42                 }
    43             }
    44         }
    45     }
    46 
    47     /*
    48         获取斐波那契数列的第n个值得大小
    49      */
    50     private static int fib(int n) {
    51         System.out.println(n);
    52         if (n == 0)
    53             return 0;
    54         if (n == 1)
    55             return 1;
    56         return fib(n - 1) + fib(n - 2);
    57     }
    58 }
    RPCServer.java

      创建RPC客户端:

     1 import com.cn.ConnectionUtil;
     2 import com.rabbitmq.client.AMQP;
     3 import com.rabbitmq.client.Channel;
     4 import com.rabbitmq.client.Connection;
     5 import com.rabbitmq.client.DefaultConsumer;
     6 import com.rabbitmq.client.Envelope;
     7 
     8 import java.io.IOException;
     9 import java.util.UUID;
    10 import java.util.concurrent.ArrayBlockingQueue;
    11 import java.util.concurrent.BlockingQueue;
    12 import java.util.concurrent.TimeoutException;
    13 
    14 public class RPCClient {
    15 
    16     private Connection connection;
    17     private Channel channel;
    18     private String requestQueueName = "rpc_queue";
    19     private String replyQueueName;
    20 
    21     public RPCClient() throws IOException, TimeoutException {
    22         connection = ConnectionUtil.getConnection();
    23         channel = connection.createChannel();
    24 
    25         replyQueueName = channel.queueDeclare().getQueue();
    26     }
    27 
    28     public String call(String message) throws IOException, InterruptedException {
    29         final String corrId = UUID.randomUUID().toString();
    30 
    31         AMQP.BasicProperties props = new AMQP.BasicProperties
    32                 .Builder()
    33                 .correlationId(corrId)
    34                 .replyTo(replyQueueName)
    35                 .build();
    36 
    37         channel.basicPublish("", requestQueueName, props, message.getBytes("UTF-8"));
    38 
    39         final BlockingQueue<String> response = new ArrayBlockingQueue<String>(1);
    40 
    41         channel.basicConsume(replyQueueName, true, new DefaultConsumer(channel) {
    42             @Override
    43             public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
    44                 if (properties.getCorrelationId().equals(corrId)) {
    45                     response.offer(new String(body, "UTF-8"));
    46                 }
    47             }
    48         });
    49 
    50         //close();
    51         return response.take();
    52     }
    53 
    54     public void close() throws IOException {
    55         connection.close();
    56     }
    57 
    58 }
    RPCClient.java

      创建RPC测试类:

     1 import java.io.IOException;
     2 import java.util.concurrent.TimeoutException;
     3 
     4 public class RPCTest {
     5 
     6     public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
     7         RPCClient rpcClient = new RPCClient();
     8         System.out.println(rpcClient.call("2"));
     9     }
    10 }
    RPCTest

    完整示例https://gitee.com/lfalex/rabbitmq-learn

    参考官方文档:http://www.rabbitmq.com/getstarted.html

    版权声明:本文为博主原创文章,转载请注明出处,谢谢!
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  • 原文地址:https://www.cnblogs.com/lfalex0831/p/8963247.html
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