Routing(路由模式)

• Routing(路由模式)

  生产者将消息发送到direct交换器,在绑定队列和交换器的时候有一个路由key,生产者发送的消息会指定一个路由key,那么消息只会发送到相应key相同的队列,接着监听该队列的消费者消费信息.

  • Direct exchange

    会把消息路由到那些binding key与routing key完全匹配的Queue中
    我们可以看到绑定了两个队列的exchange X。第一个队列binding key 为orange，第二个binding key为两个，一个binding key为black，另一个binding key为green。
    使用routing key为orange发布到交换机的消息 将被路由到队列Q1。routing key为black 或green的消息将转到Q2。所有其他消息将被丢弃。

    Multiple Bindings

    用相同的binding key 绑定多个队列，可以使用binding key 为black在X和Q1与Q2之间添加绑定。在这种情况下，exchange的行为将类似于扇出，并将消息广播到所有匹配的队列。routing key为black的消息将同时传递给 Q1和Q2

    

  • 下面代码实现生产者和消费者的Direct模式

    生产者代码：

    public class DirectEmitLog {
    
        private static final String EXCHANGE_NAME = "direct_logs";
        
        public static void main(String[] args) throws Exception {
            //获取连接
            Connection connection = ConnectionUtil.getConnection("localhost", 5672, "/", "guest", "guest");
        
            Channel channel = connection.createChannel();
        
            //创建队列
            channel.queueDeclare("direct_loge",false,false,false,null);
            //声明交换机，
            channel.exchangeDeclare(EXCHANGE_NAME, "direct");
        
            String message="hello";
            //发送消息
    
    //        for (int i = 0; i < 10; i++) {
    //            String message = " message" + i;
    //            System.out.println("[send]：" + message);
                //发送消息
                channel.basicPublish(EXCHANGE_NAME, "err", null, message.getBytes("utf-8"));
    
            //}
            channel.close();
            connection.close();
        
        }
    
    }
    

    消费者代码：

    public class DirectRecv {
    
        private final static String QUEUE_NAME = "direct_loge";
        private static final String EXCHANGE_NAME = "direct_logs";
        public static void main(String[] args) throws Exception {
            //获取连接
            Connection connection = ConnectionUtil.getConnection("localhost", 5672, "/", "guest", "guest");
        
            //声明通道
            Channel channel = connection.createChannel();
        
            channel.exchangeDeclare(EXCHANGE_NAME, "direct");
        
            //声明队列队列
            channel.queueDeclare(QUEUE_NAME, false, false, false, null);
            channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "err");
        
            DeliverCallback deliverCallback = (consumerTag, delivery) -> {
                String message = new String(delivery.getBody(), "UTF-8");
        
                System.out.println(" [x] Received '" + message + "'");
                try {
                    doWork(message);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                } finally {
                    System.out.println(" [x] Done");
                    //channel.basicAck();
                    //channel.basicNack();
                }
            };
            boolean autoAck = true; // acknowledgment is covered below
            channel.basicConsume(QUEUE_NAME, autoAck, deliverCallback, consumerTag -> {
            });
    
    
    //        DeliverCallback deliverCallback = new DeliverCallback(){
    //            @Override
    //            public void handle(String consumerTag, Delivery delivery) throws IOException {
    //                String message = new String(delivery.getBody(), "UTF-8");
    //                System.out.println(" [x] Received '" + message + "'");
    //            }
    //        };
    //
    //        channel.basicConsume(QUEUE_NAME, true, deliverCallback, new CancelCallback(){
    //            @Override
    //            public void handle(String consumerTag) throws IOException {
    //
    //            }
    //        });
    
        }
        
        private static void doWork(String task) throws InterruptedException {
            for (char ch : task.toCharArray()) {
                if (ch == '.') Thread.sleep(1000);
            }
        }
    
    }
    

  • SpringBoot相关代码：

    @SpringBootApplication
    @EnableScheduling
    public class RabbitAmqpTutorialsApplication {
    
        public static void main(String[] args) throws Exception {
            SpringApplication.run(RabbitAmqpTutorialsApplication.class, args);
        }
    
    }
    

    @Configuration
    public class Tut4Config {
    
        @Bean
        public DirectExchange direct() {
            return new DirectExchange("tut.direct");
        }
        
        private static class ReceiverConfig {
        
            @Bean
            public Queue autoDeleteQueue1() {
                return new AnonymousQueue();
            }
        
            @Bean
            public Queue autoDeleteQueue2() {
                return new AnonymousQueue();
            }
        
            @Bean
            public Binding binding1a(DirectExchange direct,
                                     Queue autoDeleteQueue1) {
                return BindingBuilder.bind(autoDeleteQueue1)
                        .to(direct)
                        .with("orange");
            }
        
            @Bean
            public Binding binding1b(DirectExchange direct,
                                     Queue autoDeleteQueue1) {
                return BindingBuilder.bind(autoDeleteQueue1)
                        .to(direct)
                        .with("black");
            }
        
            @Bean
            public Binding binding2a(DirectExchange direct,
                                     Queue autoDeleteQueue2) {
                return BindingBuilder.bind(autoDeleteQueue2)
                        .to(direct)
                        .with("green");
            }
        
            @Bean
            public Binding binding2b(DirectExchange direct,
                                     Queue autoDeleteQueue2) {
                return BindingBuilder.bind(autoDeleteQueue2)
                        .to(direct)
                        .with("black");
            }
        
            @Bean
            public Tut4Receiver receiver() {
                return new Tut4Receiver();
            }
        }
        
        @Bean
        public Tut4Sender sender() {
            return new Tut4Sender();
        }
    
    }
    

    public class Tut4Receiver {
    
        @RabbitListener(queues = "#{autoDeleteQueue1.name}")
        public void receive1(String in) throws InterruptedException {
            receive(in, 1);
        }
        
        @RabbitListener(queues = "#{autoDeleteQueue2.name}")
        public void receive2(String in) throws InterruptedException {
            receive(in, 2);
        }
        
        public void receive(String in, int receiver) throws InterruptedException {
            StopWatch watch = new StopWatch();
            watch.start();
            System.out.println("instance " + receiver + " [x] Received '" + in + "'");
            doWork(in);
            watch.stop();
            System.out.println("instance " + receiver + " [x] Done in " +
                    watch.getTotalTimeSeconds() + "s");
        }
        
        private void doWork(String in) throws InterruptedException {
            for (char ch : in.toCharArray()) {
                if (ch == '.') {
                    Thread.sleep(1000);
                }
            }
        }
    
    }
    

    public class Tut4Sender {
    
        @Autowired
        private RabbitTemplate template;
        
        @Autowired
        private DirectExchange direct;
        
        AtomicInteger index = new AtomicInteger(0);
        
        AtomicInteger count = new AtomicInteger(0);
        
        private final String[] keys = {"orange", "black", "green"};
        
        @Scheduled(fixedDelay = 1000, initialDelay = 500)
        public void send() {
            StringBuilder builder = new StringBuilder("Hello to ");
            if (this.index.incrementAndGet() == 3) {
                this.index.set(0);
            }
            String key = keys[this.index.get()];
            builder.append(key).append(' ');
            builder.append(this.count.get());
            String message = builder.toString();
            template.convertAndSend(direct.getName(), key, message);
            System.out.println(" [x] Sent '" + message + "'");
        }
    
    }
    

    相关代码链接： https://github.com/albert-liu435/springmq