rabbitMQ实战应用

rabbitMQ实战应用

1. 异步任务处理：在Java项目中，可以将一些耗时的任务（如文件处理、邮件发送等）放入消息队列中，由后台的消费者异步地处理这些任务，提高系统的吞吐量和响应速度。

   // 生产者
   public class TaskProducer {
       private final static String QUEUE_NAME = "task_queue";
   
       public static void main(String[] argv) throws Exception {
           ConnectionFactory factory = new ConnectionFactory();
           factory.setHost("localhost");
           try (Connection connection = factory.newConnection(); 
                Channel channel = connection.createChannel()) {
               channel.queueDeclare(QUEUE_NAME, true, false, false, null);
               String message = "hello";
               channel.basicPublish("", QUEUE_NAME, MessageProperties.PERSISTENT_TEXT_PLAIN, message.getBytes("UTF-8"));
               System.out.println(" [x] Sent '" + message + "'");
           }
       }
   }
   
   // 消费者
   public class TaskConsumer {
       private final static String QUEUE_NAME = "task_queue";
   
       public static void main(String[] argv) throws Exception {
           ConnectionFactory factory = new ConnectionFactory();
           factory.setHost("localhost");
           try (Connection connection = factory.newConnection(); 
                Channel channel = connection.createChannel()) {
               channel.queueDeclare(QUEUE_NAME, true, false, false, null);
               System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
               DeliverCallback deliverCallback = (consumerTag, delivery) -> {
                   String message = new String(delivery.getBody(), "UTF-8");
                   System.out.println(" [x] Received '" + message + "'");
                   try {
                       doWork(message);
                   } finally {
                       System.out.println(" [x] Done");
                       channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
                   }
               };
               channel.basicConsume(QUEUE_NAME, false, deliverCallback, consumerTag -> { });
           }
       }
   
       private static void doWork(String task) {
           try {
               Thread.sleep(1000); // 模拟耗时任务
           } catch (InterruptedException _ignored) {
               Thread.currentThread().interrupt();
           }
       }
   }
   

2. 事件驱动架构：通过RabbitMQ实现事件驱动架构，不同模块之间通过消息进行通信，从而实现松耦合、高内聚的系统架构。

   // 生产者
   public class EventProducer {
       private final static String EXCHANGE_NAME = "events";
   
       public static void main(String[] argv) throws Exception {
           ConnectionFactory factory = new ConnectionFactory();
           factory.setHost("localhost");
           try (Connection connection = factory.newConnection(); 
                Channel channel = connection.createChannel()) {
               channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);
               String message = "event message";
               channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes("UTF-8"));
               System.out.println(" [x] Sent '" + message + "'");
           }
       }
   }
   
   // 消费者
   public class EventConsumer {
       private final static String EXCHANGE_NAME = "events";
   
       public static void main(String[] argv) throws Exception {
           ConnectionFactory factory = new ConnectionFactory();
           factory.setHost("localhost");
           try (Connection connection = factory.newConnection(); 
                Channel channel = connection.createChannel()) {
               channel.exchangeDeclare(EXCHANGE_NAME, BuiltinExchangeType.FANOUT);
               String queueName = channel.queueDeclare().getQueue();
               channel.queueBind(queueName, EXCHANGE_NAME, "");
               System.out.println(" [*] Waiting for events. To exit press CTRL+C");
               DeliverCallback deliverCallback = (consumerTag, delivery) -> {
                   String message = new String(delivery.getBody(), "UTF-8");
                   System.out.println(" [x] Received '" + message + &