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RabbitMQ Tutorials — RabbitMQhttps://rabbitmq.com/getstarted.html

1. 订阅模式

订阅：微信中的公众号，所有订阅该公众号的人都会接受到该消息。

注意：

1. 消息是发送到交换机而不是队列
2. 消息可以发送到队列，也可以发送到交换机
3. 消费者的消息来源只能是队列

如果将消息发送到没有绑定队列的交换机上，消息会去哪？

1. 消息存放在交换机
2. 消息丢失

说明：消息只能存放于队列，不能存放到交换机，交换机只是用于消息的传递。

2. 队列绑定到交换机

3. 生产者 

public class Send {private final static String EXCHANGE_NAME = "test_exchange_fanout";public static void main(String[] argv) throws Exception {// 获取到连接以及mq通道Connection connection = ConnectionUtil.getConnection();Channel channel = connection.createChannel();// 声明exchangechannel.exchangeDeclare(EXCHANGE_NAME, "fanout");// 消息内容String message = "Hello World!";channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes());System.out.println(" [x] Sent '" + message + "'");// 关闭连接channel.close();connection.close();}
}

4. ​​​​​​​消费者1​​​​​​​

public class Recv {private final static String QUEUE_NAME = "test_queue_work";private final static String EXCHANGE_NAME = "test_exchange_fanout";public static void main(String[] argv) throws Exception {// 获取到连接以及mq通道Connection connection = ConnectionUtil.getConnection();Channel channel = connection.createChannel();// 声明队列channel.queueDeclare(QUEUE_NAME, false, false, false, null);// 绑定队列到交换机channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "");// 同一时刻服务器只会发一条消息给消费者channel.basicQos(1);// 定义队列的消费者QueueingConsumer consumer = new QueueingConsumer(channel);// 监听队列，手动返回完成channel.basicConsume(QUEUE_NAME, false, consumer);// 获取消息while (true) {QueueingConsumer.Delivery delivery = consumer.nextDelivery();String message = new String(delivery.getBody());System.out.println(" [x] Received '" + message + "'");Thread.sleep(10);// 返回确认状态channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);}}
}

​​​​​​​5. 消费者2

public class Recv2 {private final static String QUEUE_NAME = "test_queue_work2";private final static String EXCHANGE_NAME = "test_exchange_fanout";public static void main(String[] argv) throws Exception {// 获取到连接以及mq通道Connection connection = ConnectionUtil.getConnection();Channel channel = connection.createChannel();// 声明队列channel.queueDeclare(QUEUE_NAME, false, false, false, null);// 绑定队列到交换机channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "");// 同一时刻服务器只会发一条消息给消费者channel.basicQos(1);// 定义队列的消费者QueueingConsumer consumer = new QueueingConsumer(channel);// 监听队列，手动返回完成channel.basicConsume(QUEUE_NAME, false, consumer);// 获取消息while (true) {QueueingConsumer.Delivery delivery = consumer.nextDelivery();String message = new String(delivery.getBody());System.out.println(" [x] Received '" + message + "'");Thread.sleep(10);// 返回确认状态channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);}}
}

5. 消费者3

public class Recv3 {private final static String QUEUE_NAME = "test_queue_work";private final static String EXCHANGE_NAME = "test_exchange_fanout";public static void main(String[] argv) throws Exception {// 获取到连接以及mq通道Connection connection = ConnectionUtil.getConnection();Channel channel = connection.createChannel();// 声明队列channel.queueDeclare(QUEUE_NAME, false, false, false, null);// 绑定队列到交换机channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "");// 同一时刻服务器只会发一条消息给消费者channel.basicQos(1);// 定义队列的消费者QueueingConsumer consumer = new QueueingConsumer(channel);// 监听队列，手动返回完成channel.basicConsume(QUEUE_NAME, false, consumer);// 获取消息while (true) {QueueingConsumer.Delivery delivery = consumer.nextDelivery();String message = new String(delivery.getBody());System.out.println(" [x] Received '" + message + "'");Thread.sleep(10);// 返回确认状态channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);}}
}

6. 测试

结果：消费者1和消费者2同时都能获取到消息。

注意：订阅模式和work模式的区别。

1. work模式将消息发送到队列

2. 订阅模式将消息发送到交换机

3. work模式是1个队列2个消费者，订阅模式是2个队列2个消费者