新来个技术总监，把 RabbitMQ 讲得那叫一个透彻，佩服( 六 ) _RabbitMQ

public void publishMsg(String routingKey, String msg) {
try {
MsgProducer.publishMsg(EXCHANGE_NAME, BuiltinExchangeType.DIRECT, routingKey, msg);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws InterruptedException {
DirectProducer directProducer = new DirectProducer();
String[] routingKey = new String[]{"aaa", "bbb", "ccc"};
String msg = "hello >>> ";
for (int i = 0; i < 10; i++) {
directProducer.publishMsg(routingKey[i % 3], msg + i);
}
System.out.println("----over-------");
Thread.sleep(1000 * 60 * 100);
}
}
执行生产者，往消息队列中放入10条消息，其中key分别为“aaa”、“bbb”和“ccc”，分别放入qa、qb、qc三个队列：

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下面是qa队列的信息：

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消费者：
public class DirectConsumer {
private static final String exchangeName = "direct.exchange";
public void msgConsumer(String queueName, String routingKey) {
try {
MsgConsumer.consumerMsg(exchangeName, queueName, routingKey);
} catch (IOException e) {
e.printStackTrace();
} catch (TimeoutException e) {
e.printStackTrace();
}
}
public static void main(String[] args) throws InterruptedException {
DirectConsumer consumer = new DirectConsumer();
String[] routingKey = new String[]{"aaa", "bbb", "ccc"};
String[] queueNames = new String[]{"qa", "qb", "qc"};
for (int i = 0; i < 3; i++) {
consumer.msgConsumer(queueNames[i], routingKey[i]);
}
Thread.sleep(1000 * 60 * 100);
}
}
执行后的输出：
[*] Waiting for message. To exist press CTRL+C
[x] Received 'hello >>> 0
[x] Done
[x] Received 'hello >>> 3
[x] Done
[x] Received 'hello >>> 6
[x] Done
[x] Received 'hello >>> 9
[x] Done
[*] Waiting for message. To exist press CTRL+C
[x] Received 'hello >>> 1
[x] Done
[x] Received 'hello >>> 4
[x] Done
[x] Received 'hello >>> 7
[x] Done
[*] Waiting for message. To exist press CTRL+C
[x] Received 'hello >>> 2
[x] Done
[x] Received 'hello >>> 5
[x] Done
[x] Received 'hello >>> 8
[x] Done
可以看到，分别从qa、qb、qc中将不同的key的数据消费掉。
5.2.2 问题探讨

有个疑问：这个队列的名称qa、qb和qc是RabbitMQ自动生成的么，我们可以指定队列名称么？

我做了个简单的实验，我把消费者代码修改了一下：
public static void main(String[] args) throws InterruptedException {
DirectConsumer consumer = new DirectConsumer();
String[] routingKey = new String[]{"aaa", "bbb", "ccc"};
String[] queueNames = new String[]{"qa", "qb", "qc1"}; // 将qc修改为qc1
for (int i = 0; i < 3; i++) {
consumer.msgConsumer(queueNames[i], routingKey[i]);
}
Thread.sleep(1000 * 60 * 100);
}
执行后如下图所示：

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我们可以发现，多了一个qc1，所以可以判断这个界面中的queues，是消费者执行时，会将消费者指定的队列名称和direct.exchange绑定，绑定的依据就是key 。
当我们把队列中的数据全部消费掉，然后重新执行生成者后，会发现qc和qc1中都有3条待消费的数据，因为绑定的key都是“ccc”，所以两者的数据是一样的：