在实际工作中有时候需要的是根据实际情况来分发消息，也就是路由模式。生产者在发送消息时为消息指定路由键，队列在与交换机绑定时也约定路由键，这样当消息发送到交换机的时候，交换机就会根据约定的路由键来向特定的队列发送消息。具体的我们来看示例代码，其中也有详细的注释。
生产者
package com.mmr.rabbitmq.direct;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
import com.mmr.rabbitmq.util.ConnectionUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
public class Send {
private static final String EXCHANGE_NAME = "exchange_topic";
public static void main(String[] args) throws IOException, TimeoutException {
Connection connection = ConnectionUtils.getConnection();
Channel channel = connection.createChannel();
//声明交换机，并将交换机的类型设置为direct
channel.exchangeDeclare(EXCHANGE_NAME, "direct");
String message = "this is topic message--->";
for (int i = 0; i < 50; i++) {
//发送消息，并注明该消息的路由键，即第二个参数
channel.basicPublish(EXCHANGE_NAME, "delete", null, (message + i).getBytes());
// channel.basicPublish(EXCHANGE_NAME, "insert", null, (message + i).getBytes());
System.out.println(message + i);
}
channel.close();
connection.close();
}
}
消费者1
接收约定路由键为insert和delete的消息
package com.mmr.rabbitmq.direct;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
import com.mmr.rabbitmq.util.ConnectionUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.rabbitmq.client.AMQP.BasicProperties;
public class RecvAll {
private static final String EXCHANGE_NAME = "exchange_topic";
private static final String QUEUE_NAME = "queue_topic_delete";
public static void main(String[] args) throws IOException, TimeoutException {
Connection connection = ConnectionUtils.getConnection();
final Channel channel = connection.createChannel();
channel.queueDeclare(QUEUE_NAME, false, false, false, null);
channel.basicQos(1);
//绑定队列与交换机，并指定绑定的路由键为insert和delete
//同一个队列绑定交换机时可以指定多个路由键
channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "delete");
channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "insert");
DefaultConsumer consumer = new DefaultConsumer(channel){
@Override
public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
throws IOException {
try {
String msg = new String(body, "utf-8");
Thread.sleep(2000);
System.out.println(msg);
} catch (Exception e) {
e.printStackTrace();
}finally {
//向MQ发送确认，告诉MQ该条消息已经消费，可以重新发送了
//第二个参数为false表示只确认当前这一条消息，
//如果为 true，则额外将比第一个参数指定的 delivery tag 小的消息一并确认（批量确认针对的是整个信道）
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
};
channel.basicConsume(QUEUE_NAME, false, consumer);
}
}
消费者2
只接收约定路由键为insert的消息
package com.mmr.rabbitmq.direct;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
import com.mmr.rabbitmq.util.ConnectionUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.rabbitmq.client.AMQP.BasicProperties;
public class RecvInsert {
private static final String EXCHANGE_NAME = "exchange_topic";
private static final String QUEUE_NAME = "queue_topic_insert";
public static void main(String[] args) throws IOException, TimeoutException {
Connection connection = ConnectionUtils.getConnection();
final Channel channel = connection.createChannel();
channel.queueDeclare(QUEUE_NAME, false, false, false, null);
channel.basicQos(1);
channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "insert");
DefaultConsumer consumer = new DefaultConsumer(channel){
@Override
public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body)
throws IOException {
try {
String msg = new String(body, "utf-8");
Thread.sleep(2000);
System.out.println(msg);
} catch (Exception e) {
e.printStackTrace();
}finally {
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
};
channel.basicConsume(QUEUE_NAME, false, consumer);
}
}
运行两个消费者，然后让生产者以不同的路由键来发送消息，从控制台的打印信息便能更加直观的看出来该模式的应用情况。