RabbitMQ java helloworld 问题记录

Demo 参考 https://blog.****.net/u011126891/article/details/54288263 有详细讲解

 

Send.java

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

/**
 * Create By Cuixk
 * 2018/10/17 09:36
 */
public class Send {

    private final static String QUEUE_NAME = "hello";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setUsername("guest");
        factory.setPassword("guest");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        channel.queueDeclare("hello", false, false, false, null);
        String message = "hello world!!!! 你好啊~";
        channel.basicPublish("",QUEUE_NAME,null,message.getBytes());
        System.out.println(" [x] Sent " + message +"'");
        channel.close();
        connection.close();
    }
}

Recv.java

import com.rabbitmq.client.*;

import java.io.IOException;

public class Recv {

    private final static String QUEUE_NAME = "hello";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setUsername("guest");
        factory.setPassword("guest");
        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");

        Consumer consumer = new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body)
                    throws IOException {
                String message = new String(body, "UTF-8");
                System.out.println(" [x] Received '" + message + "'");
            }
        };
        channel.basicConsume(QUEUE_NAME, true, consumer);
    }
}

一，启动recv.java时报错

Exception in thread "main" java.io.IOException
	at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:126)
	at com.rabbitmq.client.impl.AMQChannel.wrap(AMQChannel.java:122)
	at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:144)
	at com.rabbitmq.client.impl.ChannelN.queueDeclare(ChannelN.java:962)
	at com.rabbitmq.client.impl.recovery.AutorecoveringChannel.queueDeclare(AutorecoveringChannel.java:333)
	at Send.main(Send.java:24)
Caused by: com.rabbitmq.client.ShutdownSignalException: channel error; protocol method: #method<channel.close>(reply-code=406, reply-text=PRECONDITION_FAILED - inequivalent arg 'durable' for queue 'hello' in vhost '/': received 'false' but current is 'true', class-id=50, method-id=10)
	at com.rabbitmq.utility.ValueOrException.getValue(ValueOrException.java:66)
	at com.rabbitmq.utility.BlockingValueOrException.uninterruptibleGetValue(BlockingValueOrException.java:36)
	at com.rabbitmq.client.impl.AMQChannel$BlockingRpcContinuation.getReply(AMQChannel.java:494)
	at com.rabbitmq.client.impl.AMQChannel.privateRpc(AMQChannel.java:288)
	at com.rabbitmq.client.impl.AMQChannel.exnWrappingRpc(AMQChannel.java:138)
	... 3 more

原因是：

我的队列hello 在可视化页面创建时Durability 属性为 Durable 即消息队列是持久化，

对应Java中这一句的设置

Queue.DeclareOk queueDeclare(String queue, boolean durable, boolean exclusive, boolean autoDelete,Map<String, Object> arguments) throws IOException;

而我的代码是，第二个为false，即消息队列非持久化，与设置的不符

channel.queueDeclare(QUEUE_NAME, false, false, false, null);

应该改为

channel.queueDeclare(QUEUE_NAME, true, false, false, null);

二、消息发送Send启动3次，却只有一条message能被Recv收到

原因可能是：我多次启动Recv，打开了多个通道，却没有及时关闭。因此队列可能由于某种转发规则，轮询或者什么其他原因，这个有待考证，只有一条能被Recv收到

我的解决办法：关闭所有java进程，关闭IDE，重新打开IDE，重启解决问题