7.RabbitMQ RFC同步调用

RabbitMQ RFC同步调用是使用了两个异步调用完成的，生产者调用消费者的同时，自己也作为消费者等待某一队列的返回消息，消费者接受到生产者的消息同时，也作为消息发送者发送一消息给生产者。参考下图：

调用流程如下：

其他的消息服务器实现同步调用也是类似的原理，比如ActiveMQ。

 

下面编写消费者类Server

生产者Client代码

启动一命令行，将当前目录转移到项目所在的目录

在Eclipse中运行Client

 

 

代码：

package com.test.rfc;

 

import java.io.IOException;

 

import com.rabbitmq.client.AMQP;

import com.rabbitmq.client.Channel;

import com.rabbitmq.client.Connection;

import com.rabbitmq.client.ConnectionFactory;

import com.rabbitmq.client.Consumer;

import com.rabbitmq.client.DefaultConsumer;

import com.rabbitmq.client.Envelope;

 

public class Server {

public static void main(String[] argv) {

ConnectionFactory factory = new ConnectionFactory();

   
factory.setUsername("admin");

   
factory.setPassword("admin");

     
  factory.setHost("192.168.169.142");
//使用默认端口5672

     
  Connection connection = null;

     
  

try {

connection = factory.newConnection();

final Channel channel = connection.createChannel();

String queueName = "queue_rpc";

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

Consumer consumer = new DefaultConsumer(channel) {

 

@Override

public void handleDelivery(String consumerTag,

Envelope envelope, AMQP.BasicProperties properties,

byte[] body) throws IOException 

{

System.out.println("test1" + new String(body));

AMQP.BasicProperties replyProps = new
AMQP.BasicProperties.Builder()

.correlationId(properties.getCorrelationId())

.build();

String response = "hello client,I'm rfc server";

channel.basicPublish("", properties.getReplyTo(),

replyProps, response.getBytes());

channel.basicAck(envelope.getDeliveryTag(), false);

}

};

channel.basicConsume(queueName, false, consumer);

} catch (IOException e) {

e.printStackTrace();

}

}

 

}

 

package com.test.rfc;

 

import java.io.IOException;

import java.util.UUID;

import java.util.concurrent.ArrayBlockingQueue;

import java.util.concurrent.BlockingQueue;

 

import com.rabbitmq.client.*;

 

public class Client {

public static void main(String[] argv) {

try

{

//发送消息的队列,Server在这个队列上接受消息

String queueName = "queue_rpc";

ConnectionFactory factory = new ConnectionFactory();

   
factory.setUsername("admin");

   
factory.setPassword("admin");

     
 factory.setHost("192.168.169.142");
//使用默认端口5672

     
 Connection connection = null;

connection = factory.newConnection();

Channel channel = connection.createChannel();

//生成临时的队列,Client在这队列上等待Server返回信息,Server向这个队列发消息

String replyQueueName =
channel.queueDeclare().getQueue();

//生成唯一ID

final String corrId = UUID.randomUUID().toString();

AMQP.BasicProperties props = new
AMQP.BasicProperties.Builder()

.correlationId(corrId).replyTo(replyQueueName).build();

//客户端发送RFC请求

channel.basicPublish("", queueName, props,
"GetUserInfo".getBytes());

//Server返回消息

final BlockingQueue response = new
ArrayBlockingQueue(1);

channel.basicConsume(replyQueueName, true,

new DefaultConsumer(channel) {

@Override

public void handleDelivery(String consumerTag,

Envelope envelope, AMQP.BasicProperties properties,

byte[] body) throws IOException {

System.out.println(properties.getCorrelationId());

if (properties.getCorrelationId().equals(corrId)) {

response.offer(body);

}

}

});

byte[] b = response.take();

System.out.println(new String(b));

channel.close();

connection.close();

}

catch(Exception e)

{

e.printStackTrace();

}

}

}