rabbitMQ学习笔记(七) RPC 远程过程调用

当客户端想要调用服务器的某个方法来完成某项功能时，就可以使用rabbitMQ支持的PRC服务。

其实RPC服务与普通的收发消息的区别不大， RPC的过程其实就是   

客户端向服务端定义好的Queue发送消息，其中携带的消息就应该是服务端将要调用的方法的参数 ，并使用Propertis告诉服务端将结果返回到指定的Queue。

示例：

 package com.zf.rabbitmq07;

 import java.io.IOException;

 import com.rabbitmq.client.AMQP.BasicProperties;
 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.Connection;
 import com.rabbitmq.client.ConnectionFactory;
 import com.rabbitmq.client.ConsumerCancelledException;
 import com.rabbitmq.client.QueueingConsumer;
 import com.rabbitmq.client.QueueingConsumer.Delivery;
 import com.rabbitmq.client.ShutdownSignalException;

 public class RPCServer {

     public static final String RPC_QUEUE_NAME = "rpc_queue";

     public static String sayHello(String name){
         return "hello " + name ;
     }

     public static void main(String[] args) throws IOException, ShutdownSignalException, ConsumerCancelledException, InterruptedException {

         ConnectionFactory connFac = new ConnectionFactory() ;
         connFac.setHost("localhost");

         Connection conn = connFac.newConnection() ;

         Channel channel = conn.createChannel() ;

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

         QueueingConsumer consumer = new QueueingConsumer(channel);

         channel.basicConsume(RPC_QUEUE_NAME, false , consumer) ;

         while(true){
             System.out.println("服务端等待接收消息..");
             Delivery deliver = consumer.nextDelivery() ;
             System.out.println("服务端成功收到消息..");
             BasicProperties props =  deliver.getProperties() ;

             String message = new String(deliver.getBody() , "UTF-8") ;

             String responseMessage = sayHello(message) ;

             BasicProperties responseProps = new BasicProperties.Builder()
             .correlationId(props.getCorrelationId())
             .build() ;

             //将结果返回到客户端Queue
             channel.basicPublish("", props.getReplyTo() , responseProps , responseMessage.getBytes("UTF-8") ) ;

             //向客户端确认消息
             channel.basicAck(deliver.getEnvelope().getDeliveryTag(), false);
             System.out.println("服务端返回消息完成..");
         }

     }

 }

 package com.zf.rabbitmq07;

 import java.io.IOException;
 import java.util.UUID;

 import com.rabbitmq.client.Channel;
 import com.rabbitmq.client.Connection;
 import com.rabbitmq.client.ConnectionFactory;
 import com.rabbitmq.client.ConsumerCancelledException;
 import com.rabbitmq.client.QueueingConsumer;
 import com.rabbitmq.client.AMQP.BasicProperties;
 import com.rabbitmq.client.QueueingConsumer.Delivery;
 import com.rabbitmq.client.ShutdownSignalException;

 public class RPCClient {

     public static final String RPC_QUEUE_NAME = "rpc_queue";

     public static void main(String[] args) throws IOException, ShutdownSignalException, ConsumerCancelledException, InterruptedException {

         ConnectionFactory connFac = new ConnectionFactory() ;
         connFac.setHost("localhost");
         Connection conn = connFac.newConnection() ;
         Channel channel = conn.createChannel() ;

         //响应QueueName ，服务端将会把要返回的信息发送到该Queue
         String responseQueue = channel.queueDeclare().getQueue() ;

         String correlationId = UUID.randomUUID().toString() ;

         BasicProperties props = new BasicProperties.Builder()
         .replyTo(responseQueue)
         .correlationId(correlationId)
         .build();

         String message = "is_zhoufeng";
         channel.basicPublish( "" , RPC_QUEUE_NAME , props ,  message.getBytes("UTF-8"));

         QueueingConsumer consumer = new QueueingConsumer(channel)   ;

         channel.basicConsume( responseQueue , consumer) ;

         while(true){

             Delivery delivery = consumer.nextDelivery() ;

             if(delivery.getProperties().getCorrelationId().equals(correlationId)){
                 String result = new String(delivery.getBody()) ;
                 System.out.println(result);
             }

         }
     }

 }

转载： http://blog.csdn.net/is_zhoufeng/article/details/10072819