RabbitMQ学习笔记5-简单的RPC调用
利用空的queue名字("")让rabbitMQ生成一个唯一的队列名称，同时指定队列是：临时的(auto-delete)、私有的(exclusive)。
在发送的RPC调用消息里设置消息的属性(com.rabbitmq.client.AMQP.BasicProperties)的reply_to字段来传递上面那个随机的队列名称。
基本流程如下：
代码如下：
服务端RpcServer.java
1 package com.yzl.test4; 2 3 import java.io.IOException; 4 5 import org.apache.log4j.Logger; 6 7 import com.rabbitmq.client.AMQP.BasicProperties; 8 import com.rabbitmq.client.Channel; 9 import com.rabbitmq.client.Connection; 10 import com.rabbitmq.client.ConnectionFactory; 11 import com.rabbitmq.client.DefaultConsumer; 12 import com.rabbitmq.client.Envelope; 13 14 /** 15 * 基于rabbitMQ的RPC服务的服务提供者 16 * 消息消费者角色，被动接收消息，然后回复消息 17 * @author: yzl 18 * @date: 2016-10-23 19 */ 20 public class RpcServer { 21 //交换器名称 22 private static final String EXCHANGE_NAME = "rpcDirectExchange"; 23 //client调用的消息存储queue 24 private static final String QUEUE_NAME = "rpcQueue"; 25 //服务提供方的路由key，实际使用场景会是应用的appid或者appName 26 private static final String SERVER_ROUTING_KEY = "rpc_server1"; 27 private static final Logger logger = Logger.getLogger(RpcServer.class); 28 29 /** 30 * @param args 31 * @throws 32 * @throws IOException 33 */ 34 public static void main(String[] args) throws Exception { 35 ConnectionFactory factory = new ConnectionFactory(); 36 factory.setHost("127.0.0.1"); 37 factory.setPort(5672); 38 factory.setVirtualHost("/"); 39 factory.setUsername("guest"); 40 factory.setPassword("guest"); 41 42 Connection connection = factory.newConnection(); 43 final Channel channel = connection.createChannel(); 44 45 //定义RPC的direct的交换器 46 channel.exchangeDeclare(EXCHANGE_NAME, "direct"); 47 //声明接收client调动请求的队列 48 channel.queueDeclare(QUEUE_NAME,false,false,false,null); 49 //绑定队列 50 channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, SERVER_ROUTING_KEY); 51 52 logger.info("服务启动完成，等待接收请求....."); 53 54 //接收client端的请求 55 channel.basicConsume(QUEUE_NAME, false, new DefaultConsumer(channel){ 56 @Override 57 public void handleDelivery(String consumerTag, Envelope envelope, BasicProperties properties, byte[] body) 58 throws IOException { 59 //回复ack响应 60 channel.basicAck(envelope.getDeliveryTag(), false); 61 62 logger.info("收到client调用请求-----------"); 63 String msg = new String(body); 64 logger.info("收到的消息如下:" + msg); 65 String resp = null; 66 67 //模拟解析需要调用的方法 68 if(msg.indexOf("add") != -1){ 69 String parameter = msg.substring(msg.indexOf("(")+1, msg.indexOf(")")); 70 String[] args = parameter.split(","); 71 resp = String.valueOf(add(Integer.valueOf(args[0]), Integer.valueOf(args[1]))); 72 }else{ 73 resp = "method is not found!!"; 74 } 75 logger.info("需要回调的client的queueName:" + properties.getReplyTo()); 76 try { 77 Integer time = new java.util.Random().nextInt(5000); 78 logger.info("休眠" + time + "毫秒"); 79 //随即休眠，模拟服务调用方法正常业务方法耗时 80 Thread.sleep(time); 81 } catch (InterruptedException e) { 82 // TODO Auto-generated catch block 83 e.printStackTrace(); 84 } 85 //发送给默认的direct交换器，路由键为发送方的queueName,默认交换机会把消息转发给此路由键名称的queue 86 channel.basicPublish("", properties.getReplyTo(), properties, (msg + ", resp is：" + resp).getBytes()); 87 logger.info("回复clent完成"); 88 } 89 }); 90 } 91 92 //模拟的server中的方法 93 private static int add(int num1, int num2){ 94 logger.info("call add method, para num1 is :" + num1 + ",num2 is :" + num2); 95 return num1 + num2; 96 } 97 }
客户端
1 package com.yzl.test4; 2 3 import java.io.IOException; 4 import java.util.UUID; 5 import java.util.concurrent.CountDownLatch; 6 import java.util.concurrent.ExecutorService; 7 import java.util.concurrent.Executors; 8 9 import org.apache.log4j.Logger; 10 11 import com.rabbitmq.client.AMQP.BasicProperties; 12 import com.rabbitmq.client.AMQP.Queue; 13 import com.rabbitmq.client.Channel; 14 import com.rabbitmq.client.Connection; 15 import com.rabbitmq.client.ConnectionFactory; 16 import com.rabbitmq.client.DefaultConsumer; 17 import com.rabbitmq.client.Envelope; 18 import com.rabbitmq.client.QueueingConsumer; 19 import com.rabbitmq.client.QueueingConsumer.Delivery; 20 21 /** 22 * 基于rabbitMQ的RPC服务的服务调用者 23 * 消费生产者角色，发送调用请求，然后读取回复 24 * 发送的交换器 和 接收回应的交换器是不同的 25 * @author: yzl 26 * @date: 2016-10-23 27 */ 28 public class RpcClient { 29 //交换器名称 30 private static final String EXCHANGE_NAME = "rpcDirectExchange"; 31 //服务提供方的路由key 32 private static final String SERVER_ROUTING_KEY = "rpc_server1"; 33 34 private static final Logger logger = Logger.getLogger(RpcClient.class); 35 /** 36 * @param args 37 */ 38 public static void main(String[] args) throws Exception { 39 ConnectionFactory factory = new ConnectionFactory(); 40 factory.setHost("127.0.0.1"); 41 factory.setPort(5672); 42 factory.setVirtualHost("/"); 43 factory.setUsername("guest"); 44 factory.setPassword("guest"); 45 46 Connection connection = factory.newConnection(); 47 final Channel channel = connection.createChannel(); 48 49 channel.exchangeDeclare(EXCHANGE_NAME, "direct"); 50 51 int threadCount = 1; 52 53 //使用CountDownLatch控制10个线程一起运行 54 final CountDownLatch cdl = new CountDownLatch(threadCount); 55 56 //生成10个线程同时访问服务 57 ExecutorService pool = Executors.newFixedThreadPool(threadCount); 58 59 for(int i=0; i<threadCount; i++){ 60 final int index = i; 61 pool.submit(new Runnable() { 62 @Override 63 public void run() { 64 try { 65 cdl.await(); 66 67 //Queue.DeclareOk queueDeclare(String queue, boolean durable, boolean exclusive, boolean autoDelete,Map<String, Object> arguments) 68 //默认direct exchange 匿名的、 私有、自动删除 69 Queue.DeclareOk queue = channel.queueDeclare("", false, true, true, null); 70 //获取rabbit帮我们生成的随即的队列名称，来接收服务端返回的数据 71 String queueName = queue.getQueue(); 72 73 final String messageId = UUID.randomUUID().toString(); 74 //定义replyTo属性 和 消息ID 75 BasicProperties props = new BasicProperties.Builder().replyTo(queueName).correlationId(messageId).build(); 76 77 logger.info("发送rpc调用请求，消息index:" + index); 78 79 //发送RPC方法调用 80 channel.basicPublish(EXCHANGE_NAME, SERVER_ROUTING_KEY, props, ("add(" + index + "," + (index+1) + ")").getBytes()); 81 82 logger.info("等待服务器响应"); 83 84 //定义队列式的消费者处理器，之前是用的DefaultConsumer 85 QueueingConsumer consumer = new QueueingConsumer(channel); 86 87 //把消费者处理器和队列对照起来 88 channel.basicConsume(queueName, consumer); 89 90 //这里会堵塞，直到取到值或者超时 91 logger.info("尝试从consumer里取返回的值"); 92 Delivery delivery = consumer.nextDelivery(); 93 //Delivery delivery = consumer.nextDelivery(5000); 94 logger.info("成功取到消息，开始处理"); 95 if(delivery.getProperties().getCorrelationId().equals(messageId)){ 96 logger.info("收到服务器回复-----------"); 97 String msg = new String(delivery.getBody()); 98 logger.info("回复消息id：" + delivery.getProperties().getCorrelationId() + "内容:" + msg); 99 } 100 101 /* 102 //该取消息的方式是异步的，不会堵塞，会导致后面的logger.info先于handleDelivery执行 103 channel.basicConsume(queueName, new DefaultConsumer(channel){ 104 @Override 105 public void handleDelivery(String consumerTag, Envelope envelope, 106 BasicProperties properties, byte[] body) throws IOException { 107 if(properties.getCorrelationId().equals(messageId)){ 108 logger.info("收到服务器回复-----------"); 109 String msg = new String(body); 110 logger.info("回复消息id：" + properties.getCorrelationId() + "内容:" + msg); 111 } 112 } 113 }); 114 */ 115 116 logger.info("消息处理完成"); 117 } catch (Exception e) { 118 e.printStackTrace(); 119 } 120 } 121 }); 122 } 123 for(int i=0; i<threadCount; i++){ 124 cdl.countDown(); 125 } 126 } 127 }
先运行server后运行client，输入如下：
1 2016-10-23 21:22:38,961 [com.yzl.test4.RpcServer]-[INFO] 服务启动完成，等待接收请求..... 2 2016-10-23 21:22:42,414 [com.yzl.test4.RpcServer]-[INFO] 收到client调用请求----------- 3 2016-10-23 21:22:42,414 [com.yzl.test4.RpcServer]-[INFO] 收到的消息如下:add(0,1) 4 2016-10-23 21:22:42,414 [com.yzl.test4.RpcServer]-[INFO] call add method, para num1 is :0,num2 is :1 5 2016-10-23 21:22:42,414 [com.yzl.test4.RpcServer]-[INFO] 需要回调的client的queueName:amq.gen-iek4oYqWiqQ-HU7-i2g6mA 6 2016-10-23 21:22:42,414 [com.yzl.test4.RpcServer]-[INFO] 休眠3999毫秒 7 2016-10-23 21:22:46,415 [com.yzl.test4.RpcServer]-[INFO] 回复clent完成
1 2016-10-23 21:22:42,398 [com.yzl.test4.RpcClient]-[INFO] 发送rpc调用请求，消息index:0 2 2016-10-23 21:22:42,414 [com.yzl.test4.RpcClient]-[INFO] 等待服务器响应 3 2016-10-23 21:22:42,414 [com.yzl.test4.RpcClient]-[INFO] 尝试从consumer里取返回的值 4 2016-10-23 21:22:46,415 [com.yzl.test4.RpcClient]-[INFO] 成功取到消息，开始处理 5 2016-10-23 21:22:46,415 [com.yzl.test4.RpcClient]-[INFO] 收到服务器回复----------- 6 2016-10-23 21:22:46,415 [com.yzl.test4.RpcClient]-[INFO] 回复消息id：1e4b7fb3-1728-41e2-8cac-b13fe88d5a20内容:add(0,1), resp is：1 7 2016-10-23 21:22:46,415 [com.yzl.test4.RpcClient]-[INFO] 消息处理完成
