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netty 案例，netty4.1 高级应用篇三，手写 RPC 框架第三章《RPC 中间件》

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发布于: 2020 年 08 月 22 日

案例介绍

结合上面两章节，本章将实现rpc的基础功能；提供一给rpc中间件jar给生产端和服务端。

技术点；

1、注册中心，生产者在启动的时候需要将本地接口发布到注册中心，我们这里采用redis作为注册中心，随机取数模拟权重。

2、客户端在启动的时候，连接到注册中心，也就是我们的redis。连接成功后将配置的生产者方法发布到注册中心{接口+别名}。

3、服务端配置生产者的信息后，在加载xml时候由中间件生成动态代理类，当发生发放调用时实际则调用了我们代理类的方法，代理里会通过netty的futuer通信方式进行数据交互。



环境准备

1、jdk 1.8.0

2、IntelliJ IDEA Community Edition 2018.3.1 x64

3、windows redis



代码示例

itstack-demo-rpc-03
└── src
    └── main
    │    ├── java
    │    │    └── org.itstack.demo.rpc
    │    │        ├── config
    │    │        ├── domain
    │    │        ├── network	
    │    │        │   ├── client
    │    │        │   │   ├── ClientSocket.java
    │    │        │   │   └── MyClientHandler.java  
    │    │        │   ├── codec
    │    │        │   │   ├── RpcDecoder.java
    │    │        │   │   └── RpcEncoder.java  
    │    │        │   ├── future
    │    │        │   │   ├── SyncWrite.java 	
    │    │        │   │   ├── SyncWriteFuture.java	
    │    │        │   │   ├── SyncWriteMap.java	
    │    │        │   │   └── WriteFuture.java	
    │    │        │   ├── msg
    │    │        │   │   ├── Request.java
    │    │        │   │   └── Response.java 
    │    │        │   ├── server
    │    │        │   │   ├── MyServerHandler.java
    │    │        │   │   └── ServerSocket.java 	
    │    │        │   └── util
    │    │        │ 	  └── SerializationUtil.java 	
    │    │        ├── reflect
    │    │        │   ├── JDKInvocationHandler.java	
    │    │        │   └── JDKProxy.java
    │    │        ├── registry
    │    │        │   └── RedisRegistryCenter.java	
    │    │        └── util	
    │ 	 └── resource
    │        └── META-INF
    │            ├── rpc.xsd
    │            ├── spring.handlers
    │            └── spring.schemas	
	
    └── test
         ├── java
         │   └── org.itstack.demo.test
         │       ├── service
         │       │   ├── impl
         │   	 │   │   └── HelloServiceImpl.java  
         │   	 │   └── HelloService.java
         │       └── ApiTest.java				 
         └── resource  
		     ├── itstack-rpc-center.xml
             ├── itstack-rpc-consumer.xml		 
			 ├── itstack-rpc-provider.xml
			 └── log4j.xml			 




>ConsumerBean.java



package org.itstack.demo.rpc.config.spring.bean;
import com.alibaba.fastjson.JSON;
import io.netty.channel.ChannelFuture;
import org.itstack.demo.rpc.config.ConsumerConfig;
import org.itstack.demo.rpc.domain.RpcProviderConfig;
import org.itstack.demo.rpc.network.client.ClientSocket;
import org.itstack.demo.rpc.network.msg.Request;
import org.itstack.demo.rpc.reflect.JDKProxy;
import org.itstack.demo.rpc.registry.RedisRegistryCenter;
import org.itstack.demo.rpc.util.ClassLoaderUtils;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.util.Assert;
/**
 * http://www.itstack.org
 * create by fuzhengwei on 2019/5/6
 */
public class ConsumerBean<T> extends ConsumerConfig<T> implements FactoryBean {
    private ChannelFuture channelFuture;
    private RpcProviderConfig rpcProviderConfig;
    @Override
    public Object getObject() throws Exception {
        //从redis获取链接
        if (null == rpcProviderConfig) {
            String infoStr = RedisRegistryCenter.obtainProvider(nozzle, alias);
            rpcProviderConfig = JSON.parseObject(infoStr, RpcProviderConfig.class);
        }
        Assert.isTrue(null != rpcProviderConfig);
        //获取通信channel
        if (null == channelFuture) {
            ClientSocket clientSocket = new ClientSocket(rpcProviderConfig.getHost(), rpcProviderConfig.getPort());
            new Thread(clientSocket).start();
            for (int i = 0; i < 100; i++) {
                if (null != channelFuture) break;
                Thread.sleep(500);
                channelFuture = clientSocket.getFuture();
            }
        }
        Assert.isTrue(null != channelFuture);
        Request request = new Request();
        request.setChannel(channelFuture.channel());
        request.setNozzle(nozzle);
        request.setRef(rpcProviderConfig.getRef());
        request.setAlias(alias);
        return (T) JDKProxy.getProxy(ClassLoaderUtils.forName(nozzle), request);
    }
    @Override
    public Class<?> getObjectType() {
        try {
            return ClassLoaderUtils.forName(nozzle);
        } catch (ClassNotFoundException e) {
            return null;
        }
    }
    @Override
    public boolean isSingleton() {
        return true;
    }
}



>ProviderBean.java



package org.itstack.demo.rpc.config.spring.bean;
import com.alibaba.fastjson.JSON;
import org.itstack.demo.rpc.config.ProviderConfig;
import org.itstack.demo.rpc.domain.LocalServerInfo;
import org.itstack.demo.rpc.domain.RpcProviderConfig;
import org.itstack.demo.rpc.registry.RedisRegistryCenter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
/**
 * http://www.itstack.org
 * create by fuzhengwei on 2019/5/6
 */
public class ProviderBean extends ProviderConfig implements ApplicationContextAware {
    private Logger logger = LoggerFactory.getLogger(ProviderBean.class);
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        RpcProviderConfig rpcProviderConfig = new RpcProviderConfig();
        rpcProviderConfig.setNozzle(nozzle);
        rpcProviderConfig.setRef(ref);
        rpcProviderConfig.setAlias(alias);
        rpcProviderConfig.setHost(LocalServerInfo.LOCAL_HOST);
        rpcProviderConfig.setPort(LocalServerInfo.LOCAL_PORT);
        //注册生产者
        long count = RedisRegistryCenter.registryProvider(nozzle, alias, JSON.toJSONString(rpcProviderConfig));
        logger.info("注册生产者：{} {} {}", nozzle, alias, count);
    }
}



>ServerBean.java



package org.itstack.demo.rpc.config.spring.bean;
import org.itstack.demo.rpc.config.ServerConfig;
import org.itstack.demo.rpc.domain.LocalServerInfo;
import org.itstack.demo.rpc.network.server.ServerSocket;
import org.itstack.demo.rpc.registry.RedisRegistryCenter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
/**
 * http://www.itstack.org
 * create by fuzhengwei on 2019/5/6
 */
public class ServerBean extends ServerConfig implements ApplicationContextAware {
    private Logger logger = LoggerFactory.getLogger(ServerBean.class);
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        //启动注册中心
        logger.info("启动注册中心 ...");
        RedisRegistryCenter.init(host, port);
        logger.info("启动注册中心完成 {} {}", host, port);
        //初始化服务端
        logger.info("初始化生产端服务 ...");
        ServerSocket serverSocket = new ServerSocket(applicationContext);
        Thread thread = new Thread(serverSocket);
        thread.start();
        while (!serverSocket.isActiveSocketServer()) {
            try {
                Thread.sleep(500);
            } catch (InterruptedException ignore) {
            }
        }
        logger.info("初始化生产端服务完成 {} {}", LocalServerInfo.LOCAL_HOST, LocalServerInfo.LOCAL_PORT);
    }
}



>MyClientHandler.java



package org.itstack.demo.rpc.network.client;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import org.itstack.demo.rpc.network.future.SyncWriteFuture;
import org.itstack.demo.rpc.network.future.SyncWriteMap;
import org.itstack.demo.rpc.network.msg.Response;
/**
 * http://www.itstack.org
 * create by fuzhengwei on 2019/5/6
 */
public class MyClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object obj) throws Exception {
        Response msg = (Response) obj;
        String requestId = msg.getRequestId();
        SyncWriteFuture future = (SyncWriteFuture) SyncWriteMap.syncKey.get(requestId);
        if (future != null) {
            future.setResponse(msg);
        }
    }
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}



>MyServerHandler.java



package org.itstack.demo.rpc.network.server;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.ReferenceCountUtil;
import org.itstack.demo.rpc.network.msg.Request;
import org.itstack.demo.rpc.network.msg.Response;
import org.itstack.demo.rpc.util.ClassLoaderUtils;
import org.springframework.context.ApplicationContext;
import java.lang.reflect.Method;
/**
 * http://www.itstack.org
 * create by fuzhengwei on 2019/5/6
 */
public class MyServerHandler extends ChannelInboundHandlerAdapter {
    private ApplicationContext applicationContext;
    MyServerHandler(ApplicationContext applicationContext) {
        this.applicationContext = applicationContext;
    }
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object obj) {
        try {
            Request msg = (Request) obj;
            //调用
            Class<?> classType = ClassLoaderUtils.forName(msg.getNozzle());
            Method addMethod = classType.getMethod(msg.getMethodName(), msg.getParamTypes());
            Object objectBean = applicationContext.getBean(msg.getRef());
            Object result = addMethod.invoke(objectBean, msg.getArgs());
            //反馈
            Response request = new Response();
            request.setRequestId(msg.getRequestId());
            request.setResult(result);
            ctx.writeAndFlush(request);
            //释放
            ReferenceCountUtil.release(msg);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }
}



>JDKInvocationHandler.java



package org.itstack.demo.rpc.reflect;
import org.itstack.demo.rpc.network.future.SyncWrite;
import org.itstack.demo.rpc.network.msg.Request;
import org.itstack.demo.rpc.network.msg.Response;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
public class JDKInvocationHandler implements InvocationHandler {
    private Request request;
    public JDKInvocationHandler(Request request) {
        this.request = request;
    }
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        String methodName = method.getName();
        Class[] paramTypes = method.getParameterTypes();
        if ("toString".equals(methodName) && paramTypes.length == 0) {
            return request.toString();
        } else if ("hashCode".equals(methodName) && paramTypes.length == 0) {
            return request.hashCode();
        } else if ("equals".equals(methodName) && paramTypes.length == 1) {
            return request.equals(args[0]);
        }
        //设置参数
        request.setMethodName(methodName);
        request.setParamTypes(paramTypes);
        request.setArgs(args);
        request.setRef(request.getRef());
        Response response = new SyncWrite().writeAndSync(request.getChannel(), request, 5000);
        //异步调用
        return response.getResult();
    }
}



>JDKProxy.java



package org.itstack.demo.rpc.reflect;
import org.itstack.demo.rpc.network.msg.Request;
import org.itstack.demo.rpc.util.ClassLoaderUtils;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
public class JDKProxy {
    public static <T> T getProxy(Class<T> interfaceClass, Request request) throws Exception {
        InvocationHandler handler = new JDKInvocationHandler(request);
        ClassLoader classLoader = ClassLoaderUtils.getCurrentClassLoader();
        T result = (T) Proxy.newProxyInstance(classLoader, new Class[]{interfaceClass}, handler);
        return result;
    }
}



>RedisRegistryCenter.java



package org.itstack.demo.rpc.registry;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;
/**
 * http://www.itstack.org
 * create by fuzhengwei on 2019/5/7
 * redis 模拟RPC注册中心
 */
public class RedisRegistryCenter {
    private static Jedis jedis;   //非切片额客户端连接
    //初始化redis
    public static void init(String host, int port) {
        // 池基本配置
        JedisPoolConfig config = new JedisPoolConfig();
        config.setMaxIdle(5);
        config.setTestOnBorrow(false);
        JedisPool jedisPool = new JedisPool(config, host, port);
        jedis = jedisPool.getResource();
    }
    /**
     * 注册生产者
     *
     * @param nozzle 接口
     * @param alias  别名
     * @param info   信息
     * @return 注册结果
     */
    public static Long registryProvider(String nozzle, String alias, String info) {
        return jedis.sadd(nozzle + "_" + alias, info);
    }
    /**
     * 获取生产者
     * 模拟权重，随机获取
     * @param nozzle 接口名称
     */
    public static String obtainProvider(String nozzle, String alias) {
        return jedis.srandmember(nozzle + "_" + alias);
    }
    public static Jedis jedis() {
        return jedis;
    }
}



>ApiTest.java



public class ApiTest {
    public static void main(String[] args) {
        String[] configs = {"itstack-rpc-center.xml", "itstack-rpc-provider.xml", "itstack-rpc-consumer.xml"};
        new ClassPathXmlApplicationContext(configs);
    }
}



框架，测试结果



2019-....ClassPathXmlApplicationContext:prepareRefresh:510] - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@299a06ac: startup date [Tue May 07 20:19:47 CST 2019]; root of context hierarchy
2019-...ml.XmlBeanDefinitionReader:loadBeanDefinitions:315] - Loading XML bean definitions from class path resource [spring/itstack-rpc-center.xml]
2019-...ml.XmlBeanDefinitionReader:loadBeanDefinitions:315] - Loading XML bean definitions from class path resource [spring/itstack-rpc-provider.xml]
2019-...ml.XmlBeanDefinitionReader:loadBeanDefinitions:315] - Loading XML bean definitions from class path resource [spring/itstack-rpc-consumer.xml]
2019-...upport.DefaultListableBeanFactory:preInstantiateSingletons:577] - Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@7e0b0338: defining beans [consumer_itstack,provider_helloService,consumer_helloService]; root of factory hierarchy
2019-...bean.ServerBean:setApplicationContext:25] - 启动注册中心 ...
2019-...bean.ServerBean:setApplicationContext:27] - 启动注册中心完成 127.0.0.1 6379
2019-...bean.ServerBean:setApplicationContext:30] - 初始化生产端服务 ...
2019-...bean.ServerBean:setApplicationContext:41] - 初始化生产端服务完成 10.13.81.104 22201
2019-...bean.ProviderBean:setApplicationContext:35] - 注册生产者：org.itstack.demo.test.service.HelloService itStackRpc 0



框架应用

为了测试我们写两个测试工程；itstack-demo-rpc-provider、itstack-demo-rpc-consumer



>itstack-demo-rpc-provider 提供生产者接口



itstack-demo-rpc-provider
├── itstack-demo-rpc-provider-export
│   └── src
│        └── main
│            └── java
│                 └── org.itstack.demo.rpc.provider.export
│                     ├── domain 
│                     │   └── Hi.java
│                     └── HelloService.java
│   
└── itstack-demo-rpc-provider-web
    └── src
         └── main
             ├── java
             │    └── org.itstack.demo.rpc.provider.web
			 │	      └── HelloServiceImpl.java
             └── resources
                  └── spring
					  └── spring-itstack-rpc-provider.xml



>HelloService.java



public interface HelloService {
    String hi();
    String say(String str);
    String sayHi(Hi hi);
}



>HelloServiceImpl.java



@Controller("helloService")
public class HelloServiceImpl implements HelloService {
    @Override
    public String hi() {
        return "hi itstack rpc";
    }
    @Override
    public String say(String str) {
        return str;
    }
    @Override
    public String sayHi(Hi hi) {
        return hi.getUserName() + " say：" + hi.getSayMsg();
    }
}



>spring-itstack-rpc-provider.xml



<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:rpc="http://rpc.itstack.org/schema/rpc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
	  http://rpc.itstack.org/schema/rpc http://rpc.itstack.org/schema/rpc/rpc.xsd">
    <!-- 注册中心 -->
    <rpc:server id="rpcServer" host="127.0.0.1" port="6379"/>
    <rpc:provider id="helloServiceRpc" nozzle="org.itstack.demo.rpc.provider.export.HelloService"
                  ref="helloService" alias="itstackRpc"/>
</beans>



>itstack-demo-rpc-consumer 提供消费者调用



itstack-demo-rpc-consumer
└── src
     ├── main
     │   ├── java    
     │   └── resources
     │       └── spring
	 │	         └── spring-itstack-rpc-consumer.xml
     │   
	 └── test
         └── java
             └── org.itstack.demo.test
                 └── ConsumerTest.java



>spring-itstack-rpc-consumer.xml



<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:rpc="http://rpc.itstack.org/schema/rpc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
	  http://rpc.itstack.org/schema/rpc http://rpc.itstack.org/schema/rpc/rpc.xsd">
    <!-- 注册中心 -->
    <rpc:server id="consumer_itstack" host="127.0.0.1" port="6379"/>
    <rpc:consumer id="helloService" nozzle="org.itstack.demo.rpc.provider.export.HelloService" alias="itstackRpc"/>
</beans>



>ConsumerTest.java



@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("/spring-config.xml")
public class ConsumerTest {
    @Resource(name = "helloService")
    private HelloService helloService;
    @Test
    public void test() {
        
        String hi = helloService.hi();
        System.out.println("测试结果：" + hi);
        String say = helloService.say("hello world");
        System.out.println("测试结果：" + say);
        Hi hiReq = new Hi();
        hiReq.setUserName("付栈");
        hiReq.setSayMsg("付可敌国，栈无不胜");
        String hiRes = helloService.sayHi(hiReq);
        System.out.println("测试结果：" + hiRes);
    }
}



应用，测试结果 测试时启动redis



启动ProviderTest Redis中的注册数据



redis 127.0.0.1:6379> srandmember org.itstack.demo.rpc.provider.export.HelloService_itstackRpc
"{\"alias\":\"itstackRpc\",\"host\":\"10.13.81.104\",\"nozzle\":\"org.itstack.demo.rpc.provider.export.HelloService\",\"port\":22201,\"ref\":\"helloService\"}"
redis 127.0.0.1:6379>



执行ConsumerTest中的单元测试方法



log4j:WARN No appenders could be found for logger (org.springframework.test.context.junit4.SpringJUnit4ClassRunner).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
测试结果：hi itstack rpc
测试结果：hello world
测试结果：付栈 say：付可敌国，栈无不胜
Process finished with exit code 0

------------



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发布于: 2020 年 08 月 22 日 阅读数: 29

版权声明: 本文为 InfoQ 作者【小傅哥】的原创文章。

原文链接:【http://xie.infoq.cn/article/f374236367227cd6f5160d13d】。文章转载请联系作者。

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netty案例，netty4.1高级应用篇三，手写RPC框架第三章《RPC中间件》