手写一个简单的RPC框架

野性酷女 2024-05-24 01:31 187阅读 0赞

> 学习RPC框架，由繁化简，了解其本质原理

#### 文章目录 ####

*  项目简介
 *   *  什么是RPC？
     *  项目模块
 *  项目代码
 *   *  common模块
     *  client模块
     *  server模块
     *  framework模块
     *  测试

## 项目简介 ##

### 什么是RPC？ ###

RPC（Remote Procedure Call）即远程过程调用，不同于本地调用，RPC是指调用远端机器的函数或方法，且不需要关心底层的调用细节，如网络协议和传输协议等，对于调用者来说，和调用本地方法没有什么区别。

### 项目模块 ###

1.  common模块：定义了用户接口和实体类User
2.  client模块：调用RPC框架的代理类，获取结果
3.  server模块：

*  实现common的接口，把实现类注册到注册中心中
 *  调用RpcServer开启socket
 *  根据RpcRequest类的信息，获取到注册中心的实现类
 *  执行方法，返回结果，通过socket返回

1.  Rpc framework

*  注册中心
 *  RpcRequest，装载类的信息
 *  RpcServer：创建socket，接受客户端的请求

![在这里插入图片描述][eaad624cc5e743da8646556d4611ce6a.jpeg_pic_center]

## 项目代码 ##

### common模块 ###

实体类和定义的接口

package com.rpc.common;
    
    import lombok.AllArgsConstructor;
    import lombok.Builder;
    import lombok.Data;
    import lombok.NoArgsConstructor;
    
    import java.io.Serializable;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 10:37
     * @Desc: 网络中传输的信息
     */
    @Data
    @AllArgsConstructor
    @NoArgsConstructor
    @Builder
    public class User implements Serializable {
        
    
        private Integer id;
    
        private String name;
    
        private Integer age;
    
        private int sex;
    }

package com.rpc.common;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 10:38
     * @Desc:
     */
    public interface IUserService {
        
        User getById(Integer id);
    
        User getUsername(String userName);
    }

### client模块 ###

package com.rpc.client;
    
    import com.rpc.common.IUserService;
    import com.rpc.framework.proxy.RpcProxy;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 11:39
     * @Desc:
     */
    public class Client {
        
        public static void main(String[] args) {
        
            RpcProxy rpcProxy = new RpcProxy();
            IUserService productService = (IUserService) rpcProxy.remoteCall("localhost", 10000, IUserService.class);
            System.out.println("productService = " + productService.getById(10));
        }
    }

### server模块 ###

package com.rpc.server;
    
    import com.rpc.common.IUserService;
    import com.rpc.framework.Registry;
    import com.rpc.framework.RpcServer;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 11:37
     * @Desc:
     * https://www.cnblogs.com/fantongxue/p/16004920.html
     */
    public class Server {
        
        /**
         * 把接口和实现类注册到RPC的注册中心，然后通过RPC的RPCServer开启一个serversocket，监听某一个端口。
         * @param args
         */
        public static void main(String[] args) {
        
            Registry.put(IUserService.class.getName(), UserServiceImpl.class);
            new RpcServer().provide(10000);
        }
    }

package com.rpc.server;
    
    import com.rpc.common.User;
    import com.rpc.common.IUserService;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 11:35
     * @Desc:
     */
    public class UserServiceImpl implements IUserService {
        
        @Override
        public User getById(Integer id) {
        
            return User.builder()
                    .id(id)
                    .name("yangmiao")
                    .age(100)
                    .sex(1)
                    .build();
        }
    
        @Override
        public User getUsername(String userName) {
        
            return User.builder()
                    .name(userName)
                    .build();
        }
    }

### framework模块 ###

package com.rpc.framework;
    
    import java.util.HashMap;
    import java.util.concurrent.locks.Lock;
    import java.util.concurrent.locks.ReadWriteLock;
    import java.util.concurrent.locks.ReentrantReadWriteLock;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 10:39
     * @Desc: 注册中心
     */
    public class Registry {
        
        private final static HashMap<String, Class> map = new HashMap<>();
        private final static ReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    
        /**
         * 读缓存
         * @param key
         * @return
         */
        public static Class get(String key){
        
            // 读锁
            Lock writeLock = readWriteLock.writeLock();
            // 写锁
            Lock readLock = readWriteLock.readLock();
    
            Class v = null;
            readLock.lock();
            try {
        
                v = map.get(key);
            }finally {
        
                readLock.unlock();
            }
            if (v != null){
        
                return v;
            }
            // 缓存中不存在
            writeLock.lock();
            try {
        
                v = map.get(key);
                if (v==null){
        
                    // 1.查询数据库
                    // 2.写入缓存
                    map.put(key,v);
                }
            }finally {
        
                writeLock.unlock();
            }
            return v;
        }
    
        /**
         * 写缓存
         * @param key
         * @param value
         * @return
         */
        public static Class put(String key, Class value){
        
            Lock writeLock = readWriteLock.writeLock();
            writeLock.lock();
            try {
        
                return map.put(key,value);
            }finally {
        
                writeLock.unlock();
            }
        }
    
        public static boolean containsKey(String key){
        
            return map.containsKey(key);
        }
    
    }

package com.rpc.framework;
    
    import lombok.Data;
    
    import java.io.Serializable;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 10:41
     * @Desc:
     */
    @Data
    public class RpcRequest implements Serializable {
        
    
        private String className;
    
        private String methodName;
    
        private Class[] types;
    
        private Object[] params;
    
    }

package com.rpc.framework;
    
    
    import java.io.IOException;
    import java.net.ServerSocket;
    import java.net.Socket;
    import java.util.concurrent.ExecutorService;
    import java.util.concurrent.Executors;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 10:42
     * @Desc:
     */
    public class RpcServer {
        
        /**
         * 创建线程池
         */
        private ExecutorService executors = Executors.newFixedThreadPool(5);
    
        public void provide(int port){
        
            try {
        
                ServerSocket serverSocket = new ServerSocket(port);
                while (true){
        
                    Socket socket = serverSocket.accept();
                    executors.execute(new ProcessHandler(socket));
                }
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }
    }

package com.rpc.framework;
    
    import java.io.IOException;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    import java.lang.reflect.InvocationTargetException;
    import java.lang.reflect.Method;
    import java.net.Socket;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 10:50
     * @Desc: 处理服务端逻辑
     */
    public class ProcessHandler implements Runnable {
        
        private Socket socket;
    
        public ProcessHandler(Socket socket) {
        
            this.socket = socket;
        }
    
        @Override
        public void run() {
        
            ObjectInputStream objectInputStream = null;
            ObjectOutputStream objectOutputStream = null;
    
            try {
        
                objectInputStream = new ObjectInputStream(socket.getInputStream());
                RpcRequest rpcRequest = (RpcRequest) objectInputStream.readObject();
    
                Class clazz = null;
                // 判断是否存在于注册中心中
                if (Registry.containsKey(rpcRequest.getClassName())){
        
                    clazz = Registry.get(rpcRequest.getClassName());
                }
                Method method = clazz.getMethod(rpcRequest.getMethodName(), rpcRequest.getTypes());
                Object result = method.invoke(clazz.newInstance(), rpcRequest.getParams());
    
                // 返回结果
                objectOutputStream = new ObjectOutputStream(socket.getOutputStream());
                objectOutputStream.writeObject(result);
                objectOutputStream.flush();
    
            } catch (IOException e) {
        
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
        
                e.printStackTrace();
            } catch (NoSuchMethodException e) {
        
                e.printStackTrace();
            } catch (InvocationTargetException e) {
        
                e.printStackTrace();
            } catch (IllegalAccessException e) {
        
                e.printStackTrace();
            } catch (InstantiationException e) {
        
                e.printStackTrace();
            }finally {
        
                try {
        
                    if (objectInputStream !=null){
        
                        objectInputStream.close();
                    }
                    if (objectOutputStream !=null){
        
                        objectOutputStream.close();
                    }
                }catch (IOException e){
        
                    e.printStackTrace();
                }
    
            }
        }
    }

代理

package com.rpc.framework.proxy;
    
    import java.lang.reflect.InvocationHandler;
    import java.lang.reflect.Proxy;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 11:18
     * @Desc: 创建动态代理
     */
    public class RpcProxy<T> {
        
    
        public T remoteCall(String host,int port,Class clazz){
        
            return (T) Proxy.newProxyInstance(
                    clazz.getClassLoader(),
                    (Class<?>[]) new Class[]{
        clazz},
                    new RemoteInvocationHandler(host,port,clazz)
            );
        }
    }

package com.rpc.framework.proxy;
    
    import com.rpc.framework.RpcRequest;
    
    import java.io.IOException;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    import java.lang.reflect.InvocationHandler;
    import java.lang.reflect.Method;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    /**
     * @Author: Yangmiao
     * @Date: 2023/2/8 11:22
     * @Desc: 代理类执行的逻辑
     */
    public class RemoteInvocationHandler implements InvocationHandler {
        
    
        private String host;
        private int port;
        private Class clazz;
    
        public RemoteInvocationHandler(String host,int port,Class clazz){
        
            this.host = host;
            this.port = port;
            this.clazz = clazz;
        }
    
        @Override
        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        
            RpcRequest rpcRequest = new RpcRequest();
    
            rpcRequest.setClassName(clazz.getName());
            rpcRequest.setMethodName(method.getName());
            rpcRequest.setTypes(method.getParameterTypes());
            rpcRequest.setParams(args);
    
            ObjectOutputStream objectOutputStream = null;
            ObjectInputStream objectInputStream = null;
    
            try {
        
                Socket socket = new Socket(host,port);
                // 发送消息
                objectOutputStream = new ObjectOutputStream(socket.getOutputStream());
                objectOutputStream.writeObject(rpcRequest);
                objectOutputStream.flush();
    
                // 接受结果
                objectInputStream = new ObjectInputStream(socket.getInputStream());
                Object readObject = objectInputStream.readObject();
                return readObject;
            }catch (Exception e){
        
                e.printStackTrace();
            }finally {
        
                try {
        
                    if (objectInputStream !=null){
        
                        objectInputStream.close();
                    }
                    if (objectOutputStream!=null){
        
                        objectOutputStream.close();
                    }
                }catch (IOException e){
        
                    e.printStackTrace();
                }
            }
            return null;
        }
    }

### 测试 ###

![在这里插入图片描述][965e247947654e6aa574bff297316890.jpeg_pic_center]  
![在这里插入图片描述][ee08289ffcff4eb09eea40e4d0bf4147.jpeg_pic_center]

[eaad624cc5e743da8646556d4611ce6a.jpeg_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/05/24/dcf5903cc10c4a1abc469583d758b7d2.jpeg
[965e247947654e6aa574bff297316890.jpeg_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/05/24/1e55154ed81e4540b7ab95faf53923ab.jpeg
[ee08289ffcff4eb09eea40e4d0bf4147.jpeg_pic_center]: https://image.dandelioncloud.cn/pgy_files/images/2024/05/24/bf39bd6936e842b2a27c30b9d348da79.jpeg