RPC框架简易实现

package com.jd.rpc;


import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * RpcFramework
 * 包含 RPC服务器+接口代理类
 *
 * @author william.liangf
 */
public class RpcFramework {

    /**
     * 暴露RPC服务
     *
     * @param service 服务实现
     * @param port 服务端口
     * @throws Exception
     */
    public static void export(final Object service, int port) throws Exception {
        if (service == null)
            throw new IllegalArgumentException("service instance == null");
        if (port <= 0 || port > 65535)//端口范围0~65535
            throw new IllegalArgumentException("Invalid port " + port);
        System.out.println("Export service " + service.getClass().getName() + " on port " + port);
        ServerSocket server = new ServerSocket(port);
        for(;;) {
            try {
                final Socket socket = server.accept();//启动服务端的Socket，等待客户端来连接
                new Thread(new Runnable() {//每次连接都启动一个全新的线程
                    @Override
                    public void run() {
                        try {
                            try {
                                ObjectInputStream input = new ObjectInputStream(socket.getInputStream());//获取socket传递过来的数据
                                try {
                                    String methodName = input.readUTF();//接口方法名
                                    Class<?>[] parameterTypes = (Class<?>[])input.readObject();//接口与参数类型
                                    Object[] arguments = (Object[])input.readObject();//具体参数值
                                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());//获取回传output
                                    try {
                                        //通过java的反射，动态执行实现类service的方法
                                        Method method = service.getClass().getMethod(methodName, parameterTypes);
                                        Object result = method.invoke(service, arguments);
                                        //将调用结果回传给调用方
                                        output.writeObject(result);
                                    } catch (Throwable t) {
                                        output.writeObject(t);//关闭
                                    } finally {
                                        output.close();//关闭
                                    }
                                } finally {
                                    input.close();//关闭
                                }
                            } finally {
                                socket.close();//关闭
                            }
                        } catch (Exception e) {
                            e.printStackTrace();
                        }
                    }
                }).start();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * 引用服务，即接口代理类
     *
     * @param <T> 接口泛型
     * @param interfaceClass 接口类型
     * @param host 服务器主机名
     * @param port 服务器端口
     * @return 远程服务
     * @throws Exception
     */
    @SuppressWarnings("unchecked")
    public static <T> T refer(final Class<T> interfaceClass, final String host, final int port) throws Exception {
        if (interfaceClass == null)
            throw new IllegalArgumentException("Interface class == null");
        if (! interfaceClass.isInterface())
            throw new IllegalArgumentException("The " + interfaceClass.getName() + " must be interface class!");
        if (host == null || host.length() == 0)
            throw new IllegalArgumentException("Host == null!");
        if (port <= 0 || port > 65535)
            throw new IllegalArgumentException("Invalid port " + port);
        System.out.println("Get remote service " + interfaceClass.getName() + " from server " + host + ":" + port);
        //创建JDK 动态代理类，作为接口的代理类
        //其中最主要的是在此接口代理类中 需要执行套接字的相关内容，以便发送相关的套接字内容
        //其中最主要的是在代理类中实现套接字请求
        return (T) Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class<?>[] {interfaceClass}, new InvocationHandler() {
            public Object invoke(Object proxy, Method method, Object[] arguments) throws Throwable {
                //套接字连接
                Socket socket = new Socket(host, port);
                try {
                    //对象输出流
                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());
                    try {
                        output.writeUTF(method.getName());//传入参数 方法名称
                        output.writeObject(method.getParameterTypes());//传入参数 参数类型
                        output.writeObject(arguments);//传入参数 参数对象
                        ObjectInputStream input = new ObjectInputStream(socket.getInputStream());//接收RPC服务器回传回来的内容
                        try {
                            Object result = input.readObject();
                            if (result instanceof Throwable) {
                                throw (Throwable) result;
                            }
                            return result;//返回结果对象
                        } finally {
                            input.close();//关闭
                        }
                    } finally {
                        output.close();//关闭
                    }
                } finally {
                    socket.close();//关闭
                }
            }
        });
    }


}

/**
 *  定义接口服务
 *
 * @author william.liangf
 */
public interface HelloService {

    String hello(String name);

}

package com.jd.rpc;

/**
 *接口服务实现类
 *
 * @author william.liangf
 */
public class HelloServiceImpl implements HelloService {

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

}

package com.jd.rpc;


/**
 * RpcProvider
 * RPC 服务提供者 可以理解为生产者
 *
 * @author william.liangf
 */
public class RpcProvider {

    public static void main(String[] args) throws Exception {
        HelloService service = new HelloServiceImpl();
        RpcFramework.export(service, 1234);
    }

}

package com.jd.rpc;


/**
 * RpcConsumer
 * RPC服务调用者 可以理解为消费者
 *
 * @author william.liangf
 */
public class RpcConsumer {

    public static void main(String[] args) throws Exception {
        HelloService service = RpcFramework.refer(HelloService.class, "127.0.0.1", 1234);
        for (int i = 0; i < Integer.MAX_VALUE; i ++) {
            String hello = service.hello("World" + i);
            System.out.println(hello);
            Thread.sleep(1000);
        }
    }

}