package com.alibaba.study.rpc.framework;  

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; 

/**

 * 自行实现一个简易RPC框架

 * @author wangwei03

 */

public class RpcFramework {  

    /**

     * 暴露服务

     *

     * @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)

            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();

                new Thread(new Runnable() {

                    @Override

                    public void run() {

                        try {

                            try {

                                ObjectInputStream input = new ObjectInputStream(socket.getInputStream());

                                try {

                                    String methodName = input.readUTF();

                                    Class<?>[] parameterTypes = (Class<?>[])input.readObject();

                                    Object[] arguments = (Object[])input.readObject();

                                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());

                                    try {

                                        Method method = service.getClass().getMethod(methodName, parameterTypes);

                                        Object result = method.invoke(service, arguments);

                                        output.writeObject(result);

                                    } catch (Throwable t) {

                                        output.writeObject(t);

                                    } finally {

                                        output.close();

                                    }

                                } finally {

                                    input.close();

                                }

                            } finally {

                                socket.close();

                            }

                        } catch (Exception e) {

                            e.printStackTrace();

                        }

                    }

                }).start();

            } catch (Exception e) {

                e.printStackTrace();

            }

        }

    }  

    /**

     * 引用服务

     *

     * @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);

        return (T) Proxy.newProxyInstance(interfaceClass.getClassLoader(), new Class<?>[] {interfaceClass}, new InvocationHandler() {

            public Object invoke(Object proxy, Method method, Object[] arguments) throws Throwable {

                Socket socket = new Socket(host, port);

                try {

                    ObjectOutputStream output = new ObjectOutputStream(socket.getOutputStream());

                    try {

                        output.writeUTF(method.getName());

                        output.writeObject(method.getParameterTypes());

                        output.writeObject(arguments);

                        ObjectInputStream input = new ObjectInputStream(socket.getInputStream());

                        try {

                            Object result = input.readObject();

                            if (result instanceof Throwable) {

                                throw (Throwable) result;

                            }

                            return result;

                        } finally {

                            input.close();

                        }

                    } finally {

                        output.close();

                    }

                } finally {

                    socket.close();

                }

            }

        });

    }  

}  

package com.alibaba.study.rpc.test;

/**

 * HelloService

 * 定义服务接口

 * @author william.liangf

 */

public interface HelloService {

    String hello(String name);

}

package com.alibaba.study.rpc.test;  

/**

 * HelloServiceImpl

 * 实现服务

 * @author william.liangf

 */

public class HelloServiceImpl implements HelloService {  

    public String hello(String name) {

        return "Hello " + name;

    }  

}  

package com.alibaba.study.rpc.test;  

import com.alibaba.study.rpc.framework.RpcFramework;  

/**

 * RpcProvider

 * 暴露服务

 * @author william.liangf

 */

public class RpcProvider {  

    public static void main(String[] args) throws Exception {

        HelloService service = new HelloServiceImpl();

        RpcFramework.export(service, 1234);

    }  

}  

package com.alibaba.study.rpc.test;  

import com.alibaba.study.rpc.framework.RpcFramework;  

/**

 * RpcConsumer

 * 引用服务

 * @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);

        }

    }  

}