package com.yhouse.modules.daos;

public interface IUserDao {
  public String getUserName();
}

package com.yhouse.modules.daos;

import java.lang.reflect.Proxy;
/**
 * 创建代理
 * @author clonen.cheng
 *
 */
public class Invoker {
  
  
  public Object getInstance(Class<?> cls){    
    MethodProxy invocationHandler = new MethodProxy();    
    Object newProxyInstance = Proxy.newProxyInstance( 
        cls.getClassLoader(), 
        new Class[] { cls }, 
        invocationHandler); 
    return (Object)newProxyInstance;
  }
}

package com.yhouse.modules.daos;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

public class MethodProxy implements InvocationHandler {

  @Override
  public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {    
    //如果传进来是一个已实现的具体类（本次演示略过此逻辑)
    if (Object.class.equals(method.getDeclaringClass())) { 
      try { 
        return method.invoke(this, args); 
      } catch (Throwable t) { 
        t.printStackTrace(); 
      } 
    //如果传进来的是一个接口（核心)
    } else { 
      return run(method, args); 
    } 
    return null;
  }
  
  /**
   * 实现接口的核心方法 
   * @param method
   * @param args
   * @return
   */
  public Object run(Method method,Object[] args){ 
    //TODO     
    //如远程http调用
    //如远程方法调用（rmi)
    //....
    return "method call success!";
  } 

}

package com.yhouse.modules.daos;

public class ProxyTest {

  
  public static void main(String[] args) {
    IUserDao invoker=(IUserDao)new Invoker().getInstance(IUserDao.class);
    System.out.println(invoker.getUserName());
  }

}

package com.markliu.remote.service;
/**
 * Service接口。代理类和被代理类抖需要实现该接口
 */
public interface Service {
  public String getService(String name, int number);
}

package com.markliu.remote.serviceimpl;
import com.markliu.remote.service.Service;
/**
 * 服务器端目标业务类，被代理对象
 */
public class RemoteService implements Service {
  @Override
  public String getService(String name, int number) {
    return name + ":" + number;
  }
}

package com.markliu.local.bean;
import java.io.Serializable;
/**
 * 请求的javabean
 */
public class Call implements Serializable{
  private static final long serialVersionUID = 5386052199960133937L;
  private String className; // 调用的类名或接口名
  private String methodName; // 调用的方法名
  private Class<?>[] paramTypes; // 方法参数类型
  private Object[] params; // 调用方法时传入的参数值
  /**
   * 表示方法的执行结果 如果方法正常执行,则 result 为方法返回值,
   * 如果方法抛出异常,那么 result 为该异常。
   */
  private Object result;
  public Call() {}
  public Call(String className, String methodName, Class<?>[] paramTypes, Object[] params) {
    this.className = className;
    this.methodName = methodName;
    this.paramTypes = paramTypes;
    this.params = params;
  }
  // 省略了get和set方法
}

package com.markliu.local.service;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import com.markliu.local.bean.Call;

public class ServiceInvocationHandler implements InvocationHandler {

  private Class<?> classType;
  private String host;
  private Integer port;

  public Class<?> getClassType() {
    return classType;
  }
  public ServiceInvocationHandler(Class<?> classType, String host, Integer port) {
    this.classType = classType;
    this.host = host;
    this.port = port;
  }
  @Override
  public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {

    // 封装请求信息
    Call call = new Call(classType.getName(), method.getName(), method.getParameterTypes(), args);
    // 创建链接
    Connector connector = new Connector();
    connector.connect(host, port);
    // 发送请求
    connector.sendCall(call);
    // 获取封装远程方法调用结果的对象
    connector.close();
    Object returnResult = call.getResult();
    return returnResult;
  }
}

package com.markliu.local.service;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;

/**
 * 动态创建RemoteService代理类的工厂
 */
public class RemoteServiceProxyFactory {

  public static Object getRemoteServiceProxy(InvocationHandler h) {
    Class<?> classType = ((ServiceInvocationHandler) h).getClassType();
    // 获取动态代理类
    Object proxy = Proxy.newProxyInstance(classType.getClassLoader(), 
        new Class[]{classType}, h);
    return proxy;
  }
}

package com.markliu.local.service;
// 省略import

/**
 * 负责创建链接
 */
public class Connector {
  private Socket linksocket;
  private InputStream in;
  private ObjectInputStream objIn;
  private OutputStream out;
  private ObjectOutputStream objOut;

  public Connector(){}
  /**
   * 创建链接
   */
  public void connect(String host, Integer port) throws UnknownHostException, IOException {
    linksocket = new Socket(host, port);
    in = linksocket.getInputStream();
    out = linksocket.getOutputStream();
    objOut = new ObjectOutputStream(out);
    objIn = new ObjectInputStream(in);
  }
  /**
   * 发送请求call对象
   */
  public void sendCall(Call call) throws IOException {
    objOut.writeObject(call);
  }
  /**
   * 获取请求对象
   */
  public Call receive() throws ClassNotFoundException, IOException {
    return (Call) objIn.readObject();
  }
  /**
   * 简单处理关闭链接
   */
  public void close() {
    try {
      linksocket.close();
      objIn.close();
      objOut.close();
      in.close();
      out.close();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

package com.markliu.remote.main;
// 省略import

public class RemoteServer {

  private Service remoteService;
  public RemoteServer() {
    remoteService = new RemoteService();
  }
  public static void main(String[] args) throws Exception {
    RemoteServer server = new RemoteServer();
    System.out.println("远程服务器启动......DONE!");
    server.service();
  }

  public void service() throws Exception {
    @SuppressWarnings("resource")
    ServerSocket serverSocket = new ServerSocket(8001);
    while (true) {
        Socket socket = serverSocket.accept();
        InputStream in = socket.getInputStream();
        ObjectInputStream objIn = new ObjectInputStream(in);
        OutputStream out = socket.getOutputStream();
        ObjectOutputStream objOut = new ObjectOutputStream(out);
        // 对象输入流读取请求的call对象
        Call call = (Call) objIn.readObject();
        System.out.println("客户端发送的请求对象：" + call);
        call = getCallResult(call);
        // 发送处理的结果回客户端
        objOut.writeObject(call);
        objIn.close();
        in.close();
        objOut.close();
        out.close();
        socket.close();
    }
  }

  /**
   * 通过反射机制调用call中指定的类的方法，并将返回结果设置到原call对象中
   */
  private Call getCallResult(Call call) throws Exception {
    String className = call.getClassName();
    String methodName = call.getMethodName();
    Object[] params = call.getParams();
    Class<?>[] paramsTypes = call.getParamTypes();

    Class<?> classType = Class.forName(className);
    // 获取所要调用的方法
    Method method = classType.getMethod(methodName, paramsTypes);
    Object result = method.invoke(remoteService, params);
    call.setResult(result);
    return call;
  }
}

package com.markliu.local.main;
import java.lang.reflect.InvocationHandler;
import com.markliu.local.service.RemoteServiceProxyFactory;
import com.markliu.local.service.ServiceInvocationHandler;
import com.markliu.remote.service.Service;

public class LocalClient {
  public static void main(String[] args) {
    String host = "127.0.0.1";
    Integer port = 8001;
    Class<?> classType = com.markliu.remote.service.Service.class;
    InvocationHandler h = new ServiceInvocationHandler(classType, host, port);
    Service serviceProxy = (Service) RemoteServiceProxyFactory.getRemoteServiceProxy(h);
    String result = serviceProxy.getService("SunnyMarkLiu", 22);
    System.out.println("调用远程方法getService的结果：" + result);
  }
}