Java远程方法调用中动态代理类的使用

参考：http://book.youkuaiyun.com/bookfiles/269/10026911928.shtml
客户端 和 服务端公用文件
share
    |__call
    |       |__Call.java
    |__service
             |__HelloService.java
客户端代码
locale
    |__client
             |__SimpleClient.java
             |__ProxyFactory.java
             |__TcpConnector.java
服务端代码
remote
     |__server
     |        |__SimpleServer.java
     |__service
              |__HelloServiceImpl.java
程序实现目标
    客户端通过动态代理类调用服务端HelloServiceImpl.java 中的方法

 

// share.call.Call.java
package share.call;

import java.io.Serializable;

/**
 *@date 2010-3-13 下午04:32:04
 *@author dycc
 *@file share.call.Call.java
 */
public class Call implements Serializable{
	/**
     * 
     */
    private static final long serialVersionUID = 1L;
	private String className;
	private String methodName;
	@SuppressWarnings(value="unchecked")
	private Class[] paramTypes;
	private Object[] params;
	private Object result;
	
	public Call(){
	}
	@SuppressWarnings(value="unchecked")
	public Call(String className,String methodName,
			Class[] paramTypes,Object[] params){
		this.className = className;
		this.methodName = methodName;
		this.paramTypes = paramTypes;
		this.params = params;
	}
	public String getClassName() {
    	return className;
    }
	public void setClassName(String className) {
    	this.className = className;
    }
	public String getMethodName() {
    	return methodName;
    }
	public void setMethodName(String methodName) {
    	this.methodName = methodName;
    }
	@SuppressWarnings(value="unchecked")
	public Class[] getParamTypes() {
    	return paramTypes;
    }
	@SuppressWarnings(value="unchecked")
	public void setParamTypes(Class[] paramTypes) {
    	this.paramTypes = paramTypes;
    }
	public Object[] getParams() {
    	return params;
    }
	public void setParams(Object[] params) {
    	this.params = params;
    }
	public Object getResult() {
    	return result;
    }
	public void setResult(Object result) {
    	this.result = result;
    }
	public String toString(){
		StringBuffer sb = new StringBuffer();
		sb.append("{className=" + className);
		sb.append(",methodName=" + methodName);
		sb.append(",result=" + result);
		sb.append("}");
		return sb.toString();
	}
}

// share.service.HelloService.java
package share.service;

import java.util.Date;

/**
 *@date 2010-3-13 下午04:29:29
 *@author dycc
 *@file share.service.HelloService.java
 */
public interface HelloService {
	public String echo(String msg);
	public Date getTime();
}

// locale.client.SimpleClient.java
package locale.client;

import share.service.HelloService;

/**
 *@date 2010-3-13 下午04:58:48
 *@author dycc
 *@file locale.client.SimpleClient.java
 */
public class SimpleClient {
	/**
	 * 通过代理类调用远程方法
	 */
	public void invoke(){
		HelloService hello = (HelloService)ProxyFactory.getProxy(
				HelloService.class,"remote.service.HelloServiceImpl",
				"localhost", 8002);
		String result = hello.echo("music");
		System.out.println("result=" + result);
	}
	
	public static void main(String[] args){
		SimpleClient client = new SimpleClient();
		client.invoke();
	}
}

// locale.client.ProxyFactory.java
package locale.client;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.rmi.RemoteException;

import share.call.Call;

/**
 *@date 2010-3-13 下午08:21:01
 *@author dycc
 *@file locale.client.ProxyFactory.java
 */
public class ProxyFactory {
	/**
	 * 获取动态代理类
	 * @param classType 接口
	 * @param className 实现类名称 
	 * @param ip        ip 地址
	 * @param port      端口
	 * @return
	 */
	@SuppressWarnings(value="unchecked")
	public static Object getProxy(Class classType,
			final String className,
			final String ip,final int port){
		// start
		InvocationHandler handler = new InvocationHandler(){
			public Object invoke(Object proxy, Method method, Object[] args)
			        throws Throwable {
				System.out.println("--- before " + method.getName() + "---");
			    TcpConnector connector = new TcpConnector(ip, port);
			    Call call = new Call(className,method.getName(),
			    		method.getParameterTypes(),args);
			    call = (Call)connector.invoke(call);
			    Object result = call.getResult();
			    if(result instanceof Throwable){
			    	return new RemoteException(method.getName() + "invoke failed",
			    			(Throwable)result);
			    }
			    System.out.println("--- after " + method.getName() + "---");
			    connector.close();
			    return result;
			}
		};
		return Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
				new Class[]{classType}, handler);
	}
}

// locale.client.TcpConnector.java
package locale.client;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;

/**
 *@date 2010-3-13 下午08:25:04
 *@author dycc
 *@file locale.client.TcpConnector.java
 */
public class TcpConnector {
	private Socket socket;
	private ObjectInputStream in;
	private ObjectOutputStream out;
	/**
	 * 构造器
	 * @param ip
	 * @param port
	 * @throws IOException
	 */
	public TcpConnector(String ip,int port)throws IOException{
		socket = new Socket(ip,port);
	}
	/**
	 * 调用远程方法
	 * @param obj
	 * @throws IOException
	 */
	public Object invoke(Object obj)throws IOException,ClassNotFoundException{
		if(out == null){
			out = new ObjectOutputStream(socket.getOutputStream());
		}
		out.writeObject(obj);
		out.flush();
		if(in == null){
			in = new ObjectInputStream(socket.getInputStream());
		}
		return in.readObject();
	}
	/**
	 * 关闭连接
	 */
	public void close(){
		try{
			if(in != null){
				in.close();
			}
			if(out != null){
				out.close();
			}
			if(socket != null){
				socket.close();
			}
		} catch(Exception e){
		}
	}
}

// remote.server.SimpleServer.java
package remote.server;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Method;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.Map;

import share.call.Call;


/**
 *@date 2010-3-13 下午04:38:44
 *@author dycc
 *@file remote.server.SimpleServer.java
 */
public class SimpleServer {
	private Map<String,Object> map_objs = new HashMap<String,Object>();
	private ObjectInputStream in;
	private ObjectOutputStream out;
	/**
	 * 服务端在 8002 端口监听客户端请求
	 * @throws IOException
	 */
	public void service()throws IOException{
		ServerSocket server_socket = new ServerSocket(8002);
		System.out.println("----- server started. -----");
		while(true){
			try{
    			Socket socket = server_socket.accept();
    			// ObjectInputStream 会发生阻塞!!
    			in = new ObjectInputStream(socket.getInputStream());
    			Call call = (Call)in.readObject();
    			System.out.println("-- get call [" + call.getClassName()
    					           + ":" + call.getMethodName() + "]");
    			call = invoke(call);
    			out = new ObjectOutputStream(socket.getOutputStream());
    			out.writeObject(call);
    			out.flush();
			} catch(Exception e){
				e.printStackTrace();
			} finally{
				try{
					if(in != null){
						in.close();
					}
					if(out != null){
						out.close();
					}
				} catch(Exception e){
				}
			}
		}
	}
	/**
	 * 调用 call 所指定的的方法
	 * @param call
	 * @return
	 */
	public Call invoke(Call call){
		Object obj = map_objs.get(call.getClassName());
		if(obj == null){
			try {
	            obj = Class.forName(call.getClassName()).newInstance();
	            map_objs.put(call.getClassName(), obj);
            } catch (Exception e) {
	            e.printStackTrace();
            }
		}
		try {
	        Method method = obj.getClass().getMethod(
	        			    call.getMethodName(),
	        			    call.getParamTypes());
	        Object result = method.invoke(obj, call.getParams());
	        call.setResult(result);
        } catch (Exception e) {
	        e.printStackTrace();
        }
		return call;
	}
	
	public static void main(String[] args)throws Exception{
		SimpleServer server = new SimpleServer();
		server.service();
	}
}

// remote.service.HelloServiceImpl.java
package remote.service;

import java.util.Date;

import share.service.HelloService;

/**
 *@date 2010-3-13 下午04:30:44
 *@author dycc
 *@file remote.service.HelloServiceImpl.java
 */
public class HelloServiceImpl implements HelloService{
	public String echo(String msg) {
	    return "echo:" + msg;
	}
	public Date getTime() {
	    return new Date();
	}
}