（转载）Java Socket实战之三：传输对象

前面两篇文章介绍了怎样建立Java Socket通信，这一篇说一下怎样使用Java Socket来传输对象。

首先需要一个普通的对象类，由于需要序列化这个对象以便在网络上传输，所以实现java.io.Serializable接口就是必不可少的了，如下：

package com.googlecode.garbagecan.test.socket.sample3;

public class User implements java.io.Serializable {
    private static final long serialVersionUID = 1L;
    private String name;
    private String password;

    public User() {

    }

    public User(String name, String password) {
        this.name = name;
        this.password = password;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

对于Server端的代码，代码中分别使用了ObjectInputStream和ObjectOutputStream来接收和发送socket中的InputStream和OutputStream，然后转换成Java对象，如下：

package com.googlecode.garbagecan.test.socket.sample3;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;

public class MyServer {

    private final static Logger logger = Logger.getLogger(MyServer.class.getName());

    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(10000);

        while (true) {
            Socket socket = server.accept();
            invoke(socket);
        }
    }

    private static void invoke(final Socket socket) throws IOException {
        new Thread(new Runnable() {
            public void run() {
                ObjectInputStream is = null;
                ObjectOutputStream os = null;
                try {
                    is = new ObjectInputStream(new BufferedInputStream(socket.getInputStream()));
                    os = new ObjectOutputStream(socket.getOutputStream());

                    Object obj = is.readObject();
                    User user = (User)obj;
                    System.out.println("user: " + user.getName() + "/" + user.getPassword());

                    user.setName(user.getName() + "_new");
                    user.setPassword(user.getPassword() + "_new");

                    os.writeObject(user);
                    os.flush();
                } catch (IOException ex) {
                    logger.log(Level.SEVERE, null, ex);
                } catch(ClassNotFoundException ex) {
                    logger.log(Level.SEVERE, null, ex);
                } finally {
                    try {
                        is.close();
                    } catch(Exception ex) {}
                    try {
                        os.close();
                    } catch(Exception ex) {}
                    try {
                        socket.close();
                    } catch(Exception ex) {}
                }
            }
        }).start();
    }
}

Client也和Server端类似，同样使用ObjectOutputStream和ObjectInputStream来处理，如下：

package com.googlecode.garbagecan.test.socket.sample3;

import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;

public class MyClient {

    private final static Logger logger = Logger.getLogger(MyClient.class.getName());

    public static void main(String[] args) throws Exception {
        for (int i = 0; i < 100; i++) {
            Socket socket = null;
            ObjectOutputStream os = null;
            ObjectInputStream is = null;

            try {
                socket = new Socket("localhost", 10000);

                os = new ObjectOutputStream(socket.getOutputStream());
                User user = new User("user_" + i, "password_" + i);
                os.writeObject(user);
                os.flush();

                is = new ObjectInputStream(new BufferedInputStream(socket.getInputStream()));
                Object obj = is.readObject();
                if (obj != null) {
                    user = (User)obj;
                    System.out.println("user: " + user.getName() + "/" + user.getPassword());
                }
            } catch(IOException ex) {
                logger.log(Level.SEVERE, null, ex);
            } finally {
                try {
                    is.close();
                } catch(Exception ex) {}
                try {
                    os.close();
                } catch(Exception ex) {}
                try {
                    socket.close();
                } catch(Exception ex) {}
            }
        }
    }
}

最后测试上面的代码，首先运行Server类，然后运行Client类，就可以分别在Server端和Client端控制台看到接收到的User对象实例了。