java怎么通过TCP协议传输javabean对象

package tcp.entity;

import java.io.Serializable;

public class User implements Serializable {

  /**
   * 
   */
  private static final long serialVersionUID = 1L;

  private String username;
  private String password;

  public String getUsername() {
    return username;
  }

  public void setUsername(String username) {
    this.username = username;
  }

  public String getPassword() {
    return password;
  }

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

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

  public User() {
    super();
  }
}

package tcp.client;

import java.io.DataInputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.util.Scanner;

import tcp.entity.User;

public class MyClient {
    public static void main(String[] args) {
        System.out.println("-----------客户端启动...------------");
        Socket client = null;
        try {
            Scanner sc = new Scanner(System.in);
            while (true) {
                User user = null;
                String str = null;

                System.out.println("请输入用户名：");
                str = sc.nextLine();
                if (!"".equals(str)) {
                    user = new User();
                    user.setUsername(str);
                } else {
                    continue;
                }
                System.out.println("请输入用户密码：");
                str = sc.nextLine();
                user.setPassword(str);

                client = new Socket("localhost", 8848); // 一新建对象就会向服务器发起TCP连接
                /**
                 * 注意：如果使用BufferedOutputStream提高效率，那么需要在write输出完成后调用flush()将缓存的数据真正输出到网络中去，否则将报找不到EOF结尾的异常。
                 */
                ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(client.getOutputStream()));
                DataInputStream dis = new DataInputStream(new BufferedInputStream(client.getInputStream()));
                oos.writeObject(user); // 发送到服务器
                oos.flush();
                System.out.println(dis.readUTF());// 从服务器接受回显

                System.out.print("是否退出？");
                str = sc.nextLine();
                if ("y".equalsIgnoreCase(str)) {
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (client != null)
                    client.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

package tcp.server;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class MyServer {
  public static void main(String[] args) {
    System.out.println("=================服务器启动...===================");
    ServerSocket server = null;
    try {
      server = new ServerSocket(8848);
      while (true) {
        // 侦听端口等待客户端连接
        Socket client = server.accept(); // 阻塞。通过说明新产生了一个client。
        new Thread(new LoginHandler(client)).start(); // 当LoginHandler()处理完后，当前client就被gc了。
      }
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      try {
        if (server != null)
          server.close();
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }
}

package tcp.server;

import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.OutputStream;
import java.net.Socket;

import tcp.entity.User;

public class LoginHandler implements Runnable {

    private Socket client;

    @Override
    public void run() {
        InputStream is = null;
        OutputStream os = null;
        try {
            is = client.getInputStream();
            os = client.getOutputStream();
            /**
             * 注意：如果使用BufferedOutputStream提高效率，那么需要在write输出完成后调用flush()将缓存的数据真正输出到网络中去，否则将报找不到EOF结尾的异常。
             */
            ObjectInputStream ois = new ObjectInputStream(new BufferedInputStream(is));
            DataOutputStream dos = new DataOutputStream(new BufferedOutputStream(os));

            // 反序列化
            User user = (User) ois.readObject();
            // 登陆判断
            if (user != null) {
                System.out.println("用户 ：" + user.getUsername() + "[" + client.getInetAddress().getHostAddress() + ":"
                        + client.getPort() + "]" + "密码：" + user.getPassword());
                if ("cerana".equals(user.getUsername()) && "bulabula".equals(user.getPassword())) {
                    dos.writeUTF("登陆成功");
                    dos.flush();
                } else {
                    dos.writeUTF("登陆失败");
                    dos.flush();
                }
            } else {
                System.out.println("反序列化失败");
            }
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        } finally {
            try {
                if (os != null)
                    os.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

            try {
                if (is != null)
                    is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public LoginHandler(Socket client) {
        super();
        this.client = client;
    }
}