Socket实例之客户端向服务端数据库上传文件UI版

运行结果：

首先实现分析：

1用户注册
客户单选择‘用户注册’，提示要输入用户名，密码，确认密码，校验成功后将用户
信息保存到数据库，并提示数据库注册成功，请登录
2用户登录
客户端选择‘登录以后’后，提示输入用户名和密码，验证成功则提示上传文件
，验证失败则给出提示信息，并可以重新登录
3文件上传
客户端输入上传文件的路径，并读取文件数据，通过输出流发送到服务端，服务端接受
后将上传文件保持在数据库

所有类如图：

cn.edu.xynu.entity包里面有两个实体类

分别是数据库中的用户内容和文件内容。

数据库中的两张表的设计如下图

User实体类。和数据库的user表内容一致

 

package cn.edu.xynu.entity;

import java.io.Serializable;

public class User implements Serializable{
  /**
   * 用户的实体类
   */
  private static final long serialVersionUID = 4015036439904829095L;
  private String username;
  private String password;

  public User() {
    super();
    // TODO Auto-generated constructor stub
  }

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

}

File实体类和数据库的File表内容一致

package cn.edu.xynu.entity;

import java.io.Serializable;

public class File implements Serializable{

  /**
   * 文件的实体类
   */
  private static final long serialVersionUID = 1L;
  private String fname;
  private String username;
  private byte[] fcontent;
  public File() {
    super();
    // TODO Auto-generated constructor stub
  }

  public File(String fname, String username, byte[] fcontent) {
    super();
    this.fname = fname;
    this.username = username;
    this.fcontent = fcontent;
  }

  public String getUsername() {
    return username;
  }

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

  public String getFname() {
    return fname;
  }
  public void setFname(String fname) {
    this.fname = fname;
  }
  public byte[] getFcontent() {
    return fcontent;
  }
  public void setFcontent(byte[] fcontent) {
    this.fcontent = fcontent;
  }
  
}

cn.edu.xynu.service包里主要是对业务的实现

 

FileService 类实现客户端文件向服务器数据库的上传

 

package cn.edu.xynu.service;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import cn.edu.xynu.entity.File;
import cn.edu.xynu.util.DBHelper;

/**
 * @author scx
 * 文件服务类
 */
public class FileService {
  //上传文件
  public boolean uploadFile(File file) {
    Connection conn = null;
    PreparedStatement ps = null;
    conn = DBHelper.getConnection();
    String sql = "insert into file (username,filename,filecontent) values(?,?,?)";
    try {
      ps = conn.prepareStatement(sql);
      ps.setString(1, file.getUsername().trim());
      ps.setString(2, file.getFname().trim());
      ps.setBytes(3, file.getFcontent());
      int n=ps.executeUpdate();
      if(n>0){
        return true;
      }
    } catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally{
      try {
        if(conn!=null)
          conn.close();
        if(ps!=null)
          ps.close();
      } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
    return false;
  }
}

UserService类主要实现用户的登录和注册

package cn.edu.xynu.service;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import cn.edu.xynu.entity.User;
import cn.edu.xynu.util.DBHelper;

/**
 * @author scx
 * 用户服务类
 */
public class UserService {
  private Connection conn = null;
  private PreparedStatement ps = null;
  //检测账户在数据库是否存在
  public boolean checkUser(User user) {
    String username = user.getUsername();
    String password = user.getPassword();
    try {
      conn = DBHelper.getConnection();
      String sql = "select * from user where username =? and password=?";
      ps = conn.prepareStatement(sql);
      ps.setString(1, username);
      ps.setString(2, password);
      ResultSet rs = ps.executeQuery();
      rs.last();
      int n = rs.getRow();
      if (n > 0) {
        return true;
      }
    } catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } finally {
      try {
        if (ps != null)
          ps.close();
      } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
    return false;
  }
  //在数据库中添加注册的用户
  public boolean addUser(User user) {
    String username = user.getUsername();
    String password = user.getPassword();
    try {
      conn = DBHelper.getConnection();
      String sql = "insert into user (username,password) values(?,?)";
      ps = conn.prepareStatement(sql);
      ps.setString(1, username);
      ps.setString(2, password);
      int x = ps.executeUpdate();
      if (x > 0) {
        return true;
      }
    } catch (SQLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } finally {
      try {
        if (ps != null)
          ps.close();
      } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
    return false;
  }
}

然后cn.edu.xynu.socket包里面主要是socket编程的类

 

Client类实现与服务端的通信

 

package cn.edu.xynu.socket;

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

import cn.edu.xynu.util.CommandTranser;

/**
 * @author scx
 * 客户端
 */
public class Client {
  public static Socket socket=null;
  public static int port=8888;
  public static String address="127.0.0.1";
  //获得服务器的数据
  public static CommandTranser getData() {
    // TODO Auto-generated method stub
    ObjectInputStream ois=null;
    CommandTranser res=null;
    try {
      ois=new ObjectInputStream(Client.socket.getInputStream());
      res=(CommandTranser) ois.readObject();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (ClassNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally{
      if(ois!=null){
        try {
          ois.close();
        } catch (IOException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
      }
    }
    return res;
  }
  //向服务器发送数据
  public static void sendData(CommandTranser cmd) {
    // TODO Auto-generated method stub
    ObjectOutputStream oos=null;
    try {
      oos=new ObjectOutputStream(Client.socket.getOutputStream());
      oos.writeObject(cmd);
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
}

Service类服务端主要实现监听客户端的连接

package cn.edu.xynu.socket;

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import javax.swing.JOptionPane;



/**
 * @author scx
 * 服务端
 */
public class Service {
  public Service(){
    try {
      ServerSocket ss=new ServerSocket(8888);
      Socket socket=null;
      JOptionPane.showMessageDialog(null, "服务器已启动!请连接...");
      //循环监听客户端的连接
      while(true){
        socket=ss.accept();
        //为每个客户开启一个线程
        ServiceThread serviceThread=new ServiceThread(socket);
        Thread thread=new Thread(serviceThread);
        thread.start();
      }
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }

  
}

服务器线程类,ServiceThread,多线程实现多用户的连接

package cn.edu.xynu.socket;

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

import cn.edu.xynu.entity.File;
import cn.edu.xynu.entity.User;
import cn.edu.xynu.service.FileService;
import cn.edu.xynu.service.UserService;
import cn.edu.xynu.util.CommandTranser;

/**
 * @author scx
 * 服务器线程
 */
public class ServiceThread implements Runnable {
  private Socket socket;

  public ServiceThread(Socket socket) {
    this.socket = socket;
  }

  @Override
  public void run() {
    // TODO Auto-generated method stub
    ObjectInputStream ois = null;
    ObjectOutputStream oos = null;
    try {
      ois = new ObjectInputStream(socket.getInputStream());
      oos = new ObjectOutputStream(socket.getOutputStream());
      CommandTranser cmd=(CommandTranser) ois.readObject();
      //处理客户端发送来的数据
      cmd=execute(cmd);
      oos.writeObject(cmd);
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (ClassNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }finally{
      try {
        if(ois!=null)
          ois.close();
        if(oos!=null){
          oos.close();
        }
      } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }

  }
  //处理客户端发送来的数据
  private CommandTranser execute(CommandTranser cmd) {
    // TODO Auto-generated method stub
    //客户端登录操作
    if("login".equals(cmd.getCmd())){
      UserService userService=new UserService();
      User user=(User) cmd.getData();
      cmd.setFlag(userService.checkUser(user));
      if(cmd.isFlag()){
        cmd.setResult("登录成功！！");
      }else{
        cmd.setResult("oh my god !!登录失败了。。");
      }
    }
    //客户端注册用户操作
    if("register".equals(cmd.getCmd())){
      UserService userService=new UserService();
      User user=(User) cmd.getData();
      cmd.setFlag(userService.addUser(user));
      if(cmd.isFlag()){
        cmd.setResult("恭喜你。注册成功，请登录!");
      }else{
        cmd.setResult("oh my god !!注册失败了..");
      }
    }
    //客户端上传文件操作
    if("uploadFile".equals(cmd.getCmd())){
      FileService fileService=new FileService();
      File file=(File) cmd.getData();
      cmd.setFlag(fileService.uploadFile(file));
      if(cmd.isFlag()){
        cmd.setResult("恭喜你，上传成功!");
      }else{
        cmd.setResult("很遗憾，上传失败！");
      }
    }
    return cmd;
  }

}

cn.edu.xynu.ui 都是各种界面设计

 

客户端登录界面loginUI类

 

package cn.edu.xynu.ui;

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

import cn.edu.xynu.entity.User;
import cn.edu.xynu.socket.Client;
import cn.edu.xynu.util.CommandTranser;

/**
 * @author scx
 * 客户端登录界面
 */
public class LoginUI extends JFrame implements ActionListener {
  private static final long serialVersionUID = -2686222552198867018L;
  private Box box1, box2, box3, baseBox;
  private JLabel username, password;
  private JTextField username_txt;
  private JPasswordField password_txt;
  private JButton login_btn, register_btn;
  public LoginUI() {
    setLayout(new FlowLayout());
    init();
    setTitle("客户端");
    setSize(200, 150);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setResizable(false);
    setVisible(true);
  }

  private void init() {
    username = new JLabel("账户");
    password = new JLabel("密码");
    username_txt = new JTextField(10);
    password_txt = new JPasswordField(10);
    login_btn = new JButton("登录");
    register_btn = new JButton("注册");
    box1 = Box.createHorizontalBox();
    box2 = Box.createHorizontalBox();
    box3 = Box.createHorizontalBox();
    box1.add(username);
    box1.add(Box.createHorizontalStrut(8));
    box1.add(username_txt);
    box2.add(password);
    box2.add(Box.createHorizontalStrut(8));
    box2.add(password_txt);
    box3.add(login_btn);
    box3.add(Box.createHorizontalStrut(8));
    box3.add(register_btn);
    baseBox = Box.createVerticalBox();
    baseBox.add(box1);
    baseBox.add(Box.createVerticalStrut(5));
    baseBox.add(box2);
    baseBox.add(Box.createVerticalStrut(5));
    baseBox.add(box3);
    baseBox.add(Box.createVerticalStrut(5));
    add(baseBox);
    login_btn.addActionListener(this);
    register_btn.addActionListener(this);
  }

  @Override
  public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    //如果点击了登录按钮  判断账户在服务器是否存在
    if(e.getSource()==login_btn){
      User user=new User();
      user.setUsername(username_txt.getText().trim());
      user.setPassword(new String(password_txt.getPassword()).trim());
      CommandTranser cmd =new CommandTranser();
      cmd.setData(user);
      cmd.setCmd("login");
      try {
        Client.socket=new Socket(Client.address, Client.port);
        //向服务器发送数据
        Client.sendData(cmd);
        //获得服务器发送的数据
        cmd =Client.getData();
        JOptionPane.showMessageDialog(null, cmd.getResult());
        //如果登录成功  关闭此窗口 开启上传窗口
        if(cmd.isFlag()){
          this.dispose();
          new UploadUI(user.getUsername());
        }
      } catch (UnknownHostException e1) {
        // TODO Auto-generated catch block
        JOptionPane.showMessageDialog(null, "服务端未开启！");
      } catch (IOException e1) {
        // TODO Auto-generated catch block
        JOptionPane.showMessageDialog(null, "服务端未开启！");
      }
    }
    //如果点击了注册按钮  打开注册界面
    if(e.getSource()==register_btn){
      new RegisterUI();
    }
  }

  
}

客户端注册界面RegisterUI类

package cn.edu.xynu.ui;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

import cn.edu.xynu.entity.User;
import cn.edu.xynu.socket.Client;
import cn.edu.xynu.util.CommandTranser;

/**
 * @author scx
 * 客户端注册界面
 */
public class RegisterUI extends JFrame implements ActionListener{
  private static final long serialVersionUID = -717590965372186957L;
  private Box box1, box2, baseBox;
  private JLabel username, password,password2;
  private JTextField username_txt;
  private JPasswordField password_txt,password_txt2;
  private JButton cancel_btn, register_btn;
  public RegisterUI(){
    setLayout(new FlowLayout());
    init();
    setTitle("注册");
    setSize(250, 200);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(JFrame.HIDE_ON_CLOSE);
    setVisible(true);
    setResizable(false);
  }
  private void init() {
    // TODO Auto-generated method stub
    username = new JLabel("账户");
    password = new JLabel("密码");
    password2=new JLabel("再次输入密码");
    username_txt = new JTextField(10);
    password_txt = new JPasswordField(10);
    password_txt2=new JPasswordField(10);
    cancel_btn = new JButton("取消");
    register_btn = new JButton("注册");
    box1=Box.createVerticalBox();
    box2=Box.createVerticalBox();
    box1.add(username);
    box1.add(Box.createVerticalStrut(10));
    box1.add(password);
    box1.add(Box.createVerticalStrut(10));
    box1.add(password2);
    box1.add(Box.createVerticalStrut(10));
    
    box2.add(username_txt);
    box2.add(Box.createVerticalStrut(10));
    box2.add(password_txt);
    box2.add(Box.createVerticalStrut(10));
    box2.add(password_txt2);
    box2.add(Box.createVerticalStrut(10));
    baseBox=Box.createHorizontalBox();
    baseBox.add(box1);
    baseBox.add(Box.createHorizontalStrut(5));
    baseBox.add(box2);
    add(baseBox);
    add(register_btn);
    add(cancel_btn);
    cancel_btn.addActionListener(this);
    register_btn.addActionListener(this);
  }
  @Override
  public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    if(e.getSource()==register_btn){
      String username=username_txt.getText().trim();
      String password1=new String(password_txt.getPassword()).trim();
      String password2=new String(password_txt2.getPassword()).trim();
      if(username==null||"".equals(username)){
        JOptionPane.showMessageDialog(null, "请输入用户名！！");
        return ;
      }
      if(password1==null||"".equals(password1)){
        JOptionPane.showMessageDialog(null, "请输入密码！！");
        return ;
      }
      if(!(password1.equals(password2))){
        JOptionPane.showMessageDialog(null, "两次输入的密码不一致！！");
        return ;
      }
      //向服务器发送注册信息
      User user=new User(username, password1);
      CommandTranser cmd=new CommandTranser();
      cmd.setCmd("register");
      cmd.setData(user);
      try {
        Client.socket=new Socket(Client.address, Client.port);
        //向服务器发送数据
        Client.sendData(cmd);
        //获得服务器发送的数据
        cmd =Client.getData();
        JOptionPane.showMessageDialog(null, cmd.getResult());
      } catch (UnknownHostException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
      } catch (IOException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
      }
    }
    //初始化文本框
    if(e.getSource()==cancel_btn){
      username_txt.setText(null);
      password_txt.setText(null);
      password_txt2.setText(null);
    }
  }
}

开启客户端界面

package cn.edu.xynu.ui;

/**
 * @author scx
 * 开启客户端
 */
public class StartClient {
  public static void main(String[] args) {
    new LoginUI();
  }
}

开启服务端界面，需要注意一点、

在线程中开启服务器 避免使用main线程 服务器一直开启
 main线程一直阻塞 无法对其它事物进行处理

package cn.edu.xynu.ui;

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;

import cn.edu.xynu.socket.Service;
/**
 * 开启服务端界面
 */
public class StartServer extends JFrame implements ActionListener{
  private static final long serialVersionUID = 3254784569816648178L;
  private JButton startServer_btn;
  private JButton endServer_btn;
  private Service startService;
  public StartServer(){
    setLayout(new FlowLayout());
    startServer_btn=new JButton("开启服务");
    endServer_btn=new JButton("关闭服务");
    add(startServer_btn);
    add(endServer_btn);
    setTitle("服务端");
    setSize(300, 200);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    startServer_btn.addActionListener(this);
    endServer_btn.addActionListener(this);
  }
  public static void main(String[] args) {
    // TODO Auto-generated method stub
    new StartServer();
  }
  @Override
  public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    if(e.getSource()==startServer_btn){
      if(startService==null){
        /*
         * 在线程中开启服务器  避免使用main线程 服务器一直开启 
         * main线程一直阻塞  无法对其它事物进行处理
         */
        new startServerThread().start();
      }
    }
    //退出服务器
    if(e.getSource()==endServer_btn){
      startService=null;
      System.exit(0);
    }
  }
  private class startServerThread extends Thread{
    @Override
    public void run() {
      // TODO Auto-generated method stub
      startService=new Service();
    }
  }
}

 

文件上传界面，主要控件有

 

一个选择文件按钮  一个确认上传按钮，一个显示文件路径的文本框

 

package cn.edu.xynu.ui;

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.net.Socket;
import java.net.UnknownHostException;

import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JTextField;

import cn.edu.xynu.entity.File;
import cn.edu.xynu.socket.Client;
import cn.edu.xynu.util.CommandTranser;

/**
 * @author scx
 * 上传文件界面
 */
public class UploadUI extends JFrame implements ActionListener {
  private static final long serialVersionUID = -8830003248247613172L;
  private JFileChooser fileChooser;//文件选择对话框
  private JButton upload_btn, choose_btn;//上传按钮 和选择按钮
  private JTextField path_txt;//文件的绝对路径
  private String username;//成功登录的用户名

  public UploadUI(String username) {
    this.username = username;
    init();
    setTitle("上传文件");
    setSize(250, 200);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setVisible(true);
    setResizable(false);
  }

  private void init() {
    // TODO Auto-generated method stub
    setLayout(new FlowLayout());
    choose_btn = new JButton("选择");
    upload_btn = new JButton("上传");
    fileChooser = new JFileChooser();
    path_txt = new JTextField(20);
    add(path_txt);
    add(choose_btn);
    add(upload_btn);
    choose_btn.addActionListener(this);
    upload_btn.addActionListener(this);
  }

  @Override
  public void actionPerformed(ActionEvent e) {
    // TODO Auto-generated method stub
    // 如果点击了选择文件
    if (e.getSource() == choose_btn) {
      //打开选择文件对话框
      int state = fileChooser.showSaveDialog(null);
      if (state == 0) {
        String pathChoose = fileChooser.getSelectedFile().getPath();
        path_txt.setText(pathChoose);
      }
    }
    // 如果点击了上传按钮
    if (e.getSource() == upload_btn) {
      if(path_txt.getText().trim()==null||"".equals(path_txt.getText().trim())){
        JOptionPane.showMessageDialog(null, "请先选择文件再上传！！");
        return ;
      }
      uploadFile();
    }
  }
  //上传文件
  private void uploadFile() {
    // TODO Auto-generated method stub
    File file = null;
    FileInputStream fis = null;
    BufferedInputStream bis = null;
    String path = path_txt.getText().trim();
    String fname = path.substring(path.lastIndexOf("\\") + 1);
    try {
      fis = new FileInputStream(path);
      // fis.available返回文件的总大小
      byte[] fcontent = new byte[fis.available()];
      bis = new BufferedInputStream(fis);
      //读取文件内容
      bis.read(fcontent);
      //实例化file对象
      file = new File(fname, username, fcontent);

    } catch (FileNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } finally {
      if (bis != null)
        try {
          bis.close();
        } catch (IOException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }
    }
    //向服务器发送文件
    CommandTranser cmd = new CommandTranser();
    cmd.setData(file);
    cmd.setCmd("uploadFile");
    try {
      Client.socket = new Socket(Client.address,
          Client.port);
      //向服务器发送数据
      Client.sendData(cmd);
      //获得服务器反馈信息
      cmd = Client.getData();
      JOptionPane.showMessageDialog(null, cmd.getResult());
    } catch (UnknownHostException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }

  }
}

cn.edu.xynu.util包里面就是工具类 

CommandTranser类 主要负责客户端向服务端发送数据以及服务器向客户端返回的数据

 

package cn.edu.xynu.util;

import java.io.Serializable;

/**
 * @author scx
 * 用户指令类
 */
public class CommandTranser implements Serializable{
  private static final long serialVersionUID = 1L;
  private String cmd;//操作指令
  private Object data;//发送的数据
  private boolean flag;//操作是否成功
  private String result;//返回的结果
  public String getCmd() {
    return cmd;
  }
  public void setCmd(String cmd) {
    this.cmd = cmd;
  }
  public Object getData() {
    return data;
  }
  public void setData(Object data) {
    this.data = data;
  }
  public boolean isFlag() {
    return flag;
  }
  public void setFlag(boolean flag) {
    this.flag = flag;
  }
  public String getResult() {
    return result;
  }
  public void setResult(String result) {
    this.result = result;
  }
  
}

数据库工具类

package cn.edu.xynu.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

/**
 * @author scx
 * 数据库
 */
public class DBHelper {
  private static final String driver="com.mysql.jdbc.Driver";
  private static final String url="jdbc:mysql://localhost:3306/susu?useUnicode=true&charcterEncoding=UTF-8";
  private static final String username="root";
  private static final String password="";
  private static  Connection con=null;
  //静态块代码负责加载驱动
  static
  {
    try {
      Class.forName(driver);
    } catch (ClassNotFoundException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
  }
  public static Connection getConnection(){

    if(con==null){
      try {
        con=DriverManager.getConnection(url, username, password);
      } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
    return con;
  }
}