Java操作mysql（jdbc）实现动态的增删查改

首先明确我们的目标：创建一个员工管理系统的用户登录界面，要求有：实现用户的注册，登录，修改密码，注销等操作。

1. 根据分析我们首先得写一个登录窗口：
   

分析步骤如下
- 首先实现一个窗口，调整位置大小，设置为可见
- 然后添加组件，图片等（合理运用好布局，流式，网格）
- 最后对按键组件添加监听事件

package day01;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class RegistFrame extends JFrame {
    JTextField txtUserName;
    JPasswordField txtPassword;
    String id;
    String pass;
    //构造器
    public RegistFrame(){
        init();
    }
    public void init(){
        //初始化窗口
        this.setTitle("登录窗口");
        this.setContentPane(createContentPane());
        this.setLocation(800, 400);
        this.setSize(400, 300);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        //this.pack();
        this.setVisible(true);
    }
    public JPanel createContentPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new BorderLayout());
        JLabel label = new JLabel("登录界面",JLabel.CENTER);
        panel.add(BorderLayout.NORTH,label);
        panel.add(BorderLayout.CENTER,createCenterPane());

        panel.add(BorderLayout.SOUTH,createBottomPane());
        return panel;
    }
    public JPanel createCenterPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new BorderLayout());
        Icon image = new ImageIcon("src/day01/sh.jpg");
        JLabel label = new JLabel(image);
        panel.add(BorderLayout.CENTER,label);
        panel.add(BorderLayout.SOUTH,createIdPwdPane());
        return panel;
    }
    public JPanel createIdPwdPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(2,3,5,5));
        panel.add(new JLabel("用  户  名：",JLabel.CENTER));
        txtUserName = new JTextField(15);
        panel.add(txtUserName);
        JButton b3 = new JButton("修改密码");
        panel.add(b3);
        panel.add(new JLabel("密        码：",JLabel.CENTER));
        txtPassword = new JPasswordField(15);
        panel.add(txtPassword);
        JButton b4 = new JButton("注销");
        panel.add(b4);
        b3.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                new Siugaimima();
            }
        });
        b4.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                new Zhuxiao();
            }
        });
        return panel;
    }
    public JPanel createBottomPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new FlowLayout());
        JButton b1 = new JButton("登录");
        JButton b2 = new JButton("注册");
        panel.add(b1);
        panel.add(b2);
        b1.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                id = txtUserName.getText();
                pass = txtPassword.getText();
                System.out.println(id +" "+pass);
                Service p = new Service();
                if(!p.login(id, pass)){
                    JOptionPane.showMessageDialog(RegistFrame.this,"账号或密码错误");
                    clearText();
                }else{
                    setVisible(false);
                    new Frame();
                    dispose();
                }
            }
        });
        b2.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                id = txtUserName.getText();
                pass = txtPassword.getText();
                Service p = new Service();
                if(p.regist(id, pass)){
                    JOptionPane.showMessageDialog(RegistFrame.this,"注册成功");         
                }else{
                    JOptionPane.showMessageDialog(RegistFrame.this,"注册失败");
                }
            }
        }); 
        return panel;
    }
    protected void clearText() {
        txtPassword.setText("");
        }       
}

1. 具体实现修改密码和注销用户的按钮监听

思路如下：

• 点击其按钮时弹出修改密码和注销界面（注意错误处理）
• 其中首先我们还需要连接数据库
• 最后实现修改密码（对数据库进行改操作）和注销界面（对数据库进行删操作）
  
  

//连接数据库
package day01;

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

public class LianjieSql {
    public Connection lianjie(){
        String url = "jdbc:mysql://127.0.0.1:3307/web";
        String user = "kai";
        String password = "kk";
        //反射
        try {
            //注册驱动
            Class.forName("com.mysql.jdbc.Driver");
            //获取连接
            Connection conn;
            try {
                conn = DriverManager.getConnection(url,user,password);
                return conn;
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
            }
        return null;
    }
    public  static void close( Statement stat, Connection conn) throws SQLException{
        if(stat!=null){
            ((Connection) stat).close();
        }if(conn!=null){
            conn.close();
        }
    } 
}

//对修改密码进行监听事件的实现
package day01;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class Siugaimima extends JFrame {
    JTextField txtUserName;
    JPasswordField txtPassword,txtPassword1;
    String id,pass,oldpass;
    //构造器
    public  Siugaimima() {
        init();
    }
    public void init(){
        //初始化窗口
        this.setTitle("修改密码");
        this.setContentPane(createContentPane());
        this.setLocation(800, 400);
        //this.setSize(400, 300);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }
    public JPanel createContentPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new BorderLayout());
        JLabel label = new JLabel("修改密码",JLabel.CENTER);
        panel.add(BorderLayout.NORTH,label);
        panel.add(BorderLayout.CENTER,createIdPwdPane());

        panel.add(BorderLayout.SOUTH,createBottomPane());
        return panel;
    }
    public JPanel createIdPwdPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(3,2,5,5));
        panel.add(new JLabel("用  户  名："));
        txtUserName = new JTextField(15);
        panel.add(txtUserName);
        panel.add(new JLabel("旧  密   码："));
        txtPassword = new JPasswordField(15);
        panel.add(txtPassword);
        panel.add(new JLabel("新   密   码："));
        txtPassword1 = new JPasswordField(15);
        panel.add(txtPassword1);
        return panel;
    }
    public JPanel createBottomPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new FlowLayout());
        JButton b1 = new JButton("修改");
        JButton b2 = new JButton("取消");
        panel.add(b1);
        panel.add(b2);
        b1.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                id = txtUserName.getText();
                oldpass = txtPassword.getText();
                pass = txtPassword1.getText();

                System.out.println(id +" "+pass);
                Service p = new Service();
                if(!p.updatepwd(id,oldpass,pass)){
                    JOptionPane.showMessageDialog(Siugaimima.this,"用户名或密码错误");
                    clearText();
                }else{
                    JOptionPane.showMessageDialog(Siugaimima.this,"修改成功");
                    setVisible(false);
                    dispose();
                }
            }
        });
        b2.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                setVisible(false);
                dispose();
            }
        }); 
        return panel;
    }
    protected void clearText() {
        // TODO Auto-generated method stub
        txtPassword.setText("");
        txtPassword1.setText("");
        }       
}

//对注销按键进行事件处理
package day01;

import java.awt.BorderLayout;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class Zhuxiao extends JFrame {
    JTextField txtUserName;
    JPasswordField txtPassword;
    String id;
    String pass;
    //构造器
    public Zhuxiao(){
        init();
    }
    public void init(){
        //初始化窗口
        this.setTitle("注销用户");
        this.setContentPane(createContentPane());
        this.setLocation(800, 400);
        //this.setSize(400, 300);
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }
    public JPanel createContentPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new BorderLayout());
        JLabel label = new JLabel("注销界面",JLabel.CENTER);
        panel.add(BorderLayout.NORTH,label);
        panel.add(BorderLayout.CENTER,createIdPwdPane());

        panel.add(BorderLayout.SOUTH,createBottomPane());
        return panel;
    }
    public JPanel createIdPwdPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new GridLayout(2,2,5,5));
        panel.add(new JLabel("用  户  名："));
        txtUserName = new JTextField(15);
        panel.add(txtUserName);
        panel.add(new JLabel("密        码："));
        txtPassword = new JPasswordField(15);
        panel.add(txtPassword);
        return panel;
    }
    public JPanel createBottomPane(){
        JPanel panel = new JPanel();
        panel.setLayout(new FlowLayout());
        JButton b3 = new JButton("注销");
        JButton b4 = new JButton("取消");
        panel.add(b3);
        panel.add(b4);
        b3.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                id = txtUserName.getText();
                pass = txtPassword.getText();
                System.out.println(id +" "+pass);
                Service p = new Service();
                if(!p.delete(id, pass)){
                    JOptionPane.showMessageDialog(Zhuxiao.this,"账号或密码错误");
                    clearText();
                }else{
                    JOptionPane.showMessageDialog(Zhuxiao.this,"注销成功");
                    setVisible(false);
                    dispose();
                }
            }
        });
        b4.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent arg0) {
                // TODO Auto-generated method stub
                setVisible(false);
                dispose();
            }
        });
        return panel;
    }
    protected void clearText() {
        txtPassword.setText("");
        }       
}

1. 我们大体的框架搭建完成，接下来我们得实现具体的数据库操作

具体步骤：

• 从点击按钮事件中获取到文本框信息
• 将信息传入实现函数中
• 完成具体的数据库操作

//业务层，对按键监听的统一层
package day01;

import java.sql.ResultSet;
import java.sql.SQLException;

public class Service {
    //注册
    public boolean regist(String id,String pwd){
        Dao db = new Dao();
        int n = db.insert(id, pwd);
        if(n > 0){
            return true;
        }
        return false;
    }
    //登录
    public boolean login(String id,String pwd){
        Dao db = new Dao();
        ResultSet p = db.select(id, pwd);
        try {
            if(p.next()){
                return true;
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            return false;
            //e.printStackTrace();
        }
        return false;
    }
    //修改密码
    public boolean  updatepwd(String id,String oldpass,String pwd){
        Dao db = new Dao();
        int n = db.updete(id,oldpass,pwd);
        if(n > 0){
            return true;
        }
        return false;
    }
    //注销用户
    public boolean delete(String id,String pwd){
        Dao db = new Dao();
        int n = db.delete(id,pwd);
        if(n > 0){
            return true;
        }
        return false;
    }
}

//数据层——对业务层的具体实现
package day01;

import java.beans.Statement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;


//数据层——对数据库的操作
public class Dao {
    LianjieSql db = new LianjieSql();
    Connection conn = db.lianjie();
    java.sql.Statement stat = null;
    public int insert(String id,String pwd){
        try {
            String sql="insert into user values("+id+","+pwd+")"; 
            stat = conn.createStatement();
            int result = stat.executeUpdate(sql);
            return result;
        } catch (SQLException e1) {
            // TODO Auto-generated catch block
            System.out.println("注册失败！");
            //e1.printStackTrace();
        }  
        return 0;
    }

    public int updete(String id,String oldpass,String pwd){
        try {
            String sql="update user set pass="+pwd+" where id="+id+" and pass="+oldpass+""; 
            stat = conn.createStatement();
            int result = stat.executeUpdate(sql);
            return result;
        } catch (SQLException e1) {
            // TODO Auto-generated catch block
            System.out.println("修改失败！");
            //e1.printStackTrace();
        }  
        return 0;
    }
    public int delete(String id,String pwd){
        try {
            String sql="delete from user where id="+id+" and pass="+pwd+""; 
            stat = conn.createStatement();
            int result = stat.executeUpdate(sql);
            return result;
        } catch (SQLException e1) {
            // TODO Auto-generated catch block
            System.out.println("注销失败！");
            //e1.printStackTrace();
        }  
        return 0;
    }
    public ResultSet select(String id,String pwd){
        try {
            String sql="select * from user where id="+id+" and pass="+pwd+""; 
            stat = conn.createStatement();
            ResultSet result = stat.executeQuery(sql);
            return result;
        } catch (SQLException e1) {
            // TODO Auto-generated catch block
            System.out.println("登录失败");
            //e1.printStackTrace();
        }
        return null;
    }
}

最后那就是我们的主函数调用了：

具体的效果图如下：