用javaSwing和mysql数据库做的一个登录页面
用javaSwing和mysql数据库做的一个登录页面
一：首先在eclipse中新建一个java工程
二：然后新建一个包，并且在包中新建两个类：一个事登录用的界面(Login)类，一个事连接数据库的(jdbc)类我建立的是p4这个包
三：导入包mysql-connector-java-5.1.41-bin.jar并且要添加到构建路径不添加到构建路径项目工程不会读出来的
四：编写那个界面Login类
那个界面类的源代码如下：
package p4;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
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 Login extends JFrame implements ActionListener {
private JPanel pan = new JPanel();
private JLabel namelab = new JLabel("用户名");
private JLabel passlab = new JLabel("密 码");
private JTextField nametext = new JTextField();
private JPasswordField passtext = new JPasswordField();
public JButton denglu = new JButton("登录");
public JButton zhuce = new JButton("注册");
public JButton updatepass = new JButton("修改密码");
public JButton deleteuser = new JButton("删除用户");
public Login(){
Font font = new Font("宋体",Font.BOLD,12);
super.setTitle("欢迎登录本系统");
pan.setLayout(null);
namelab.setBounds(20,20,60,30);
nametext.setBounds(90,20,140,30);
passlab.setBounds(20,60,60,30);
passtext.setBounds(90,60,140,30);
denglu.setBounds(30,120,90,20);
zhuce.setBounds(140,120,90,20);
updatepass.setBounds(30,150,90,20);
deleteuser.setBounds(140,150,90,20);
pan.add(namelab);
pan.add(nametext);
pan.add(passlab);
pan.add(passtext);
pan.add(denglu);
pan.add(zhuce);
pan.add(updatepass);
pan.add(deleteuser);
passtext.setFont(font);
zhuce.setFont(font);
updatepass.setFont(font);
deleteuser.setFont(font);
denglu.addActionListener(this);
zhuce.addActionListener(this);
updatepass.addActionListener(this);
deleteuser.addActionListener(this);
super.add(pan);
super.setSize(300,250);
super.setVisible(true);
}
public static void main(String []args){
new Login();
}
@Override
public void actionPerformed(ActionEvent arg0) {
if(arg0.getSource()==denglu){
denglu();
}else if (arg0.getSource()==zhuce){
zhuce();
}else if (arg0.getSource()==updatepass){
updatepass();
}else if (arg0.getSource()==deleteuser){
deleteuser();
}
}
//登录按钮的事件处理函数
public void denglu(){
Jdbcs d =new Jdbcs();
String username = nametext.getText();
String password = passtext.getText();
if(d.compare(username, password)){
aJOptionPane.showMessageDialog(null,"登录成功！");
super.setVisible(false);
}
}
//注册按钮触发后的事件处理函数
public void zhuce(){
Jdbcs d =new Jdbcs();
String username = nametext.getText();
String password = passtext.getText();
d.insert(username,password);
}
//修改密码按钮触发后的事件处理函数
public void updatepass(){
pan.setEnabled(false);
JFrame frame1 = new JFrame("密码修改");
frame1.setSize(250, 200);
JPanel updatepass = new JPanel();
JLabel namelab1 = new JLabel("用户名");
JLabel passlab1 = new JLabel("旧密码");
JLabel newpasslab = new JLabel("新密码");
JTextField nametext1 = new JTextField(""+nametext.getText());
JPasswordField passtext1 = new JPasswordField();
JPasswordField newpasstext = new JPasswordField();
JButton ok = new JButton("修改");
JButton resert = new JButton("重置");
updatepass.setLayout(null);
namelab1.setBounds(5,5,70,20);
nametext1.setBounds(80,5,120,20);
passlab1.setBounds(5,30,70,20);
passtext1.setBounds(80,30,120,20);
newpasslab.setBounds(5,60,70,20);
newpasstext.setBounds(80,60,120,20);
ok.setBounds(10,110,60,20);
resert.setBounds(90,110,60,20);
updatepass.add(namelab1);
updatepass.add(nametext1);
updatepass.add(passlab1);
updatepass.add(passtext1);
updatepass.add(newpasslab);
updatepass.add(newpasstext);
updatepass.add(ok);
updatepass.add(resert);
frame1.add(updatepass);
frame1.setVisible(true);
ok.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent arg0) {
Jdbcs d =new Jdbcs();
String username = nametext1.getText();
String password1 = passtext1.getText();
String newpassword = newpasstext.getText();
if(d.update(username,password1,newpassword)){
frame1.setVisible(false);
}
}
});
//重置文本框 里的内容
resert.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent arg0) {
nametext1.setText("");
passtext1.setText("");
newpasstext.setText("");
}
});
}
//删除用户按钮触发后的事件处理函数
public void deleteuser(){
String username = nametext.getText();
String password = passtext.getText();
Jdbcs s = new Jdbcs();
s.delete(username,password);
}
}
五：写连接数据库的代码以及用到的操作的源代码
jdbc这个类的源代码如下：
package p4;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.swing.JOptionPane;
public class Jdbc {
Connection con = null;
Statement statement = null;
ResultSet res = null;
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/user";
String name = "root";
String passwd = "123456";
public Jdbc(){
try{
Class.forName(driver).newInstance();
con = DriverManager.getConnection(url,name,passwd);
statement = con.createStatement();
}catch(ClassNotFoundException e){
System.out.println("对不起，找不到这个Driver");
e.printStackTrace();
}catch(SQLException e){
e.printStackTrace();
}catch(Exception e){
e.printStackTrace();
}
}
//对用户信息的修改实际上就是对密码的修改
public boolean update(String username1,String password1,String newpassword){
boolean judge = false;
boolean s =compare(username1,password1);
if(s){
String sql = "update user set password=\""+newpassword+"\"where username=\""+username1+"\"";
try {
int a = statement.executeUpdate(sql);
if(a==1){
JOptionPane.showMessageDialog(null,"密码修改成功！");
judge = true;
}
con.close();
statement.close();
} catch (SQLException e) {
JOptionPane.showMessageDialog(null, "用户不存在！");
e.printStackTrace();
}
}
else{
JOptionPane.showMessageDialog(null, "修改失败");
}
return judge;
}
//删除用户信息
public void delete(String username,String password){
if(compare(username,password)){
JOptionPane.showMessageDialog(null,"已经完成删除");
}else{
return;
}
String sql = "delete from user where username=\""+username+"\"";
try{
int a = statement.executeUpdate(sql);
con.close();
statement.close();
}catch(SQLException e){
JOptionPane.showMessageDialog(null,"不存在该用户！");
e.printStackTrace();
}
}
//用户注册功能的实现，添加数据
public void insert(String username,String password){
String sql = "insert into user(username,password) values(\""+username+"\",\""+password+"\")";
try{
int a = statement.executeUpdate(sql);
con.close();
statement.close();
if(a==1){
JOptionPane.showMessageDialog(null,"注册成功！");
}
}catch(SQLException e){
JOptionPane.showMessageDialog(null, "对不起该用户名已经有了！");
e.printStackTrace();
}
}
//对比用户名和密码是不匹配
public boolean compare(String username,String password){
boolean m = false;
String sql = "select password from user where username=\""+username+"\"";
try{
res = statement.executeQuery(sql);
if(res.next()){
String pa = res.getString(1);
System.out.println(pa+" " +password);
if(pa.equals(password)){
m = true;
}else {
JOptionPane.showMessageDialog(null, "密码错误！");
}
}else {
JOptionPane.showMessageDialog(null, "用户名不存在！");
}
res.close();
con.close();
statement.close();
}catch(SQLException e){
e.printStackTrace();
}
return m;
}
}
六：代码写完了 但是数据库还没有建立吧，那就建立数据库吧
先建立一个数据库
用到命令是
create database user;
然后新建一个表：
use user;
create table user(username varchar(20) primary key, password varchar(20));
现在表是空的，往表中添加几个数据：
insert into user(username,password) values("A",“123456”),("B","asdfg");
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