Java--登陆注册系统(数据库)
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
public class DengLu extends JFrame implements ActionListener,KeyListener,ItemListener,FocusListener{
JLabel top,bott;
JComboBox combobox;
JPasswordField password;
JButton b_login,b_regedit;
JPanel panelMain,panel_center;
public DengLu (){
super("登陆系统");
panelMain = new JPanel(new BorderLayout(10, 10)){
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D)g;
super.paintComponent(g);
Image img = Toolkit.getDefaultToolkit().getImage("G:\\image\\Denglubg.jpg");
g2.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
}
};
top = new JLabel ();
top.setPreferredSize(new Dimension(this.getWidth(),30));
bott = new JLabel ();
bott.setForeground(Color.white);
bott.setPreferredSize(new Dimension(this.getWidth(),25));
centerBuild();
additem();
panelMain.add(top,BorderLayout.NORTH);
panelMain.add(bott,BorderLayout.SOUTH);
panelMain.add(panel_center,BorderLayout.CENTER);
combobox.addItemListener(this);
password.addActionListener(this);
b_login.addActionListener(this);
b_regedit.addActionListener(this);
combobox.addFocusListener(this);
password.addFocusListener(this);
b_login.addFocusListener(this);
b_regedit.addFocusListener(this);
combobox.addKeyListener(this);
password.addKeyListener(this);
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent we) {
quit();
}
});
this.setContentPane(panelMain); //设置窗口面板
this.setSize(350, 235);
Dimension frm=this.getSize();
Dimension scr=Toolkit.getDefaultToolkit().getScreenSize();
this.setLocation((scr.width-frm.width)/2,(scr.height-frm.height)/2);
this.setResizable (false); //设置窗口不可放大缩小
this.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE);
//sunswing.setWindowCenter(this);
this.setVisible(true);
//password.requestFocus(true); //设置焦点给密码框}
private void centerBuild(){
JLabel L1,L2;
panel_center=new JPanel(null);
panel_center.setOpaque(false);
L1=new JLabel("用户名:");
L1.setForeground(Color.white);
L2=new JLabel("登录密码:");
L2.setForeground(Color.white);
b_login=new JButton("登陆");
b_regedit=new JButton("注册");
combobox=new JComboBox();
combobox.addItem("");
password=new JPasswordField();
L1.setBounds(50,14,60,20);
L2.setBounds(50,48,60,20);
b_login.setBounds(68,87,86,28);
b_regedit.setBounds(186,87,86,28);
combobox.setBounds (115,12,171,23);
password.setBounds (115,46,170,23);
combobox.setEditable(true);
panel_center.add(L1);
panel_center.add(L2);
panel_center.add(b_login);
panel_center.add(b_regedit);
panel_center.add(combobox);
panel_center.add(password);
}
private void quit(){
int flag = 0;
String msg = "您现在要关闭系统吗？";
flag = JOptionPane.showConfirmDialog(null, msg, "提示", JOptionPane.YES_NO_OPTION);
if(flag == JOptionPane.YES_OPTION) {
this.setVisible(false);
System.exit(0);
}
}
/**=======================================================================* *
* 【## private void zhuce】注册用户界面
* 参数：无
* 返回值：无
* 权限：private
* 功能：通过“用户名,登陆密码”进行用户注册
**=======================================================================** */
private void zhuce(){
String utext=String.valueOf(combobox.getSelectedItem());
String ptext=password.getText();
if(utext.trim().equals("")||ptext.equals("")){
JOptionPane.showMessageDialog(null,"用户名、登陆密码不能为空！",
"警告",https://www.doczj.com/doc/3f11316204.html,RMATION_MESSAGE);
}
else{
Connection conn = null;
PreparedStatement ps=null;
ResultSet rs=null;
try{
conn=Utils.getConnection();
String sql="select users from login.dlu where users=?";
ps=conn.prepareStatement(sql);
ps.setString(1, utext);
rs=ps.executeQuery();
if(rs.next()){ //用户存在
JOptionPane.showMessageDialog(null,"该用户已注册,请重新输入用户名注册,\n或者直接登录!",
"提醒",https://www.doczj.com/doc/3f11316204.html,RMATION_MESSAGE);
}
else{
if(ptext.length()>=6){
sql="insert into login.dlu (users,passwords)values(?,?)";
ps=conn.prepareStatement(sql);
ps.setString(1, utext);
ps.setString(2, ptext);
int up=ps.executeUpdate();
if(up==1){
JOptionPane.showMessageDialog(null,"注册成功,\n可以直接登录!",
"提醒",https://www.doczj.com/doc/3f11316204.html,RMATION_MESSAGE);
bott.setText("已注册成功！请登录！");
combobox.removeAllItems();
additem();
}
}
else{
bott.setText("提示：密码不能小于六位数!");
}
}
}
catch(Exception e){
throw new RunException(e.getMessage(),e);
}
finally{
Utils.free(rs, ps, conn);
}
}
}
/**=======================================================================* *
* 【## private void additem()】增加最后登录用户的7名
* 参数：无
* 返回值：无
* 权限：private
* 功能：模仿qq的登录记录功能
**=======================================================================** */
private void additem(){
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
conn=Utils.getConnection();
String sql="select users from login.dlu";
ps=conn.prepareStatement(sql);
rs=ps.executeQuery();
rs.afterLast();
int i=0;
String s=null;
while(rs.previous()&& i<8){
i++;
s=rs.getString("users");
combobox.addItem(s);
}
} catch (SQLException e) {
throw new RunException(e.getMessage(),e);
}
finally{
Utils.free(rs, ps, conn);
}
}
private void getPassword(){
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
String ut=String.valueOf(combobox.getSelectedItem());
try {
conn=Utils.getConnection();
String sql="select users,passwords from login.dlu where users=?";
ps=conn.prepareStatement(sql);
ps.setString(1, ut);
rs=ps.executeQuery();
String s1=null;
while(rs.next()){
s1=rs.getString("passwords");
}
password.setText(s1);
} catch (SQLException e) {
throw new RunException(e.getMessage(),e);
}
finally{
Utils.free(rs, ps, conn);
}
}
/**=======================================================================* *
* 【## private void denglu】登陆界面
* 参数：无
* 返回值：无
* 权限：private
* 功能：密码验证通过，进入主操作界面，仅类内使用
**=======================================================================** */
private void denglu(){
String utext=String.valueOf(combobox.getSelectedItem());
String ptext=password.getText();
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
conn=Utils.getConnection();
String sql="select users,passwords from login.dlu where users=?";
ps=conn.prepareStatement(sql);
ps.setString(1, utext);
rs=ps.executeQuery();
if(rs.next()){
if(ptext.equals(rs.getString(2))){
this.setVisible(false);
new MainProgram();
System.exit(1);
}
else{
JOptionPane.showMessageDialog(null,"您输入的用户和密码不正确，\n请重新输入",
"错误", JOptionPane.ERROR_MESSAGE);
}
}
else{
JOptionPane.showMessageDialog(null,"您输入的用户不存在，请重新输入，\n或者先注册",
"错误", https://www.doczj.com/doc/3f11316204.html,RMATION_MESSAGE);
}
} catch(Exception e){
throw new RunException(e.getMessage(),e);
}
finally{
Utils.free(rs, ps, conn);
}
}
/**=======================================================================* *
* ActionListener 监听
**=======================================================================** */
public void actionPerformed(ActionEvent en){
if(en.getSource()==b_regedit){
zhuce();
}
else if(en.getSource()==b_login){
denglu();
}
}
/**=======================================================================* *
* ItemListener 监听
**=======================================================================** */
public void itemStateChanged(ItemEvent es){
getPassword();
password.requestFocus(true);
}
/**=======================================================================* *
* FocusListener 监听
**=======================================================================** */
public void focusGained(FocusEvent fe){
if(fe.getSource()==combobox){
bott.setText("提示：请输入用户名！");
}
else if(fe.getSource()==password){
bott.setText("提示：请输入密码！密码必须大于六位数");
}
else if(fe.getSource()==b_login){
bott.setText("提示：登录系统！");
}
else if(fe.getSource()==b_regedit){
bott.setText("提示：注册账号");
}
}
public void focusLost(FocusEvent esd){}
/**=======================================================================* *
* KeyListener 监听
**=======================================================================** */
public void keyPressed(KeyEvent ke){
if(ke.getKeyChar()==KeyEvent.VK_ENTER){
if(ke.getSource()==combobox){
password.requestFocus(true);
}
if(password.getPassword().length>0){
denglu();
}
}else if(ke.getKeyChar() == KeyEvent.VK_ESCAPE) { //按ESC键退出系统quit();
}
}
public void keyReleased(KeyEvent kr){}
public void keyTyped(KeyEvent kt){}
/**=======================================================================* *
* 主函数main 接入口
**=======================================================================** */
public static void main(String args[]){
new DengLu();
}
}
class RunException extends RuntimeException {
public RunException() {
// TODO Auto-generated constructor stub
}
public RunException(String message) {
super(message);
// TODO Auto-generated constructor stub
}
public RunException(Throwable cause) {
super(cause);
// TODO Auto-generated constructor stub
}
public RunException(String message, Throwable cause) {
super(message, cause);
// TODO Auto-generated constructor stub
}
}
class Utils {
private static String url="jdbc:mysql://localhost:3306/login";
private static String user="root";
private static String password="136597";
private Utils(){}
static{
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (Exception e) {
throw new RunException(e.getMessage(),e);
}
}
static Connection getConnection(){
try {
return DriverManager.getConnection(url,user,password);
} catch (SQLException e) {
throw new RunException(e.getMessage(),e);
}
}
public static void free(ResultSet rs,PreparedStatement ps,Connection conn){ try{
if(ps!=null){
ps.close();
}
}catch(Exception e){
e.printStackTrace();
}
try{
if(rs!=null){
rs.close();
}
}catch(Exception e){
e.printStackTrace();
}
try{
if(conn!=null){
conn.close();
}
}catch(Exception e){
e.printStackTrace();
}
}
}
配置好数据库驱动，运行就可以了！