个人写的学生财务管理系统

package n1; import java.awt.*; import javax.swing.*; import java.awt.event.*; import java.sql.ResultSet; public class Login extends JFrame { private JLabel l1,l2,backimg; private JTextField user; private JPasswordField pwd; private JButton bt1,bt2; private ImageIcon img,logoimg; private Icon imgIcon; private Image logo; private DataBaseManager mydb; private ResultSet rs; public Login() { super("学生管理系统"); Container c = this.getContentPane(); logoimg = new ImageIcon("img/logo.gif"); logo = logoimg.getImage(); this.setIconImage(logo); c.setLayout(null); img = new ImageIcon("img/001.jpg"); imgIcon = img; backimg = new JLabel(imgIcon); l1 = new JLabel("用户名"); l2 = new JLabel("密码"); user = new JTextField(""); pwd = new JPasswordField(""); bt1 = new JButton("ok"); bt2 = new JButton("reset"); l1.setBounds(50,20, 60, 20); l2.setBounds(50,50,60,20); l1.setForeground(Color.red); l2.setForeground(Color.red); backimg.setBounds(0,0,300,200); user.setBounds(120,20,80,20); pwd.setBounds(120,50,80,20); bt1.setBounds(70,90,70,20); bt2.setBounds(140,90,70,20); bt1.setForeground(Color.red); bt2.setForeground(Color.red); // 添加组件到容器。 c.add(l1); c.add(l2); c.add(user); c.add(pwd); c.add(bt1); c.add(bt2); c.add(backimg); // 设置组件的属性（颜色，大小等）。 this.getRootPane().setWindowDecorationStyle(JRootPane.FRAME); //设置javaGUI. this.setUndecorated(true); //取掉标题栏. this.setResizable(false); //窗口大小固定，不可调整。 this.setSize(300,200); this.setLocation(200,200); this.setVisible(true); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //关闭窗口。 // 注册监听事件。 bt1.addActionListener(new ActionListener(){ @Override public void actionPerformed(ActionEvent e) { //检验用户名和密码。 checkLogin(); } }); // 敲Enter键登录。 pwd.addActionListener(new ActionListener(){ @Override public void actionPerformed(ActionEvent e) { //检验用户名和密码。 checkLogin(); } }); bt2.addActionListener(new ActionListener(){ @Override public void actionPerformed(ActionEvent e) { //检验用户名和密码。 reset(); } }); } public void checkLogin() { String user = this.user.getText().trim(); String pwd = new String(this.pwd.getPassword()); //注意返回类型。 try { mydb = DataBaseManager.getInstance(); rs = mydb.getResult("select * from admin where user = '" + user + "'"); if(rs.next()){ if(rs.getString("pwd").equals(pwd)) { this.dispose(); new MainFrame(); } else { JOptionPane.showMessageDialog(null, "密码不正确"); this.user.setText(""); this.pwd.setText(""); } } else { JOptionPane.showMessageDialog(null, "用户不存在"); this.user.setText(""); this.pwd.setText(""); } } catch(Exception e) { System.out.println("可能数据库有问题!"); } finally { mydb.closeConnection(); } /* if(user.equals("admin")) { if(pwd.equals("123")) { this.dispose(); //关掉前一个窗口，并释放内存。 // this.setVisible(false); //关掉前一个窗口，但不释放内存。 new MainFrame(); } else { JOptionPane.showMessageDialog(null, "密码不正确"); } } else { JOptionPane.showMessageDialog(null, "用户名不正确"); }*/ } private void reset() { this.user.setText(""); this.pwd.setText(""); } public static void main(String[] args) { new Login(); } }