Java+mysql 教务管理系统 带数据库

package com.student; import java.awt.*; import javax.swing.*; import javax.swing.border.TitledBorder; import java.awt.event.*; import java.sql.*; public class Login extends JFrame implements ActionListener { static JFrame m; JLabel lblUser = new JLabel("用户名："); JTextField txtuser = new JTextField(); JLabel lblPassword = new JLabel("密 码："); JPasswordField txtPassword = new JPasswordField(); JButton Enter = new JButton("登 录"); JButton Exit = new JButton("退 出"); ButtonGroup bg = new ButtonGroup(); JRadioButton student = new JRadioButton("学生"); JRadioButton teacher = new JRadioButton("老师"); JRadioButton user = new JRadioButton("管理员"); public Login() { m=new JFrame("登 录"); m.setResizable(false); Container contentPane=m.getContentPane(); JPanel p1 = new JPanel(); p1.setLayout(new GridLayout(1,4)); p1.setBorder(BorderFactory.createTitledBorder( BorderFactory.createLineBorder(Color.gray,2),"选择类别", TitledBorder.CENTER,TitledBorder.TOP)); bg.add(student); bg.add(teacher); bg.add(user); p1.add(student); p1.add(teacher); p1.add(user); JPanel p2=new JPanel(); p2.setLayout(new GridLayout(1,4)); p2.setBorder(BorderFactory.createTitledBorder( BorderFactory.createLineBorder(Color.gray,2),"请输入用户名和密码", TitledBorder.CENTER,TitledBorder.TOP)); p2.add(lblUser); p2.add(txtuser); p2.add(lblPassword); p2.add(txtPassword); JPanel p3=new JPanel(); p3.add(Enter); p3.add(Exit); contentPane.add(p1,BorderLayout.NORTH); contentPane.add(p2,BorderLayout.CENTER); contentPane.add(p3,BorderLayout.SOUTH); Enter.addActionListener(this); Exit.addActionListener(this); m.getRootPane().setDefaultButton(Enter); m.pack(); m.setBounds(100,100,400,180); m.setLocation(400, 100); m.setVisible(true); m.setLocationRelativeTo(null); m.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public void actionPerformed(ActionEvent e) { if(e.getSource()==Enter) { String username,password; username = new String(txtuser.getText()); password = new String(txtPassword.getPassword()); try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException ce) { JOptionPane.showMessageDialog(m,ce.getMessage()); } if(student.isSelected()) { try { Connection con = DriverManager.getConnection( "jdbc:mysql://localhost:3306/studentsystem", "root", "123"); Statement st = con.createStatement(); ResultSet rs = st.executeQuery("select * from student"); while(rs.next()) { if((rs.getString("Id").equals(username))&&(rs.getString("password").equals(password))) { StuOperation ss = new StuOperation(); break; } else { JOptionPane.showMessageDialog(m,"用户名或者密码错误"); break; } } rs.close(); st.close(); } catch (SQLException se) { JOptionPane.showMessageDialog(m,se.getMessage()); } } else if(teacher.isSelected()) { try { Connection con = DriverManager.getConnection( "jdbc:mysql://localhost:3306/studentsystem", "root", "123"); Statement st = con.createStatement(); ResultSet rs = st.executeQuery("select * from teacher"); while(rs.next()) { if((rs.getString("Id").equals(username))&&(rs.getString("password").equals(password))) { TeaOperation choose= new TeaOperation(); break; } else { JOptionPane.showMessageDialog(m,"用户名或者密码错误"); break; } } } catch (SQLException se) { JOptionPane.showMessageDialog(m,se.getMessage()); } } else if(user.isSelected()) { try { Connection con = DriverManager.getConnection( "jdbc:mysql://localhost:3306/studentsystem", "root", "123"); Statement st = con.createStatement(); ResultSet rs = st.executeQuery("select * from user"); while(rs.next()) { if((rs.getString("name").equals(username))&&(rs.getString("password").equals(password))) { UserOperation choose= new UserOperation(); break; } else { JOptionPane.showMessageDialog(m,"用户名或者密码错误"); break; } } } catch (SQLException se) { JOptionPane.showMessageDialog(m,se.getMessage()); } } } else { System.exit(0); } } public static void main(String[] args) { new Login(); } }