学生选课管理系统【GUI/Swing+MySQL】（Java课设）

import javax.swing.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; /** * 增加信息 */ public class CourseChoose extends JFrame { public CourseChoose() { ////构造方法中界面设计 this.setTitle("选课界面"); this.setBounds(100, 100, 500, 700); this.setDefaultCloseOperation(DISPOSE_ON_CLOSE);//设置关闭子窗口但是不关闭父类窗口 this.setVisible(true); this.setLayout(null); JLabel jLabel = new JLabel("学生选课界面"); JLabel jLabel1 = new JLabel("选课的学号："); JLabel jLabel2 = new JLabel("选课的姓名："); JLabel jLabel3 = new JLabel("选课的班级："); JLabel jLabel4 = new JLabel("选课的课程名："); JLabel jLabel5 = new JLabel("选课的学分："); JButton jb1 = new JButton("选课"); JTextField field1 = new JTextField(18); JTextField field2 = new JTextField(18); JTextField field3 = new JTextField(18); JTextField field4 = new JTextField(18); JTextField field5 = new JTextField(18); JPanel jPanel = new JPanel(); JPanel jPanel1 = new JPanel(); JPanel jPanel2 = new JPanel(); JPanel jPanel3 = new JPanel(); JPanel jPanel4 = new JPanel(); JPanel jPanel5 = new JPanel(); JPanel jPanel0 = new JPanel(); jPanel.add(jLabel); jPanel1.add(jLabel1); jPanel1.add(field1); jPanel2.add(jLabel2); jPanel2.add(field2); jPanel3.add(jLabel3); jPanel3.add(field3); jPanel4.add(jLabel4); jPanel4.add(field4); jPanel5.add(jLabel5); jPanel5.add(field5); jPanel0.add(jb1); jPanel.setBounds(0, 80, 450, 50); jPanel1.setBounds(0, 150, 450, 50); jPanel2.setBounds(0, 220, 450, 50); jPanel3.setBounds(0, 290, 450, 50); jPanel4.setBounds(0, 360, 450, 50); jPanel5.setBounds(0, 430, 450, 50); jPanel0.setBounds(0, 500, 450, 50); this.add(jPanel); this.add(jPanel1); this.add(jPanel2); this.add(jPanel3); this.add(jPanel4); this.add(jPanel5); this.add(jPanel0); //添加按钮事件 jb1.addActionListener (new ActionListener() { public void actionPerformed(ActionEvent e) { //注册驱动 使用驱动连接数据库 Connection con = null; PreparedStatement stmt = null; ResultSet rs = null; try { boolean check = check(field1.getText()); if (check){ con = JDBCUtils.getConnection(); String sql = "insert into choose values(?,?,?,?,?)"; stmt = con.prepareStatement(sql); stmt.setString(1, field1.getText()); stmt.setString(2, field2.getText()); stmt.setString(3, field3.getText()); stmt.setString(4, field4.getText()); stmt.setString(5, field5.getText()); stmt.execute(); JOptionPane.showMessageDialog(null, "选课成功！"); }else { JOptionPane.showMessageDialog(null, "你的学分已经修满！"); } } catch (Exception e2) { e2.printStackTrace(); }finally { try { JDBCUtils.close(rs, stmt, con); } catch (SQLException throwables) { throwables.printStackTrace(); } } } }); } //检查学分有没有修满（修满为8学分） private boolean check(String sid) throws SQLException { Connection conn =JDBCUtils.getConnection(); String sql = "select sum(credit) sum from choose group by sid having sid=?"; PreparedStatement pstm = conn.prepareStatement(sql); pstm.setString(1, sid); // 执行查询 ResultSet rs = pstm.executeQuery(); if(rs.next()){ String sum = rs.getString("sum"); double i = Double.parseDouble(sum); if(i<=8){ return true; }else { return false; } }else { //还未选课 return true; } } }