java学生成绩管理系统源码.doc

文件addmessage.java代码： import java.awt.*; import java.awt.event.*; import java.sql.*; import java.util.*; import javax.swing.*; import javax.swing.table.*; class addmessage extends JFrame implements ActionListener{ JTextField t1,t2,t3,t4,t5; JTable table; JButton but1; JLabel lab1,lab2,lab3,lab4,lab5; JPanel p1; addmessage(){ super(增加); setBounds(350,100,470,400); setLayout(new GridLayout(1,1,10,10)); p1=new JPanel(); lab1=new JLabel(学号); t1=new JTextField(10); lab2=new JLabel(姓名); t2=new JTextField(10); lab3=new JLabel(课程名); t3=new JTextField(10); lab4=new JLabel(状态); t4=new JTextField(10); lab5=new JLabel(成绩); t5=new JTextField(10); but1=new JButton(添加); but1.addActionListener(this); p1.add(lab1); p1.add(t1); p1.add(lab2); p1.add(t2); p1.add(lab3); p1.add(t3); p1.add(lab4); p1.add(t4); p1.add(lab5); p1.add(t5); p1.add(but1); add(p1); setVisible(true); } public void actionPerformed(ActionEvent e){ int i=0 ; String sql1=null,sql2=null,update=null; String url=jdbc:mysql://localhost:3306/学生成绩系统; Connection con; Statement stmt; try{ Class.forName(org.gjt.mm.mysql.Driver); }catch(java.lang.ClassNotFoundException e1){ System.err.println(ClassNotFoundException:+e1.getMessage()); } if(e.getSource()==but1){ //添加------------------- try{ con=DriverManager.getConnection(url,root,123); stmt=con.createStatement(); sql1=INSERT INTO 学生成绩表 VALUES (+t1.getText()+,+t2.getText()+,+ t3.getText()+,+t4.getText()+,+t5.getText()+); String num1=t1.getText(); String num2=t1.getText(); String sele=select * from 学生成绩表 where 学号=+num1+ and 课程名=+num2+; ResultSet rs=stmt.executeQuery(sele); if(rs.next()){ JOptionPane.showMessageDia