chengjiguanli.java

该项目的开发是在学生课程日益增多的压力下设计且用来解决选课的烦恼

import java.awt.*;
import java.sql.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
public class chengjiguanli extends JFrame implements ActionListener 
{
  Connection con;
  ResultSet rs;
  Statement st;
  JButton button1,button2,button3;
  JTextField text1,text3;
  Choice kc;
  String sid1=new String();
  String crname2=new String();
  String studentid1=new String();
  int count=0;

  public void chengjiguanli()
  {
   text1=new JTextField(10);
   kc=new Choice();
   text3=new JTextField(10);
   button1=new JButton("查询");
   button1.addActionListener(this);
   button2=new JButton("添加");
   button2.addActionListener(this);
   button3=new JButton("退出");
   button3.addActionListener(this);

   Box box1=Box.createHorizontalBox();
   box1.add(new JLabel("成绩管理页面",JLabel.CENTER));
   Box box2=Box.createHorizontalBox();
   box2.add(new JLabel("学号：",JLabel.CENTER));
   box2.add(text1);
   Box box3=Box.createHorizontalBox();
   box3.add(new JLabel("课程：",JLabel.CENTER));
   box3.add(kc);
   Box box4=Box.createHorizontalBox();
   box4.add(new JLabel("成绩：",JLabel.CENTER));
   box4.add(text3);

   Box boxH=Box.createVerticalBox();
   boxH.add(box1);
   boxH.add(box2);
   boxH.add(box3);
   boxH.add(box4);
   boxH.add(Box.createVerticalGlue());
   JPanel pCenter=new JPanel();
   pCenter.add(boxH);
   setLayout(new BorderLayout());
   add(pCenter,BorderLayout.CENTER);

   JPanel pSouth=new JPanel();
   pSouth.add(button1);
   pSouth.add(button2);
   pSouth.add(button3);
   add(pSouth,BorderLayout.SOUTH);

   setVisible(true);
   setBounds(100,50,300,200);
   validate();

  }

  public void actionPerformed(ActionEvent e)
  { if(e.getSource()==button1)
    {      try{//连接数据库
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
       }
            catch(ClassNotFoundException e2)
                {
                 System.out.println(""+e2);
                }
       try{
           con=DriverManager.getConnection("jdbc:odbc:lhm","","");
           st=con.createStatement();
           rs=st.executeQuery("Select * FROM xuanke");
          }catch(SQLException el){}//连接数据库
          try{//将后台数据库中的学生所选的课程名显示在kc这个按钮上
          String id=new String();
          id=text1.getText();
          
          while(rs.next())
           {String id1=new String();
            id1=rs.getString("studentid");
            if(id.equals(id1))
            {String kechengming=new String();
             kechengming=rs.getString("crname");
             kc.add(kechengming);
             count++;
            }  
           }
          }catch(Exception exx){}
        if(count==0){JOptionPane.showMessageDialog(null,"该生没有选修任何课程！");}
        }

    if(e.getSource()==button2)
    {try{//连接数据库
            Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
           }
            catch(ClassNotFoundException e2)
                {
                 System.out.println(""+e2);
                }
     try{
           con=DriverManager.getConnection("jdbc:odbc:lhm","","");
           st=con.createStatement();
           rs=st.executeQuery("Select * FROM xuanke");
          }
           catch(SQLException el){}//连接数据库 
     String id1=new String();//提取学生学号    
     id1=text1.getText();
     int count=0;
  

     String crname1=new String();
     crname1=kc.getSelectedItem();
     String crcode1=new String();
     crcode1=text3.getText();

     try{

         while(rs.next())
         {crname2=rs.getString("crname");
          studentid1=rs.getString("studentid");
          if((id1.equals(studentid1))&&(crname1.equals(crname2)))
            {String strSQL3 ="update xuanke set crcode='"+crcode1+"'"+"where studentid='"+id1+"'and crname='"+crname1+"'";      
             try
                {
                 st.executeUpdate(strSQL3);
                 }catch(Exception exx){}
             JOptionPane.showMessageDialog(null,"添加成功！");
             text3.setText("");
             }
          }
         }catch(Exception exxx){}
           
      } 
     if(e.getSource()==button3){System.exit(0);} 
  }

}