xuankexinxi.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 xuankexinxi extends  JFrame implements ActionListener
{
  Connection con;
  ResultSet rs;
  Statement st;	
  JTextField text1;
  JButton button1,button2;
  TextArea ta;

  String id1=new String();
  String kechengming=new String();
  String chengji=new String();
  
  public void xuankexinxi()
  {
   text1=new JTextField(10);
   ta=new TextArea("无信息",5,30);
   button1=new JButton("查询");
   button1.addActionListener(this);
   button2=new JButton("退出");
   button2.addActionListener(this);
   Box box1=Box.createHorizontalBox();
   box1.add(new JLabel("个人选课情况",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("选课情况",JLabel.CENTER));
   box3.add(ta);
   Box boxH=Box.createVerticalBox();
   boxH.add(box1);
   boxH.add(box2);
   boxH.add(box3);
   JPanel pCenter=new JPanel();
   pCenter.add(boxH);
   setLayout(new BorderLayout());
   add(pCenter,BorderLayout.CENTER);
   JPanel pSouth=new JPanel();
   pSouth.add(button1);
   pSouth.add(button2);
   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
       String id=new String();
       id=text1.getText();
       String s=""                              ;
       if(id.length()>0 )
       {
        try{
            while(rs.next())
            {id1=rs.getString("studentid");
             if(id.equals(id1))
              {kechengming=rs.getString("crname");
               chengji=rs.getString("crcode");
               s=s+kechengming+"该课程成绩为："+chengji+";";
              }
             }
            if(s.length()==0){JOptionPane.showMessageDialog(null,"该学生还没选课！");}
             else{ta.setText("该学生所选课程为："+s);}
            }catch(Exception ee){}
       }
      }
     if(e.getSource()==button2){setVisible(false);}
   }

}