kechengguanli.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 kechengguanli extends JFrame implements ActionListener 
{
    
  Connection con;
  ResultSet rs;
  Statement st;
  JButton button1,button2,button3,button4;
  JTextField text1,text2,text3,text4;
  String crid1=new String();
  String crname1=new String();
  String crper1=new String();
  String crcre1=new String();
   

  public void kechengguanli()
  {
   text1=new JTextField(10);
   text2=new JTextField(10);
   text3=new JTextField(10);
   text4=new JTextField(10);
   button1=new JButton("查看");
   button1.addActionListener(this);
   button2=new JButton("添加");
   button2.addActionListener(this);
   button3=new JButton("删除");
   button3.addActionListener(this);
   button4=new JButton("退出");
   button4.addActionListener(this);

   Box box1=Box.createHorizontalBox();
   box1.add(new JLabel("课程管理页面",JLabel.CENTER));
   Box box2=Box.createHorizontalBox();
   box2.add(new JLabel("课名：",JLabel.CENTER));
   box2.add(text1);
   Box box3=Box.createHorizontalBox();
   box3.add(new JLabel("课号：",JLabel.CENTER));
   box3.add(text2);
   Box box4=Box.createHorizontalBox();
   box4.add(new JLabel("学时：",JLabel.CENTER));
   box4.add(text3);
   Box box5=Box.createHorizontalBox();
   box5.add(new JLabel("学分：",JLabel.CENTER));
   box5.add(text4);

   Box boxH=Box.createVerticalBox();
   boxH.add(box1);
   boxH.add(box2);
   boxH.add(box3);
   boxH.add(box4);
   boxH.add(box5);
   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);
   pSouth.add(button4);
   add(pSouth,BorderLayout.SOUTH);

   setVisible(true);
   setBounds(100,50,400,300);
   validate();
  }

  public void actionPerformed(ActionEvent e)
  { 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 kecheng");
          }
           catch(SQLException el){}//连接数据库

    if(e.getSource()==button1)
    {
     String crname=new String();//提取课程名
     crname=text1.getText();
     int count=0;

    try{
        while(rs.next())
        {crname1=rs.getString("crname");
         if(crname1.equals(crname))
           {crid1=rs.getString("crid");
            crper1=rs.getString("crper");
            crcre1=rs.getString("crcre");
            text2.setText(crid1);
            text3.setText(crper1);
            text4.setText(crcre1);
            ++count;
            }
         }
        }catch(Exception ee){}
     if(count==0){JOptionPane.showMessageDialog(null,"该学期未开这么课程！");text1.setText("");}
    }
    if(e.getSource()==button2)
    {

     String crid2=new String();
     crid2=text2.getText();
     String crname2=new String();
     crname2=text1.getText();
     String crper2=new String();
     crper2=text3.getText();
     String crcre2=new String();
     crcre2=text4.getText();


     if((crid2.length()>0)&&(crname2.length()>0)&&(crper2.length()>0)&&(crcre2.length()>0))
     {int count=0;
      try{
          while(rs.next())
          { String crid3=new String();
            crid3=rs.getString("crid");
            if(crid2.equals(crid3)){count++;}
          }
         }catch(Exception exxx){}
      if(count==0)
      {
       String strSQL6 ="insert into kecheng(crid,crname,crper,crcre) values('" + crid2 + "','" + crname2 + "','" + crper2+"','" + crcre2+"')";
       try{
          st.executeUpdate(strSQL6);
         }catch(Exception exx){}
       JOptionPane.showMessageDialog(null,"添加成功！");
      }
      else{JOptionPane.showMessageDialog(null,"课程号已存在，请重新填写！");}
     }
     else{JOptionPane.showMessageDialog(null,"请完整填写课程信息");}
    }
    if(e.getSource()==button3) 
    { 
     String m="确定要删除该门课程吗?"; 
     int ok=JOptionPane.showConfirmDialog(this,m,"确认",JOptionPane.YES_NO_OPTION,JOptionPane.QUESTION_MESSAGE);  
     if(ok==JOptionPane.YES_OPTION)
     {String crname2=new String();
      crname2=text1.getText();
      String strSQL5 ="delete from kecheng where crname='"+crname2+"'";
      try
        {
         st.executeUpdate(strSQL5);
        }catch(Exception exxxx){}
      JOptionPane.showMessageDialog(null,"删除成功！");
     }
    }
  if(e.getSource()==button4){setVisible(false);}
  }

}