delcourseinfohandler.java

在本系统中

//删除课程信息。在删除课程信息的过程中，需要判断该课程是否已经存在于课程成绩信息，
//且属于没有完成的状态。如果存在且为未完成状态，则不允许删除；如果存在且为完成状态，允许删除；
//如果不存在，允许删除，同时删除开课信息和选课信息中的该课程信息。



package jin.handler;

import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;

import jin.internalFrame.*;
import jin.dao.*;
import jin.bean.*;

public class DelCourseInfoHandler
{
	private DelCourseInfo delCourseInfo; 
	
	private JComboBox comboBox;
	private JTextField[] fields;
	
	public DelCourseInfoHandler(DelCourseInfo delCourseInf)
	{
		this.delCourseInfo=delCourseInf;
		fields=delCourseInfo.getFields();
		comboBox=delCourseInfo.getComboBox();
		
		String sql1="select * from courseInfo";
		CourseInfoDAO courseInfoDAO=new CourseInfoDAO();
		ArrayList courseList=courseInfoDAO.excuteQuery(sql1);
		CourseInfoBean courseInfoBean=null;
		
		for(int i=0;i<courseList.size();i++)
		{
			courseInfoBean=(CourseInfoBean)courseList.get(i);
			comboBox.addItem(courseInfoBean.getCourseID());
		}
		
		
		comboBox.addActionListener
		(
			new ActionListener()
			{
			
				public void actionPerformed(ActionEvent e)
				{				
					String sql="select * from courseInfo where courseID='"+comboBox.getSelectedItem().toString().trim()+"'";
					CourseInfoDAO courseInfoDAO=new CourseInfoDAO();
					ArrayList courseList=courseInfoDAO.excuteQuery(sql);
					
					CourseInfoBean courseInfoBean=null;
					if(courseList.size()!=0)
					{
						courseInfoBean=(CourseInfoBean)courseList.get(0);
						fields[0].setText(courseInfoBean.getCourseName());
						fields[1].setText(courseInfoBean.getMajorID());
						fields[2].setText(courseInfoBean.getState());
					}		
				}
			}			
		);
			


		delCourseInfo.getButtonsPanel().getButton(0).addActionListener
		(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent e)
				{	
					if(fields[2].getText().trim().equals("在编"))
					{
						JOptionPane.showMessageDialog(null,"不能删除该课程信息!");
					}
					
					else
					{
						boolean BOK=false;
						String sql1="delete * from courseInfo where courseID='"+comboBox.getSelectedItem().toString().trim()+"'";
						CourseInfoDAO courseInfoDAO=new CourseInfoDAO();
						BOK=courseInfoDAO.delete(sql1);
						if(BOK)
						{
							String sql2="select * from openCourseInfo where courseID='"+comboBox.getSelectedItem().toString().trim()+"'";
							OpenCourseInfoDAO openCourseInfoDAO=new OpenCourseInfoDAO();
							ArrayList openCourList=openCourseInfoDAO.excuteQuery(sql2);
							OpenCourseInfoBean openCourseInfoBean=(OpenCourseInfoBean)openCourList.get(0);
							
							
							String sql3="delete * from openCourseInfo where courseID='"+comboBox.getSelectedItem().toString().trim()+"'";
							BOK=openCourseInfoDAO.delete(sql3);
							if(BOK)
							{
								String sql4="delete * from choiceCourseInfo where openCourseID='"+openCourseInfoBean.getOpenCourseID()+"'";
								ChoiceCourseInfoDAO choiceCourseInfoDAO=new ChoiceCourseInfoDAO();
								BOK=choiceCourseInfoDAO.delete(sql4);
								if(BOK)
								{
									//要不要删除课程成绩信息表中的
									String sql5="delete * from courseScoreInfo where courseID='"+comboBox.getSelectedItem().toString().trim()+"'";
									CourseScoreInfoDAO courseScoreInfoDAO=new CourseScoreInfoDAO();
									BOK=courseScoreInfoDAO.delete(sql5);
									if(BOK)
									{
										JOptionPane.showMessageDialog(null,"删除该课程信息成功!");
									}
									
									else
									{
										JOptionPane.showMessageDialog(null,"删除该课程信息失败!");
									}
								}
								else
								{
									JOptionPane.showMessageDialog(null,"删除该课程信息失败!");
								}
								
							}
							
							else
							{
								JOptionPane.showMessageDialog(null,"删除该课程信息失败!");
							}
						}
						
						else
						{
							JOptionPane.showMessageDialog(null,"删除该课程信息失败!");
						}
					}				
					
					delCourseInfo.setVisible(false);						
				}
			}
		);
	}
}