course.java

这是书上的<java毕业设计指南与项目实践>的第6章:基于JSP+JavaBean+Servlet的课程管理系统,供大家参考

package com.course;
import java.sql.*;
public class course {  
  //定义课程相关的信息
  private String id;
  private String name;
  private String dep;
  private String prepare;
  private int mark;
  
  public void setPrepare(String s){prepare=s;}
  public String getPrepare(){return prepare;}
  public void setMark(int s){mark=s;}
  public int getMark(){return mark;}
  public void setDep(String s){dep=s;}
  public String getDep(){return dep;}
  public String getId() {
    return id;
  }
  public void setId(String id) {
    this.id = id;
  }
  public String getName() {
    return name;
  }
  public void setName(String name) {
    this.name = name;
  }
   //得到所能选择的预修课
  public ResultSet getPrepares(){               
 	String sql="select name,id from course   ";
 	sqlBean db = new sqlBean();
 	ResultSet rs = db.executeQuery(sql);
 	return rs; 	
 	}
 	
    //查看预修课所在的系	
 	public String getPrepareDep(){                 
 		String s="no";
 	String sql="select dep from course where id='"+prepare+"' ";
 	sqlBean db = new sqlBean();
 	try{
 	ResultSet rs = db.executeQuery(sql);
 	if(rs.next()){
 	   s=rs.getString("dep");  	   			
 		}
 	}catch(Exception e){ e.getMessage();}		
 	return s;}
 	
    //查看所有课程
    public ResultSet  getCourse(){         
		String sql="select * from course   ";
		sqlBean db= new sqlBean();
		ResultSet rs = db.executeQuery(sql);
		 return rs;
		                         }
		                         
	//删除课程	                         
    public int deleteCourse(String id){  
        int num=0; 	
    	String sql="delete  from Course where id ='"+id+"' ";
    	sqlBean db= new sqlBean();
        num=db.executeDelete(sql);
        return num;
    	}                                           	
     // 根据课程ID查看预修课所在的系
 	public String getPrepareDep(String id){
 		String dep="";
 		String sql="select dep from course where id='"+id+"'";
 		sqlBean db= new sqlBean();
 		try{
 		ResultSet rs = db.executeQuery(sql);
 		if(rs.next()) 
 		dep=rs.getString("dep");
 	       }catch(SQLException e){System.out.print(e.toString());}
 		return dep;
 		}
 	//更新课程信息
    public void updateCourse(String id){    	
      String sql="update course "+
                 " set name='"+name+"',prepare='"+prepare+"',"+
                 "dep='"+dep+"',mark='"+mark+"'  "+
                 " where id='"+id+"' ";
                 sqlBean db= new sqlBean();
                 db.executeInsert(sql);
                 }
    	
    //添加课程	
 	public void addCourse(){      
 		String sql="insert into course(id,name,mark,prepare,dep) "+
 		           "VALUES('"+id+"','"+name+"','"+mark+"','"+prepare+"','"+dep+"') ";
 		 sqlBean db = new sqlBean();
 		 db.executeInsert(sql);           
 		                  }	
 	//判断某门课程是否存在
    public boolean hasLogin( String id){
    	boolean f=true;
    	String sql="select id from course where id='"+id+"'  ";
    	sqlBean db = new sqlBean();
    	try{
    	ResultSet rs =db.executeQuery(sql);
    	if(rs.next())
    	{f=false;}
          }catch(Exception e){ e.getMessage();}
    	return f;   
    	}
}