marksvlt.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.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class MarkSvlt extends HttpServlet{
//响应get请求	
public void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {
          	
    String tea_id =req.getParameter("id"); 
    String class_id=null;
    String score=null;
    String stu_id=null;
    //获得请求提交的参数
    String action = action = req.getParameter("action");
    determine deter = null;
    //根据提交请求的参数，决定执行不同的功能    
  if ("choosestu".equalsIgnoreCase(action)) {    		
     	deter = doChoose(tea_id);
     	sendBean(req,res,deter,"/choosestu.jsp");
     	   } 
     
  if ("score".equalsIgnoreCase(action)) {    		
     	deter = doAccept2(tea_id);
     	sendBean(req,res,deter,"/score.jsp");
     	   } 
     	   
  if ("marking".equalsIgnoreCase(action)) {  
        class_id=req.getParameter("class_id");
        score=req.getParameter("score") ;
        stu_id=req.getParameter("id") ;    		
     	doMarking(req,res,stu_id,class_id,score);
        res.sendRedirect("score.jsp");      
     	   } 
     	    
     	   
  if ("public".equalsIgnoreCase(action)) {  
        tea_id=req.getParameter("id");
     	deter = doChoose(tea_id);
     	sendBean(req,res,deter,"/public.jsp");
     	   }  	   
     	   
  if ("accept".equalsIgnoreCase(action)) {  
        class_id=req.getParameter("class_id");
     	deter=doAccept(class_id);
     	sendBean(req,res,deter,"/displaystu.jsp");
     	   }
     	   
  if ("enrol".equalsIgnoreCase(action)) {  
        stu_id=req.getParameter("stu_id");
        class_id=req.getParameter("class_id");
     	deter=doEnrol(req,res,stu_id,class_id);
     	sendBean(req,res,deter,"/displaystu.jsp");
     	   }	   
     	     	      	  
    }
    
    //给出学生课程的成绩
   public void doMarking(HttpServletRequest req, HttpServletResponse res,
   String stu_id,String class_id,String score)throws ServletException, IOException{
   	int num=0;
   	int temp=0;
   	determine deter =new determine();
   	num=deter.marking(stu_id,class_id,score);
   	if(num==0) doError(req,res,"更新失败！");
   	try{
   	   temp=Integer.parseInt(score);	
   		} 
   	catch(NumberFormatException e){System.out.print(e.toString());
   	doError(req,res,"格式不对，请重输！！");
   	    }
   		if(temp>=60)
   	num=deter.addMark(stu_id,class_id);
   	if(num==0) doError(req,res,"更新失败！");	
   	}
    
    //接受学生选课
   public determine doEnrol(HttpServletRequest req, HttpServletResponse res,
   String stu_id,String class_id)throws ServletException, IOException{
     	int num=0;
   		determine deter =new determine();
   	    num= deter.enrol(stu_id,class_id);
   	    if(num==0) doError(req,res,"更新失败！");
   	    return deter;
   	}
			   
  //根据教师ID，显示对应的班级和课程信息
  public determine doChoose(String tea_id){
  	determine deter =new determine();
  	deter.getClass(tea_id);
  	return deter; 	
  	}
  	
  public determine doAccept2(String class_id){
  		determine deter = new determine();
  		deter.getStudents2(class_id);
  		return deter;  		
  		}
  //根据班级ID，得到学生的详细信息		
  public determine doAccept(String class_id){
  		determine deter = new determine();
  		deter.getStudents(class_id);
  		return deter;  		
  		}		  
    //将JavaBean对象存储到request的上下文中保存
      public void sendBean(HttpServletRequest req, HttpServletResponse res,
                       determine deter, String target)
                       throws ServletException, IOException {
    req.setAttribute("deter", deter);
    RequestDispatcher rd = getServletContext().getRequestDispatcher(target);
    rd.forward(req, res);
  }
      //错误处理
      public void doError(HttpServletRequest req,
                      HttpServletResponse res,
                      String str)
                      throws ServletException, IOException {
                      	
    req.setAttribute("problem", str);
    RequestDispatcher rd = getServletContext().getRequestDispatcher("/errorpage.jsp");
    rd.forward(req, res);
  }
    //响应post请求
      public void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

    doGet(req, res);

  }
}