modifydo.java

一个真实的网络选课系统,由实际需求得到的,本人实际开发出来,运用JSP+TOMCAT

package servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import log.CreateLogs;

import com.JDBConnection;

public class modifydo extends HttpServlet {
	public void doPost(HttpServletRequest req, HttpServletResponse res)
	throws ServletException, IOException {	
	        
	   String message=null; 
	   String id=null;
	   id=req.getParameter("id");
	   
	   String password=null;
	   password= req.getParameter("password");
	   String password1=null;
	   password1=req.getParameter("password1");
	   
	   String temp =getPassword(req,res,id);
	   if( password.equals(temp))
	   {
		   System.out.println("学生登陆成功");
		   
		   goo(req,res,password1.trim(),id);
	   }
	   else {
		   System.out.println("学生登陆失败");
		   message="用户名或密码有误！";
		   doError(req,res,message)	;
	 	}
	 	} 
	  
	public void goo(HttpServletRequest req, HttpServletResponse res,String password,String id)
	throws ServletException,IOException
		{
		JDBConnection db= new JDBConnection();   
		String update="update userInfo set pwd='"+password+"' where stdno= '"+id+"'";
		String message="";
		if(db.executeUpdate(update))
		{
			message="修改密码成功！";
			doSuccess(req,res,message);
			System.out.println(message);
		}
		else
		{
			message="用户名或密码修改出错，请重试！";
			doError(req,res,message)	;
			System.out.println(message);
		}
			
		}
		

	  
	     
	public String getPassword(HttpServletRequest req, HttpServletResponse res,
	                        String id)
	                        throws ServletException, IOException {
		   JDBConnection db= new JDBConnection();                  	
		   String pw="";                     	                     	
		   String sql="select pwd from userInfo where stdno='"+id+"'";
		   try{
		   ResultSet rs=db.executeQuery(sql); 	
		   if(rs.next() ){
			   				pw= rs.getString("pwd").trim();
		   				 }
		   db.closeConnection();
		   	} 
		   	catch(Exception e)
		   		{ 
		   		CreateLogs.createLog(e, "modifydo.java");
		   		System.out.print(e.toString());
		   		}   	    
		   		return pw; 
	    }
	     
	     	
	      
	public void doError(HttpServletRequest req,
	                      HttpServletResponse res,
	                      String str)
	                      throws ServletException, IOException {

					    req.setAttribute("problem", str);
					    RequestDispatcher rd = getServletContext().getRequestDispatcher("/modify.jsp");
					    rd.forward(req, res);
					    
					  }
	public void doSuccess(HttpServletRequest req,
            HttpServletResponse res,
            String str)
            throws ServletException, IOException {
		req.setAttribute("problem", str);
	    RequestDispatcher rd = getServletContext().getRequestDispatcher("/login.jsp");
	    rd.forward(req, res);
	}
}