JSP+Servlet+JavaBean+JDBC实现用户登录，及成绩查询

用Myeclipse新建web项目jsp+javabean，具体功能如下：

A.       创建与数据表相对应的javabean

B.       创建一个用户登录页面 ，输入用户名和密码；

C.       创建一个连接数据库、及数据库操作的javabean（DateDao），用来连接数据库、执行数据库操作

D.       登录页面提交时，servlet使用DateDao进行登录验证；登录成功跳转到显示登录用户成绩的页面，登录失败跳转到登录页面；

1、创建Bean

package com.Server;

import java.io.Serializable;

public class Student implements Serializable 
{
private int student_id;
private String student_name;
private int student_password;
 

public Student(String name,int password)
{
	this.student_name=name;
	this.student_password=password;
}



public void setStudent_id(int student_id) 
	{
	this.student_id = student_id;
	}
public int getStudent_id() 
	{
	return student_id;
	}



public void setStudent_name(String student_name) 
	{
	this.student_name = student_name;
	}
public String getStudent_name()
	{
	return student_name;
	}




public void setStudent_password(int student_password)
	{
	this.student_password = student_password;
	}
public int getStudent_password()
	{
	return student_password;
	}


}

2、用户登录界面JSP、显示成绩JSP

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>  
<%@ page import="com.Server.Student"%> 

















  

    
登录页面

  

    
用户名：
    

  
  

    
密码:
    

  
  
  

    

  

<%@page import="java.awt.Window"%>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>


  
  
    


  

  
  <%
  String message = "";
  String Sid = request.getParameter("Sid");
  String getjava = request.getParameter("getjava");
  String c = request.getParameter("c");
  
  System.out.println(Sid+"score页面");
  String flag = request.getParameter("flag");
  if(flag!=null&&flag.equals("success"))
  {
  	message = "登录成功！";
  }else if(flag!=null&&flag.equals("false"))
  {
  	message = "登录失败！";
  	Sid = "无";
  	getjava = "无";
  	c = "无";	 
    }
 	 %>
   
   

  
  
  
  <%=message %>

  ID:<%=Sid %>

  Java成绩：<%=getjava %>

  c++成绩：<%=c %>

  返回登陆
 
   
 
    
  
  
  
  

3、DateDao.java 连接数据库及操作

package com.Server;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DateDao
{

	
	public static Connection con = null;//定义连接
	public static Statement st = null;//定义statement
	public ResultSet result = null;//定义结果集 
	public static String driver;//定义驱动   
    public static String url;//定义URL   
    public static String user;//定义用户名   
    public static String password;//定义密码     
  
	//建立与数据库连接的函数  
	    public Connection getConn(){  
	    	try { 
	    		
		    	driver="com.mysql.jdbc.Driver";
		    	url="jdbc:mysql://localhost:3306/test2";
		    	user="root";
		    	password="";
	            
					Class.forName(driver);
				   
	            con = DriverManager.getConnection(url,user,password);//获取数据库连接
	            System.out.println("-------连接成功------");
	            }  
	    	catch (SQLException e) 
	        {
	        	e.printStackTrace();
			} 
	    	catch (ClassNotFoundException e) 
	    	{	
				e.printStackTrace();
			} 
	    	return this.con;   
	    }   
	    
	    
	public DateDao()
	{

		this.con=this.getConn();
		//构造函数，默认加裁配置文件为jdbc.driver
	}
	
	
 
	 // 执行数据库查询并返回查询结果
	 public  ResultSet query(String sql)
	 {
		 this.con=this.getConn();
		 try 	{
				st = con.createStatement();//获取Statement
				result = st.executeQuery(sql);//执行查询，返回结果集				
				 } catch (Exception e)
					 {
				e.printStackTrace();
					 }
		return result;
	 }
	 
	 
	 //执行数据库更新  
	    public void update(String sql)
	    {  
	    	this.con=this.getConn();
		 try 	{	
				st = con.createStatement();//获取Statement
				st.executeUpdate(sql);//执行查询，返回结果集				
				 } catch (Exception e)
					 {
				e.printStackTrace();
					 }
	    }  
	 

	    
	  //关闭数据库连接  
	    public void close(){  
	        try{  
	            if (result != null)result.close();  
	            if (st != null)st.close();   
	            if (con != null)con.close();  
	        }catch(Exception ex){  
	            ex.printStackTrace();  
	        }         
	    } 
	
	
}

4、Servlet调用DateDao操作数据库

package Servlet;

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

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

import com.Server.DateDao;
import com.Server.Student;

public class check_servlet extends HttpServlet {
	private static final long serialVersionUID = 1L;


	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
	{
		doPost(request, response);
	}

	
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException 
	{
		 
		 
		
		DateDao mysql = new DateDao();
		String context = request.getContextPath();
		
		
		
          
        String username = new String(request.getParameter("studentname").getBytes("iso-8859-1"),"utf-8"); 
        Integer userpassword = Integer.parseInt(request.getParameter("studentpassword"));
        
 
        System.out.println(username);
        System.out.println(userpassword);
        
       
        String sql = "select*from student where Sname='"+username+"' and Password='"+userpassword+"'";  
        
        Student student= new Student(username,userpassword);
         
     	
        	//验证登录
        	ResultSet rs = mysql.query(sql);                      
            try {
				if (rs.next()){              	
					
					//获取该成员ID
					Integer Sid = rs.getInt("Sid");
					System.out.println(Sid);
					mysql.close();//关闭连接
					
					//通过ID查询该成员成绩
					
					Integer getjava = 0;
					Integer c = 0;
						
					String scoresql = "select*from score where Sid ='"+Sid+"'";
					ResultSet rs1 = mysql.query(scoresql);
						
					if(rs1.next())
						{
						
						getjava = rs1.getInt("Java");
						System.out.println(getjava);
						
						c = rs1.getInt("c");
						System.out.println(c);
						
						mysql.close();//关闭连接
						}	
					response.sendRedirect(context+"/student_score.jsp?flag=success&Sid="+Sid+"&getjava="+getjava+"&c="+c); 
					
				}else{  
					  
					mysql.close();
					response.sendRedirect(context+"/student_score.jsp?flag=false&Sid=null"); 
     	
				}
			} catch (SQLException e) {
			
				e.printStackTrace();
			}                     
        
     
                                                                               
    
	}

}