JSP实现简单的用户登录和注册

2.mysql数据库的创建

create database Duser; use Duser; create table user( name varchar(30) not null, password varchar(30) not null, constraint primary key(name) //添加姓名为主键 ); 

4.login.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>


   
    
    
  
  
  
  
  
   
    
   
用户登录页面
 
   
 
    
 
     
 
      
 
       
用户名:
 
       
 
      
 
      
 
       
密  码:
 
       
 
      
 
      
 
       
 
       
 
      
 
     
 
    
 
    
注册用户
 
   
 
  

5.registered.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>


   
    
    
  
  
  
  
  
   
    
   
新用户注册
 
   
 
    
 
     
 
      
 
       
请输入用户名:
 
       
 
      
 
      
 
       
请输入密码:
 
       
 
      
 
      
 
       
请输入确认密码:
 
       
 
      
 
     
 
    
 
       
   
 
  

6.registeredSucceed.jsp

<%@page import="java.sql.*"%>
<%@page import="javax.sql.*"%>
<%@page import="javax.naming.*"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
    <%request.setCharacterEncoding("utf-8"); %>


   
    
    
  
  
  
  
  
   
    <% Context ctx = null; DataSource ds = null; Statement stmt =null; ResultSet rs = null; Connection con = null; String name=request.getParameter("name").trim();//去除首尾空格 String password=request.getParameter("password").trim(); String refill=request.getParameter("refill").trim(); try{ ctx = new InitialContext(); ds = (DataSource)ctx.lookup("java:comp/env/jdbc/mysql");//mysql是在创建连接池时自己创建的名字 con = ds.getConnection(); stmt = con.createStatement(); if(name!=null ){ rs=stmt.executeQuery("select * from user where name='"+name+"'"); if(rs.next()){ out.print("用户已经存在 "+"请 
   注册"); }else{ if(password.equals(refill)){ stmt.executeUpdate("insert into user values('"+name+"','"+ password + "');"); %> 注册成功！！！ 
   
 三秒钟后自动转到登录页面！！！
 如果没有跳转，请点击这里！！！  
       
       <% }else{ out.print("密码输入不一致!!!
"+"重新注册"); } } }else { out.print("姓名不能为空"); } }catch(Exception e){ out.print(e); }finally{ if(rs!=null) rs.close(); if(stmt!=null) stmt.close(); if(con!=null) con.close(); } %> 


 





 
  

7.success.jsp

<%@page import="java.sql.*"%>
<%@page import="javax.sql.*"%>
<%@page import="javax.naming.*"%>
<%request.setCharacterEncoding("utf-8"); %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>


   
    
    
  
  
  
  
  
   
    <% Context ctx = null; DataSource ds = null; Statement stmt =null; ResultSet rs = null; Connection con = null; String name = request.getParameter("name").trim(); String password = request.getParameter("password").trim(); try{ ctx = new InitialContext(); ds = (DataSource)ctx.lookup("java:comp/env/jdbc/mysql");//mysql是在创建连接池时自己创建的名字 语句功能找到配置的数据库 con = ds.getConnection();//创建数据库连接 stmt = con.createStatement(); rs=stmt.executeQuery("select * from user where name='"+name+"'"); if(rs.next()){ rs=stmt.executeQuery("select * from user where name='"+name+"' and password='"+password+"'"); if(rs.next()){ out.print(name+"登录成功"); }else{ out.print("密码输入错误！！！ 
   
"+"重新登录"); } }else{ out.print(""+name+"用户不存在！！！
"+"请点击注册"); } }catch(Exception e){ out.print(e); }finally{ if(rs!=null) rs.close(); if(stmt!=null) stmt.close(); if(con!=null) con.close(); } %> 

 



 
  

另外还有登录时密码不正确的提示，以及注册时密码输入不一致的判断的功能，也可以去除注册时的空格。可以自己尝试一下这里就不做介绍了