纯JSP用户登录系统

来源：互联网发布：图文网站源码编辑：程序博客网时间：2024/04/27 19:04

login.jsp

<%@ page language="java" import="java.util.*" pageEncoding="gb2312"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'login.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">-->  </head>    <body bgcolor = "pink">    <!-- 居中对齐 -->  <center>  用户登录<br>  <hr>  <%  String flag = request.getParameter("errNo");  try{    if(flag.equals("1")){  out.println("密码错误");  }  if(flag.equals("2")){  out.println("用户名不存在");  }  }catch(Exception e){  e.printStackTrace();  }       %>  <form action = "loginCl.jsp" method="post">  用户名：<input type="text" name="username"><br>  密  码：<input type="password" name ="passwd"><br>          <input type="submit" value="提交">     <input type="reset" value="重置">      </form>  </center>  </body></html>

loginCl.jsp验证用户名密码

<%@ page language="java" import="java.util.*,java.sql.*" pageEncoding="gb2312"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'loginCl.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">-->  </head>    <body>  <%    Connection conn= null ;  Statement smt = null;  ResultSet rs = null;    try{    //接收用户名和密码  String u = request.getParameter("username");  String p = request.getParameter("passwd");    //在数据库中验证用户  String className="oracle.jdbc.driver.OracleDriver";  //String url = "jdbc:oracle:thin:@192.168.1.3:1521:unionuat";  String url = "jdbc:oracle:thin:@192.168.1.3:1521:unionuat";    String userName = "sales_jacdcs";  String userPass ="sales_jacdcs";      //加载驱动  Class.forName(className);  //得到连接  //注意这里饭的错误：url userName uerPass已经是字符串的格式。下面的语句不需要加""双引号。害了我10分钟   conn = DriverManager.getConnection(url,userName,userPass);  //创建Statement   smt = conn.createStatement();    //查询  //StringBuffer sb = "select passwd from yyytestusers where username = ';   rs = smt.executeQuery("select passwd from yyytestusers where username = '"+ u +"'");  //    if(rs.next()){  //c存在用户名  //判断密码  if(rs.getString(1).equals(p)){  response.sendRedirect("wel.jsp?user="+u);  }else{  //密码不对返回到登陆  response.sendRedirect("login.jsp?errNo=1");  }    }else{  response.sendRedirect("login.jsp?errNo=2");  }    }catch(Exception e){    e.printStackTrace();  }finally{  if(null != rs){  rs.close();  }  if(null != smt){  smt.close();  }  if(null != conn){  conn.close();  }      }          /*  //简单验证用户名密码  if(u.equals("yyy") && p.equals("123")){  //跳转页面  //将数据传到下一个界面(注意这里的wel.jsp?user中间不允许有空格，否则会出错)  response.sendRedirect("wel.jsp?user="+u);    //  }else{    //不合法  response.sendRedirect("login.jsp");  }    */       %>  </body></html>

wel.jsp成功登录界面

<%@ page language="java" import="java.util.*,  java.sql.*" pageEncoding="gb2312"%><%String path = request.getContextPath();String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <base href="<%=basePath%>">        <title>My JSP 'wel.jsp' starting page</title>    <meta http-equiv="pragma" content="no-cache"><meta http-equiv="cache-control" content="no-cache"><meta http-equiv="expires" content="0">    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"><meta http-equiv="description" content="This is my page"><!--<link rel="stylesheet" type="text/css" href="styles.css">-->  </head>    <body>  登陆成功!<%= request.getParameter("user") %><br>  <a href="login.jsp">重新登陆</a>    <h1>用户列表</h1>    <%  //定义分页用到的4个变量  int pageSize = 3; //每页显示3个  int pageNow = 1; //默认第一页  int rowCount = 0;//所有记录数  int pageCount=0;// rowCount/pageSize    //获取页面传来的pageNow信息  String pp = request.getParameter("pageTo");  if(pp != null){  try{    pageNow = Integer.parseInt(pp);    }catch(Exception e){  out.println("pagenow=" + pageNow);  e.printStackTrace();  }  }    //查询所有的记录数    Connection conn= null ;  Statement smt = null;  ResultSet rs = null;    try{    //接收用户名和密码  String u = request.getParameter("username");  String p = request.getParameter("passwd");    //在数据库中验证用户  String className="oracle.jdbc.driver.OracleDriver";  //String url = "jdbc:oracle:thin:@192.168.1.3:1521:unionuat";  String url = "jdbc:oracle:thin:@192.168.1.3:1521:unionuat";    String userName = "sales_jacdcs";  String userPass ="sales_jacdcs";      //加载驱动  Class.forName(className);  //得到连接  //注意这里饭的错误：url userName uerPass已经是字符串的格式。下面的语句不需要加""双引号。害了我10分钟   conn = DriverManager.getConnection(url,userName,userPass);  //创建Statement   smt = conn.createStatement();    //查询  //StringBuffer sb = "select passwd from yyytestusers where username = ';   rs = smt.executeQuery("select count(*) from yyytestusers ");    //一定要rs.next()  rs才指向要取得值的地方  if(rs.next()){    rowCount = rs.getInt(1);//1 ：表示 一行一列    }  }catch(Exception e){    e.printStackTrace();    }finally{  /*if(null != rs){  rs.close();  }  if(null != smt){  smt.close();  }  if(null != conn){  conn.close();  }*/  }    //计算pageCount  if(rowCount%pageSize == 0){  pageCount = rowCount / pageSize;  }else{  pageCount = rowCount/ pageSize + 1;  }  //查询需要显示的记录  String select_by_pageNow = "select * from (select rownum rn, a.* from yyytestusers a) where rn < "+ (pageNow*pageSize+1)   +"and rn not in (select rn from (select rownum rn, a.* from yyytestusers a) where rn < "+((pageNow-1)*pageSize+1) +    ") order by userid";  try{  rs = smt.executeQuery(select_by_pageNow);  }catch(Exception e){  e.printStackTrace();  }    %>  <table border = "1">  <tr><td>用户ID</td><td>名字</td><td>密码</td><td>Email</td><td>级别</td></tr>  <%  while(rs.next()){  %>  <!-- 注意：这里使用的是字符串的形式得到值 rs.getInt("userid")  rs.getInt(1) 会出异常！！待答复-->  <tr><td><%=rs.getInt("userid") %></td><td><%=rs.getString("username") %></td><td><%=rs.getString("passwd") %></td><td><%=rs.getString("email") %></td><td><%=rs.getInt("grade") %></td></tr>    <%  }   %>    </table>    <%  //显示超链接  //首页  out.println("<a href=wel.jsp?pageTo="+1+">首页</a>");  //上一页  if(pageNow != 1){  out.println("<a href=wel.jsp?pageTo="+(pageNow - 1)+">上一页</a>");  }  // 判断页数的  if(pageNow == 1){  for(int i = pageNow; i <= pageNow + 5; i++){  out.println("<a href= wel.jsp?pageTo="+i+"> ["+i+"] </a>");  }  }else if(pageNow == 2){  for(int i = pageNow-1; i < pageNow + 5; i++){  out.println("<a href= wel.jsp?pageTo="+i+"> ["+i+"] </a>");  }  }else if(pageNow == pageCount){  for(int i = pageCount-4; i <= pageCount; i++){  out.println("<a href= wel.jsp?pageTo="+i+"> ["+i+"] </a>");  }  }else if(pageNow == pageCount-1){  for(int i = pageCount-3; i <= pageCount+1; i++){  out.println("<a href= wel.jsp?pageTo="+i+"> ["+i+"] </a>");  }  }else{  for(int i=pageNow - 2; i <= pageNow + 2; i++){  out.println("<a href= wel.jsp?pageTo="+i+"> ["+i+"] </a>");  }    }    //显示写一页  if(pageNow != pageCount){  out.println("<a href=wel.jsp?pageTo="+(pageNow + 1)+">下一页</a>");  }  //末页  out.println("<a href=wel.jsp?pageTo="+pageCount+">末页</a>");             %>  </body></html>