Useful JSP code to implement a secure Login system. You can deploy the below sample JSP code for a Complete Web Login System on any Servlet/JSP container like Tomcat
login.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<h1>Login Page</h1>
<center>
<%
if(null!=request.getAttribute("errorMsg"))
{
out.print(request.getAttribute("errorMsg"));
}
%>
<form action="Check.jsp" method="post">
<pre/> <br/>Username:<input type="text" name="username">
<br/>Password:<input type="password" name="password">
<br/><input type="submit" value="Submit">
</form>
</center>
</body>
</html>
logout.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<%
session.removeAttribute("username");
session.removeAttribute("password");
session.invalidate();
%>
<h1>You're Successfully Logged out. Redirecting you back to Login page...</h1>
<% response.sendRedirect("ping.jsp"); %>
</body>
</html>
ping.jsp
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<meta http-equiv="refresh" content="120">
<title>URL Monitor</title>
</head>
<body>
<%
if (session.getAttribute("username") == null || session.getAttribute("username").equals(""))
{
//out.print("Error : Unknown Login");
//response.setHeader("Refresh", "5;url=login.jsp");
request.setAttribute("errorMsg","Please enter your Credentials to Login");
request.getRequestDispatcher("login.jsp").forward(request, response);
//response.sendRedirect("login.jsp");
}
<a href="logout.jsp">Logout</a>
//All Stuff for Logged in user goes here
</body>
</html>
Error.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<h1>Some Error has occured,Please try again later...</h1>
<a href="/login.jsp">Click here to Go back and Login again</a>
</body>
</html>
Check.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>JSP Page</title>
</head>
<body>
<%
String username=request.getParameter("username");
String password=request.getParameter("password");
if((username.equals("test") && password.equals("test")))
{
session.setAttribute("username",username);
response.sendRedirect("ping.jsp");
}
else
response.sendRedirect("Error.jsp");
%>
</body>
</html>
Server Living 