Brief about cookies in JSP
Cookies are text files stored in client computer and are used for
tracking information and authentication purpose, JSP transparently
supports HTTP cookies sing underlying servlet technology.
This process includes following stuffs :
- Server sends a set of cookies to the client browser.
- Client browser stores and prompt to save or not.
- Next time when the client visits the same address the cookies are used to get the information of the user last saved.
Setting Cookies in JSP
Example:
JSP File (index.jsp)
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>nirajanghimireyworkshop.blogspot.com</title>
</head>
<body>
<h2> Nirajan Ghimirey's Workshop Login Form </h2>
<form action="setcookie.jsp" method="POST">
<label>Name</label><input type="text" name="full_name">
<br />
<label>Email: </label><input type="text" name="email" /><br/>
<input type="submit" value="Submit" />
</form>
</body>
</html>
JSP File (setcookie.jsp)
<%
// Create cookies for name and email.
Cookie fullname = new Cookie("full_name",
request.getParameter("full_name"));
Cookie email = new Cookie("email",
request.getParameter("email"));
// Set expiry date after 24 Hrs for both the cookies.
fullname.setMaxAge(60 * 60 * 24);
email.setMaxAge(60 * 60 * 24);
// Add both the cookies in the response header.
response.addCookie(fullname);
response.addCookie(email);
%>
<html>
<head>
<title>nirajanghimireyworkshop.blogspot.com</title>
</head>
<body>
<center>
<h1>Setting Cookies Example</h1>
</center>
<p><b>Full Name: </b>
<%= request.getParameter("full_name")%>
</p><p><b>Email: </b>
<%= request.getParameter("email")%>
</p>
</body>
</html>
Reading Cookies
Example:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>nirajanghimireyworkshop.blogspot.com</title>
</head>
<body>
<center>
<h1>Reading Cookies</h1>
</center>
<%
Cookie cookie = null;
Cookie[] cookies = null;
// Get an array of Cookies associated with this domain
cookies = request.getCookies();
if( cookies != null ){
out.println("<h2>Cookies Name and Value</h2>");
for (int i = 0; i <cookies.length; i++){
cookie = cookies[i];
out.print("Name : " + cookie.getName( ) + ", ");
out.print("Value: " + cookie.getValue( )+" <br/>");
}
}else{
out.println("<h2>No cookies founds</h2>");
}
%>
</body>
</html> JSP File (index.jsp)
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>nirajanghimireyworkshop.blogspot.com</title>
</head>
<body>
<center>
<h1>Reading Cookies</h1>
</center>
<%
Cookie cookie = null;
Cookie[] cookies = null;
// Get an array of Cookies associated with this domain
cookies = request.getCookies();
if( cookies != null ){
out.println("<h2>Cookies Name and Value</h2>");
for (int i = 0; i <cookies.length; i++){
cookie = cookies[i];
out.print("Name : " + cookie.getName( ) + ", ");
out.print("Value: " + cookie.getValue( )+" <br/>");
}
}else{
out.println("<h2>No cookies founds</h2>");
}
%>
</body>
</html>
Script for deleting cookie in JSP.
Delete Cookies
Example:
JSP File (index.jsp)
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
<title>nirajanghimireyworkshop.blogspot.com</title>
</head>
<body>
<center>
<h1>Reading Cookies</h1>
</center>
<%
Cookie cookie = null;
Cookie[] cookies = null;
// Get an array of Cookies associated with this domain
cookies = request.getCookies();
if( cookies != null ){
out.println("<h2> Cookies Name and Value</h2>");
for (int i = 0; i <cookies.length; i++){
cookie = cookies[i];
if((cookie.getName( )).compareTo("full_name") == 0 ){
cookie.setMaxAge(0);
response.addCookie(cookie);
out.print("<b>Deleted cookie: </b> " +
cookie.getName( ) + "<br/>");
}
out.print("Name : " + cookie.getName( ) + ", ");
out.print("Value: " + cookie.getValue( )+" <br/>");
}
}else{
out.println(
"<h2>No cookies founds</h2>");
}
%>
</body>
</html> 
No comments:
Post a Comment