JSP Cookies Handling
- Cookies are the text files which are stored on the client machine.
- They are used to track the information for various purposes.
- It supports HTTP cookies using servlet technology
- The cookies are set in the HTTP Header.
- If the browser is configured to store cookies, it will keep information until expiry date.
Following are the cookies methods:
- Public void setDomain(String domain)
It is used to set the domain to which the cookie applies
- Public String getDomain()
It is used to get the domain to which cookie applies
- Public void setMaxAge(int expiry)
It sets the maximum time which should apply till the cookie expires
- Public intgetMaxAge()
It returns the maximum age of cookie
- Public String getName()
It returns the name of the cookie
- Public void setValue(String value)
Sets the value associated with the cookie
- Public String getValue()
Get the value associated with the cookie
- Public void setPath(String path)
It sets the path to which cookie applies
- Public String getPath()
It gets the path to which the cookie applies
- Public void setSecure(Boolean flag)
It should be sent over encrypted connections or not.
- Public void setComment(String cmt)
It describes the cookie purpose
- Public String getComment()
It the returns the cookie comments which has been described.
Cookie Set-up using following steps:
- Creating the cookie object
- Setting the maximum age
- Sending the cookie in HTTP response headers
Example:
In this example, we are creating cookies of username and email and add age to the cookie for 10 hours and trying to get the variable names in the action_cookie.jsp
Action_cookie.jsp.
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Guru Cookie</title>
</head>
<body>
<form action="action_cookie_main.jsp" method="GET">
Username: <input type="text" name="username">
<br />
Email: <input type="text" name="email" />
<input type="submit" value="Submit" />
</form>
</body>
</html>
Action_cookie_main.jsp
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<%
Cookie username = new Cookie("username",
request.getParameter("username"));
Cookie email = new Cookie("email",
request.getParameter("email"));
username.setMaxAge(60*60*10);
email.setMaxAge(60*60*10);
// Add both the cookies in the response header.
response.addCookie( username );
response.addCookie( email );
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Guru Cookie JSP</title>
</head>
<body>
<b>Username:</b>
<%= request.getParameter("username")%>
<b>Email:</b>
<%= request.getParameter("email")%>
</body>
</html>Explanation of the code:
Action_cookie.jsp
Code Line 10-15: Here we are taking a form which has to be processed in action_cookie_main.jsp. Also, we are taking two fields "username" and "email" which has to be taken input from the user with a submit button.
Action_cookie_main.jsp
Code Line 6-9: Creating two cookie objects of "username" and "email" using request.getParameter.
Code Line 12-13: Here we are adding age to both the cookies, which have been created of 10 hours i.e. cookies will expire in that age.
Code Line 16-17: Adding cookies to the session of username and email and these two cookies can fetched when requested by getParameter().
When you execute the above code you get the following output:
Output:
When we execute the action_cookie.jsp we get two fields username and email, and it takes user input and then we click on the submit button.
We get the output from action_cookie_main.jsp where variables are stored in the cookies on the client side.
