Session tracking in J2EE

In java we can do session tracking in the following way.
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1)Cookies
2)Hidden Form Field
3)URL Rewriting
4)HttpSession

Cookies

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There are 2 types of cookies in java servlets.

1) Non-persistent cookie

2) Persistent cookie

Non-persistent cookie

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It is valid for single session only. It is removed each time when user closes the browser.

Persistent cookie

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It is valid for multiple session . It is not removed each time when user closes the 

browser. It is removed only if user logout or signout.

Cookies

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creating the cookies

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Cookie ck=new Cookie("user","sandeep_mishra");   //creating cookie  object

response.addCookie(ck);    //adding cookie in the response

deleting a cookie
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Cookie ck=new Cookie("user",""); --deleting the cookie
ck.setMaxAge(0);  //change the max age to 0
response.addCookie(ck);