Session Handling - JSP Tutorial

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Jsp

Topic

How is Session Handled in JSP?

Explanation

Session Handling becomes mandatory when a requested data need to be sustained for further use. Since http protocol considers every request as a new one, session handling becomes important.

Following are some of the methods to handle session.

In JSP whenever a request arises the server generates a unique Session ID which is stored in the client machine.
Cookies store the information in the client browser
URL rewriting the session information is appended to the end of the URL
Hidden form fields the sessionID is embedded to GET and POST command.

Example1:

   <html>
   <body>
   <form method = "post" action="session2.jsp">
   <font>Username<input type = "text" name = "name"></font>gt;
   </font><br><br>
   <input type = "submit" name = "submit" value = "submit" >
   </form>
   </body>
   </html>

Example2:

    <%  
    String name = request.getParameter("name");
    if((name!=null)) 
	{
	 session.setAttribute("username",name);
      }
    %>
    <a href="session3.jsp">Continue</a>

Example3:

   <html>
   <head>
     <title>Welcome to session continued Page</title>
   </head>
   <body>
     <font>Welcome</font> <%= session.getAttribute("username") %>
   </body>
   </html>

In the first example "session1.jsp" we get the username using a form. When the form is submitted it goes to the second file session2.jsp which is called using form "action" attribute. A session attribute is set here using "session.setAttribute". In the third file "session3.jsp" the same username is displayed using "session.getAttribute".

Session Handling in JSP