![Remember Me
submit
Cookies cookies[] =request.getCookies();
out.println( c[ 0 ].getName() + “ = “ + c[ 0].getValue());
out.println( c[ 1 ].getName() + “ = “ + c[ 1 ].getValue());
request
user=tom
pass=tom
0 1
user=tom pass=tom](https://image.slidesharecdn.com/session-180728194941/85/Java-Session-34-320.jpg)
Java Session
- 2. Page 2Classification: Restricted Agenda • HTTP Protocol • HttpSession API • Destroying the session of webapp • Cookies • Session Management using Cookie • Url Rewriting
- 3. Page 3Classification: Restricted Http Protocol • Http is a stateless protocol • Each request is considered as new request by the server • Protocol does not remember the conversational state
- 4. NEW NEW
- 7. Page 7Classification: Restricted HttpSession • Identify the clients using HttpSession • Information about client is stored in session object
- 8. req HttpSession HttpSession session = request.getSession()
- 9. req res
- 10. req res
- 11. service service
- 12. reqsession req.getSession() HttpSession session = req.getSession();
- 13. reqsession req.getSession() HttpSession session = req.getSession(); session.setAttribute(“home”,Home ); session.setAttribute(“home”,Home);
- 14. req user=Tomsession req.getSession() HttpSession session = req.getSession(); session.setAttribute(“user”,Tom); session.setAttribute(“user”,Tom);
- 15. req user=Tomsession req.getSession() HttpSession session = req.getSession(); String user = (String)session.getAttribute(“user”); session.getAttribute(“user”);
- 16. req user=Tomsession req.getSession() HttpSession session = req.getSession(); session.removeAttribute(“user”); session.removeAttribute(“user”,Tom);
- 17. req user=Tomsession req.getSession() HttpSession session = req.getSession(); session.removeAttribute(“user”); session.invalidate(); session.invalidate()
- 20. Page 20Classification: Restricted Destroying the session of webapp
- 21. user/pwd in invalid ${requestScope.error} submit class LoginServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) { if( user.equals(“tom”) && pwd.equals(“hr”)) { HttpSession session = request.getSession(true); session.setAttribute(“username”, user); response.sendRedirect(“Home.jsp”); } else { RequestDispatcher rd= request.getRequestDispatcher(“Login.jsp”); request.setAttribute(“error”, “user/pwd is invalid”); rd.forward( request, response ); } } } Hi John, ${sessionScope.user} Home About session user=tom Home.jsp
- 22. user/pwd in invalid ${requestScope.error} submit class LogoutServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) { HttpSession session = request.getSession(false); session.removeAttribute(“username”); session.invalidate(); } } Hi John, ${sessionScope.user} Home About session user=tom Home.jsp
- 23. Page 23Classification: Restricted HttpSession • Is accessible to all the web components through out the session.
- 24. response.sendRedirect() Vs rd.forward(req, res); rd.foward(req,res) response.sendRedirect();
- 25. Page 25Classification: Restricted Cookies • Cookies allow webserver to store information on client machine • cookies are sent in response from web server • cookies are stored in partition assigned to webserver domain • All cookies for the webserver are sent on every request to the webserver
- 26. Page 26Classification: Restricted Cookies • cookies have a lifespan and are flushed by the browser at the end of lifespan -cookies are flushed when the browser exits, if the lifespan is not configured
- 28. Session Management using Cookie
- 29. Page 29Classification: Restricted Session Management using Cookie
- 30. Page 30Classification: Restricted Session Management using Cookie • Storing Cookie • Retrieving Cooking
- 31. Page 31Classification: Restricted Typical Uses of Cookies • – Identifying a user during an e-commerce session • – Avoiding username and password • – Focusing advertising • – Customizing a site
- 32. Remember Me submit if ( rememberMe) { Cookie c = new Cookie(“user”, username); response.addCookie( c ) ; Cookie c2 = new Cookie(“pass”, pass); response.addCookie( c2 ) } user=tom pass=tom
- 33. Remember Me submit if ( rememberMe) { Cookie c = new Cookie(“user”, username); response.addCookie( c ) ; Cookie c2 = new Cookie(“pass”, pass); response.addCookie( c2 ) } user=tom pass=tom
- 34. Remember Me submit Cookies cookies[] =request.getCookies(); out.println( c[ 0 ].getName() + “ = “ + c[ 0].getValue()); out.println( c[ 1 ].getName() + “ = “ + c[ 1 ].getValue()); request user=tom pass=tom 0 1 user=tom pass=tom
- 35. Page 35Classification: Restricted Url Rewriting String url = response.encodeURL(“fact.do”);