Header

By: INAYAT HUSSAIN on 07:45

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Setting Header:

Benefit:

History Does not maintained into the browser thus we can't reach to the user page even after logged out BY pressing backslash or going back to the browser.

MOST common is below:

response.setHeader("Cache-Control","no-store, no-cache, must-revalidate");

response.setHeader("Pragma", "no-cache");

response.setHeader("Expires", "-1");

Setting Timeout To session:

maintain follwing in WEB.XML file:

Way 1

 time in minutes

Way 2

In Servlet:

Session.getCreationTime();

Session.getLastAccessTime();

session.setMAxInactiveInternal(time in millisecond);

Setting permanent Cookie IN Browser


index.html

LoginServlet.java

package cookies.demo;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
   
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out=response.getWriter();
Cookie c = null;
   String uname=request.getParameter("username");
   String color=request.getParameter("color");
boolean iscookie=false;

   if(uname.equals("inayat"))
   {
HttpSession session=request.getSession(true);
session.setAttribute("username", uname);

Cookie ColorArray[]=request.getCookies();

if(ColorArray!=null&&ColorArray.length>0){             ///if cookie available alreadty
for(Cookie cookie:ColorArray){
if(cookie.getName().equals("favcolor")){
iscookie=true;
break;
}
}
}

if(iscookie==true){

Cookie cookie=new Cookie("favcolor",color);     // Set if not available
cookie.setMaxAge(365*24*60*60);
   response.addCookie(cookie);
   
}
     out.println("vist your page")
        response.sendRedirect("welcome");
   



}else{
     out.println("wrong id...");
  }


}

}

Welcome.java

package cookies.demo;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;


@WebServlet("/welcome")
public class welcome extends HttpServlet {
private static final long serialVersionUID = 1L;

     
 
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

String color=null;
HttpSession session=request.getSession(false);
 String name=(String) session.getAttribute("username");
  PrintWriter out=response.getWriter();
 out.print("LoggedIn:");
 out.println(name);

Cookie[] cookies=request.getCookies();
for(Cookie cookie:cookies){
if(cookie.getName().equals("favcolor")){
color=cookie.getValue();                           //  Fetching inserted value in Cookie Value
break;
}

}


out.println(" &nbsp");
PrintWriter out1=response.getWriter();
out.println("vist your page");
}
}