Session Tracking

title: Session Tracking in Servlet description: User session maintain karne ke tarike

HTTP stateless hai — session tracking se user state maintain karte hain.

4 Techniques

1. HttpSession (Most Common)

java exampleWoHoTech

// Login servlet — session create
HttpSession session = request.getSession();
session.setAttribute("userId", userId);
session.setAttribute("username", username);
session.setMaxInactiveInterval(30 * 60); // 30 minutes

// Other servlets — session read
HttpSession session = request.getSession(false); // false = don't create new
if (session != null) {
    String username = (String) session.getAttribute("username");
    System.out.println("Logged in: " + username);
}

// Logout
session.invalidate(); // Session destroy

2. Cookies

java exampleWoHoTech

// Set cookie
Cookie cookie = new Cookie("userId", "12345");
cookie.setMaxAge(60 * 60 * 24); // 1 day in seconds
cookie.setPath("/"); // Available for all paths
cookie.setHttpOnly(true); // JS access nahi
response.addCookie(cookie);

// Read cookies
Cookie[] cookies = request.getCookies();
if (cookies != null) {
    for (Cookie c : cookies) {
        if ("userId".equals(c.getName()))
            System.out.println("User: " + c.getValue());
    }
}

// Delete cookie
Cookie toDelete = new Cookie("userId", "");
toDelete.setMaxAge(0);
response.addCookie(toDelete);

3. URL Rewriting

java exampleWoHoTech

String url = response.encodeURL("/profile?userId=123");
out.println("<a href='" + url + "'>Profile</a>");
// Session ID URL mein add ho jaata hai jab cookies disabled ho

4. Hidden Form Fields

Session Tracking

4 Techniques

1. HttpSession (Most Common)

2. Cookies

3. URL Rewriting

4. Hidden Form Fields

Continue learning this concept

Session Tracking

4 Techniques

1. HttpSession (Most Common)

2. Cookies

3. URL Rewriting

4. Hidden Form Fields

Continue learning this concept