protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String sessionId = request.getRequestedSessionId(); if(sessionId != null) { // do something with the session ID } }
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); String sessionId = request.getRequestedSessionId(); if(sessionId != null && !sessionId.equals(session.getId())) { // invalidate any existing session associated with the provided ID session.invalidate(); // create a new session with the provided ID session = request.getSession(true); } // continue with request processing }In this example, we use the getRequestedSessionId() method to check if the client has provided a session ID in the request. If a session ID is present and does not match the ID of the current session, we invalidate the existing session and create a new one with the provided ID. The javax.servlet.http package library provides the HttpServletRequest class and its methods.