Set and get session attributes syntax in servlets and java script?

Answer 1

Setting and getting session attributes is fairly easy. It is the same in both Servlets and JSPs with one exception. In a JSP, you already have access to the session object, and you do not have to declare it. In a Servlet, you must get the session like this: javax.servlet.http.HttpSession session = request.getSession(); Once you have done that, you can set a session object like this: session.setAttribute("name","value"); To retrieve the value, do this: String foo = (String) session.getAttribute("name"); A couple of things to keep in mind: * The second parameter in the setAttribute method is an Object, not a String. When you retrieve the value, you have to cast it. In the example above, I am casting it to a String. * If you try to perform a getAttribute on a session attribute that does not exist, or was not set, it will return a null. * Session attributes are not available using JavaScript. You can not set or get an attribute in JavaScript. * You do NOT need to do the 'session = request.getSession() in a JSP. It is only necessary in a Servlet.

Answer 2

In servlets, to set a session attribute, you can use request.getSession().setAttribute("attributeName", attributeValue);. To get a session attribute, you can use request.getSession().getAttribute("attributeName");.

In JavaScript, you can set a session attribute using sessionStorage.setItem("attributeName", attributeValue);. To get a session attribute, you can use sessionStorage.getItem("attributeName");. Note that sessionStorage is limited to the current tab or window, and the data persists until the tab or window is closed.