Question

I have an ArrayList, Whom i convert to String like

ArrayList str = (ArrayList) retrieveList.get(1);
...

makeCookie("userCredentialsCookie", str.toString(), httpServletResponce);
....

private void makeCookie(String name, String value, HttpServletResponse response) {

    Cookie cookie = new Cookie(name, value);
    cookie.setPath("/");
    response.addCookie(cookie);

} //end of makeCookie()

Now when i retrieve cookie value, i get String, but i again want to convert it into ArrayList like

private void addCookieValueToSession(HttpSession session, Cookie cookie, String attributeName) {       
    if (attributeName.equalsIgnoreCase("getusercredentials")) {

        String value = cookie.getValue();
        ArrayList userCredntialsList = (ArrayList)value;  //Need String to ArrayList 
        session.setAttribute(attributeName, userCredntialsList);
        return;
    }

    String value = cookie.getValue();
    session.setAttribute(attributeName, value);

} //end of addCookieValueToSession

How can i again convert it to ArrayList?
Thank you.

Answer 1

someList.toString() is not a proper way of serializing your data and will get you into trouble.

Since you need to store it as a String in a cookie, use JSON or XML. google-gson might be a good lib for you:

ArrayList str = (ArrayList) retrieveList.get(1);
String content = new Gson().toJson(str);
makeCookie("userCredentialsCookie", content, httpServletResponce);
//...
ArrayList userCredntialsList = new Gson().fromJson(cookie.getValue(), ArrayList.class);