如何在GAE / java中使用get / set cookie

Question

hi I'm trying to get all cookies of the browser, like I did in my java projects.

javax.servlet.http.Cookie    
String value = "";
    Cookie cookie;
    Cookie[] allcookies = request.getCookies();
        for(int i=0;i<allscookies.length;i++){
                cookie = allcookies[i];
                if(cookie.getDomain().equals("mydomain") && cookie.getName().equals("cookiename")){
                    value = cookie.getValue();
                }
            }

but does not work on my Google App Engine project and I get this error

HTTP ERROR 500

Caused by:

java.lang.NullPointerException

Anyone knows any other way.Also try with this library but can not find how to use it no where com.google.appengine.repackaged.org.json.Cookie

Answer 1

It's not about GAE.

Cookie[] allcookies = request.getCookies();

May be null in any environment - it depends on whether the browser sent any cookies for the URL you're calling. Presumably your browser always had some cookies for the test URL you've used before deploying to GAE, and no cookies for the GAE URL.

Simply add an if (allcookies != null) { ... } around the loop.