if循环是否适用于Android中的OnpostExecute

Question

所以我转换了一个JSOn对象并将值与某些东西进行了比较，即使该值与字符串中的值相匹配，也没有调用循环，这就是我所写的内容 任何帮助将不胜感激

@Override
        protected void onPostExecute(String s) {

            JSONObject obj = null;
            try {
                obj = new JSONObject(s);
                String error_desc = obj.getString("error_desc");
                writeToFile("responseONP="+error_desc);
                if(error_desc == "Invalid Credentials") {
                    Context context = getApplicationContext();
                    CharSequence text = error_desc;
                    int duration = Toast.LENGTH_SHORT;

                    Toast toast = Toast.makeText(context, text, duration);
                    toast.show();
                }

                else{
                     Intent intent = new Intent(getBaseContext(), HomepageNormal.class);
                     startActivity(intent);
                }

            } catch (JSONException e) {
                e.printStackTrace();
            }