static Map getDeclaredFields_cache = newDangerousWeakHashMap(); static Field[] getDeclaredFields_cached(Class c) { Field[] fields; synchronized(getDeclaredFields_cache) { fields = getDeclaredFields_cache.get(c); if (fields == null) { getDeclaredFields_cache.put(c, fields = c.getDeclaredFields()); for (Field f : fields) makeAccessible(f); } } ret fields; }