code: private void initJavaClassCache(Class clazz) {
          String clazzName = clazz.getName();
          Class cl = classCache.get(clazzName);
          if (null == cl) {
              synchronized (clazz) { // 进行锁控制
                  cl = classCache.get(clazzName); // double check
                  if (cl != null) {
                      return;
                  }
                  Method[] methods = clazz.getMethods();
                  for (Method m : methods) {
                      String key = buildMethodKey(clazzName, m.getName(), m.getParameterTypes());
                      methodCache.put(key, m);
                  }
                  allMethodCache.put(clazzName, methods);
              }
          }
      }
docs: ============================ helper mthod =========================