code: public static void blockUntilReady() {
          Set<String> notReady = new HashSet<String>() {{
              addAll(EnvUtil.getDependencies());
          }};
          while (!notReady.isEmpty()) {
              LOG.info("等待被依赖组件'" + notReady + "'...");
              try {
                  Thread.sleep(1000);
              } catch (InterruptedException e1) {
                  LOG.error(e1);
              }
              for (String dependentApplication : EnvUtil.getDependencies()) {
                  LOG.debug("这里每次均检查所有被依赖节点，而不是检查notReady集合");
                  try {
                      ApplicationRouter.singleton.allInstances(dependentApplication);
                      notReady.remove(dependentApplication);
                  } catch (ApplicationOfflineException | ApplicationUndefinedException e) {
                      LOG.info("受依赖组件未启动：" + dependentApplication);
                  }
              }
          }
      }
docs: 阻塞直到受依赖的组件在本地注册后才可以继续