docs: @IocBean(name = "mongodbServerAddressList")
      public List<ServerAddress> getServerAddressList() {
          // 看看是不是配置了集群
          List<ServerAddress> addrs = new ArrayList<>();
          if (conf.has(PROP_HOSTS)) {
              String[] address = Strings.splitIgnoreBlank(conf.get(PROP_HOSTS));
              for (String addr : address) {
                  String[] tmp = addr.split(":");
                  addrs.add(new ServerAddress(tmp[0], Integer.parseInt(tmp[1])));
              }
          } else {
              addrs.add(new ServerAddress(conf.get(PROP_IP, ServerAddress.defaultHost()), conf.getInt(PROP_PORT, ServerAddress.defaultPort())));
          }
          return addrs;
      }