apollo-common/src/main/java/com/ctrip/framework/apollo/common/config/RefreshableConfig.java/RefreshableConfig/getArrayProperty
class RefreshableConfig:  public String[] getArrayProperty(String key, String[] defaultValue) {
    try {
      String value = getValue(key);
      return Strings.isNullOrEmpty(value) ? defaultValue : value.split(LIST_SEPARATOR);
    } catch (Throwable e) {
      Tracer.logError("Get array property failed.", e);
      return defaultValue;
    }
  }