apollo-common/src/main/java/com/ctrip/framework/apollo/common/utils/UniqueKeyGenerator.java/UniqueKeyGenerator/generate
class UniqueKeyGenerator:  public static String generate(Object... args){
    String hexIdString =
        ByteUtil.toHexString(toByteArray(Objects.hash(args), MachineUtil.getMachineIdentifier(),
                                         counter.incrementAndGet()));

    return KEY_JOINER.join(TIMESTAMP_FORMAT.format(new Date()), hexIdString);

  }