apollo-portal/src/main/java/com/ctrip/framework/apollo/openapi/service/ConsumerService.java/ConsumerService/generateToken
class ConsumerService:  String generateToken(String consumerAppId, Date generationTime, String
      consumerTokenSalt) {
    return Hashing.sha1().hashString(KEY_JOINER.join(consumerAppId, TIMESTAMP_FORMAT.format
        (generationTime), consumerTokenSalt), Charsets.UTF_8).toString();
  }