Encoding

It is recommended to always use a salt before encoding numbers.

All numbers must be greater than or equal to zero!

If the exception handling feature is enabled both public API encode methods will throw a IllegalArgumentException when no numbers are passed, any number is negative or greater than the maximum number size, unless the feature to allow numbers greater than the maximum interoperability number size is not enabled. When the passed argument is null a NullPointerException will be thrown.

Natural Numbers

The public API method encode(long...) can be passed one or more numbers.

final Hashids hashids = new Hashids.Builder()
  .salt("salt and pepper")
  .build();

final String singleNumberHash = hashids.encode(123L); // Result: "Blk"
final String multipleNumberHash = hashids.encode(42L, 5L, 17L); // Result: "9dTLhR"

Hexadecimal Numbers

Hexadecimal numbers can be encoded by using the public API method encodeHex(String).

If the exception handling feature is enabled the method will throw a IllegalArgumentException when the passed hexadecimal number format is not valid.

final Hashids hashids = new Hashids.Builder()
  .salt("salt and pepper")
  .build();

final String hash = hashids.encodeHex("75bcd15"); // Result: "j2g9K4y"

If the feature to allow hexadecimal number prefixes is enabled the passed value can optionally be prefixed with 0x or 0X.

final Hashids hashids = new Hashids.Builder()
  .salt("salt and pepper")
  .features(HashidsFeature.ALLOW_HEXADECIMAL_NUMBER_PREFIX)
  .build();

// Both will be "j2g9K4y"
final String hashHexPrefixLowercase = hashids.encodeHex("0x75bcd15");
final String hashHexPrefixUppercase = hashids.encodeHex("0X75bcd15");