How to use

RandomBasedGenerator

in

com.fasterxml.uuid.impl

/**
 * Factory method for constructing UUID generator that uses specified
 * random number generator for constructing UUIDs according to standard
 * method number 4.
 */
public static RandomBasedGenerator randomBasedGenerator(Random rnd) {
  return new RandomBasedGenerator(rnd);
}

private final static long _toLong(byte[] buffer, int offset)
{
  long l1 = _toInt(buffer, offset);
  long l2 = _toInt(buffer, offset+4);
  long l = (l1 << 32) + ((l2 << 32) >>> 32);
  return l;
}

@Override
public UUID generate()
{
  /* 14-Oct-2010, tatu: Surprisingly, variant for reading byte array is
   *   tad faster for SecureRandom... so let's use that then
   */
  long r1, r2;
  if (_secureRandom) {
    final byte[] buffer = new byte[16];
    _random.nextBytes(buffer);
    r1 = _toLong(buffer, 0);
    r2 = _toLong(buffer, 1);
  } else {
    r1 = _random.nextLong();
    r2 = _random.nextLong();
  }
  return UUIDUtil.constructUUID(UUIDType.RANDOM_BASED, r1, r2);
}

  public static java.util.UUID random() {
    return uuidGenerator.generate();
  }
}

public static UUID generateRandomUUID() {
  return UUID_GENERATOR.generate();
}

public static UUID generateRandomUUID() {
  return UUID_GENERATOR.generate();
}

/**
 * Factory method for constructing UUID generator that uses specified
 * random number generator for constructing UUIDs according to standard
 * method number 4.
 */
public static RandomBasedGenerator randomBasedGenerator(Random rnd) {
  return new RandomBasedGenerator(rnd);
}

private final static long _toLong(byte[] buffer, int offset)
{
  long l1 = _toInt(buffer, offset);
  long l2 = _toInt(buffer, offset+4);
  long l = (l1 << 32) + ((l2 << 32) >>> 32);
  return l;
}

@Override
public UUID generate()
{
  /* 14-Oct-2010, tatu: Surprisingly, variant for reading byte array is
   *   tad faster for SecureRandom... so let's use that then
   */
  long r1, r2;
  if (_secureRandom) {
    final byte[] buffer = new byte[16];
    _random.nextBytes(buffer);
    r1 = _toLong(buffer, 0);
    r2 = _toLong(buffer, 1);
  } else {
    r1 = _random.nextLong();
    r2 = _random.nextLong();
  }
  return UUIDUtil.constructUUID(UUIDType.RANDOM_BASED, r1, r2);
}

/**
 * Return the next unique id for the type with the given name using the generator's id generation strategy.
 *
 * @return
 */
@Override
public long getId() {
  return generator.generate().getMostSignificantBits();
}

/**
 * Return the next unique id for the type with the given name using the generator's id generation strategy.
 *
 * @return
 */
@Override
public long getId() {
  return generator.generate().getMostSignificantBits();
}

  /**
   * Generate short version random UUID
   *
   * @return UUID
   */
  public static String shortUuid() {
    RandomBasedGenerator generator = Generators.randomBasedGenerator();
    UUID uuid = generator.generate();
    // https://gist.github.com/LeeSanghoon/5811136
    long l = ByteBuffer.wrap(uuid.toString().getBytes()).getLong();
    return Long.toString(l, Character.MAX_RADIX);
  }
}

/**
 * Create a random UUID string which does not include dashes.
 * 
 * @return
 */
public static String randomUUID() {
  final UUID uuid = UUID_GENERATOR.generate();
  return (digits(uuid.getMostSignificantBits() >> 32, 8) + digits(uuid.getMostSignificantBits() >> 16, 4)
    + digits(uuid.getMostSignificantBits(), 4) + digits(uuid.getLeastSignificantBits() >> 48, 4)
    + digits(uuid.getLeastSignificantBits(), 12));
}

/**
 * Create a random UUID string which does not include dashes.
 * 
 * @return
 */
public String randomUUID() {
  final UUID uuid = UUID_GENERATOR.generate();
  String randomUuid = (digits(uuid.getMostSignificantBits() >> 32, 8) + digits(uuid.getMostSignificantBits() >> 16, 4) + digits(uuid
    .getMostSignificantBits(), 4) + digits(uuid.getLeastSignificantBits() >> 48, 4) + digits(uuid.getLeastSignificantBits(), 12));
  return randomUuid;
}