How to use

generate64BitRandomLong

method

in

com.nike.wingtips.TraceAndSpanIdGenerator

/**
 * @return A newly-generated random 64-bit long encoded as a String <b>UNSIGNED AND IN HEX FORMAT</b> - intended for use as a trace or span ID.
 *          The returned string will have a length of 16 characters (zeroes will be prepended as padding if necessary to
 *          reach a string length of 16). The hex format is necessary to be fully B3 compatible and therefore fully Zipkin compatible
 *          (see <a href="http://zipkin.io/pages/instrumenting.html">http://zipkin.io/pages/instrumenting.html</a>). If you simply want a full 64-bit
 *          random normal *signed* Java long encoded in *decimal* format for other reasons then you can call {@link String#valueOf(long)} and pass in a
 *          long created by {@link #generate64BitRandomLong()}.
 *          <p>You can convert the unsigned hex-encoded longs returned by this method back into normal Java long primitives by passing them to
 *          {@link #unsignedLowerHexStringToLong(String)}.
 */
public static String generateId() {
  return longToUnsignedLowerHexString(generate64BitRandomLong());
}

@Test
public void generate64BitRandomLong_should_not_generate_duplicate_ids_over_reasonable_number_of_attempts() throws Exception {
  // given
  Set<Long> randomLongs = new HashSet<>();
  int numAttempts = 1000000;
  // when
  for (int i = 0; i < numAttempts; i++) {
    randomLongs.add(TraceAndSpanIdGenerator.generate64BitRandomLong());
  }
  // then
  assertThat(randomLongs.size()).isEqualTo(numAttempts);
}