Hex { public static String u8(long v) { char[] result = new char[16]; for (int i = 0; i < 16; i++) { result[15 - i] = Character.forDigit((int) v & 0x0f, 16); v >>= 4; } return new String(result); } private  Hex(); static String u8(long v); static String u4(int v); static String u3(int v); static String u2(int v); static String u2or4(int v); static String u1(int v); static String uNibble(int v); static String s8(long v); static String s4(int v); static String s2(int v); static String s1(int v); static String dump(byte[] arr, int offset, int length,
                              int outOffset, int bpl, int addressLength);  }
@Test public void testU8() { Assert.assertEquals("0000000000000000", Hex.u8(0L)); Assert.assertEquals("0000016b5086c128", Hex.u8(1560424137000L)); Assert.assertEquals("000462d53c8abac0", Hex.u8(1234567890123456L)); }