BitcoinUtil { public static Date convertIntToDate(int dateInt) { return new Date(dateInt*1000L); } private  BitcoinUtil(); static long convertSignedIntToUnsigned(int signedInt); static byte[] convertIntToByteArray(int intToConvert); static byte[] convertLongToByteArray(long longToConvert); static byte[] convertBigIntegerToByteArray(BigInteger bigIntegerToConvert,int exactArraySize); static byte[] convertVarIntByteBufferToByteArray(ByteBuffer byteBuffer); static long convertVarIntByteBufferToLong(ByteBuffer byteBuffer); static BigInteger getVarIntBI(byte[] varInt); static long getVarInt(byte[] varInt); static byte getVarIntSize(byte firstByteVarInt); static long getSize(byte[] byteSize); static byte[] reverseByteArray(byte[] inputByteArray); static byte[] convertHexStringToByteArray(String hexString); static String convertByteArrayToHexString(byte[] byteArray); static Date convertIntToDate(int dateInt); static boolean compareMagics(byte[] magic1,byte[] magic2); static byte[] getTransactionHash(BitcoinTransaction transaction); static byte[] getTransactionHashSegwit(BitcoinTransaction transaction);  }
@Test public void convertIntToDate() { int genesisBlockTimeStamp=1231006505; Date genesisBlockDate = BitcoinUtil.convertIntToDate(genesisBlockTimeStamp); SimpleDateFormat simpleFormat = new SimpleDateFormat("yyyy-MM-dd"); String genesisBlockDateString = simpleFormat.format(genesisBlockDate); String expectedDate="2009-01-03"; assertEquals( expectedDate, genesisBlockDateString,"1231006505 is equivalent to the Date 2009-01-03"); }