--- /dev/null
+package org.argeo.api.uuid;
+
+import java.util.Objects;
+import java.util.UUID;
+
+/** Static utilities around conversion of {@link UUID} from/to bytes. */
+public class UuidBinaryUtils {
+ /**
+ * Singleton constructor, should only be extended to provide additional static
+ * utilities.
+ */
+ protected UuidBinaryUtils() {
+ }
+
+ /**
+ * Convert bytes to an UUID, starting to read the array at this offset.
+ */
+ public static UUID fromBytes(byte[] data, int offset) {
+ Objects.requireNonNull(data, "Byte array cannot be null");
+ long msb = 0;
+ long lsb = 0;
+ for (int i = offset; i < 8 + offset; i++)
+ msb = (msb << 8) | (data[i] & 0xff);
+ for (int i = 8 + offset; i < 16 + offset; i++)
+ lsb = (lsb << 8) | (data[i] & 0xff);
+ return new UUID(msb, lsb);
+ }
+
+ /*
+ * UTILITIES
+ */
+ /**
+ * Convert bytes to an UUID. Byte array must not be null and be exactly of
+ * length 16.
+ */
+ public static UUID fromBytes(byte[] data) {
+ Objects.requireNonNull(data, "Byte array must not be null");
+ if (data.length != 16)
+ throw new IllegalArgumentException("Byte array as length " + data.length);
+ return fromBytes(data, 0);
+ }
+
+ @Deprecated
+ protected static long longFromBytes(byte[] data) {
+ long msb = 0;
+ for (int i = 0; i < data.length; i++)
+ msb = (msb << 8) | (data[i] & 0xff);
+ return msb;
+ }
+
+ /** Convert this UUID to a byte array of length 16. */
+ public static byte[] toBytes(UUID uuid) {
+ Objects.requireNonNull(uuid, "UUID cannot be null");
+ long msb = uuid.getMostSignificantBits();
+ long lsb = uuid.getLeastSignificantBits();
+ return toBytes(msb, lsb);
+ }
+
+ /** Copies this {@link UUID} as bytes, using 16 bytes. */
+ public static void copyBytes(UUID uuid, byte[] arr, int offset) {
+ Objects.requireNonNull(uuid, "UUID cannot be null");
+ long msb = uuid.getMostSignificantBits();
+ long lsb = uuid.getLeastSignificantBits();
+ copyBytes(msb, lsb, arr, offset);
+ }
+
+ /** Convert two longs to a byte array with length 16. */
+ protected static byte[] toBytes(long long1, long long2) {
+ byte[] result = new byte[16];
+ for (int i = 0; i < 8; i++)
+ result[i] = (byte) ((long1 >> ((7 - i) * 8)) & 0xff);
+ for (int i = 8; i < 16; i++)
+ result[i] = (byte) ((long2 >> ((15 - i) * 8)) & 0xff);
+ return result;
+ }
+
+ /** Copy these two longs to this byte array, using 16 bytes. */
+ protected static void copyBytes(long long1, long long2, byte[] arr, int offset) {
+ assert arr.length >= 16 + offset;
+ for (int i = offset; i < 8 + offset; i++)
+ arr[i] = (byte) ((long1 >> ((7 - i) * 8)) & 0xff);
+ for (int i = 8 + offset; i < 16 + offset; i++)
+ arr[i] = (byte) ((long2 >> ((15 - i) * 8)) & 0xff);
+ }
+
+ final protected static char[] hexArray = "0123456789abcdef".toCharArray();
+
+ /** Converts a byte array to an hex String. */
+ public static String toHexString(byte[] bytes) {
+ char[] hexChars = new char[bytes.length * 2];
+ for (int j = 0; j < bytes.length; j++) {
+ int v = bytes[j] & 0xFF;
+ hexChars[j * 2] = hexArray[v >>> 4];
+ hexChars[j * 2 + 1] = hexArray[v & 0x0F];
+ }
+ return new String(hexChars);
+ }
+
+ /*
+ * COMPACT STRING
+ */
+
+ /** To a 32 characters hex string without '-'. */
+ public static String toCompact(UUID uuid) {
+ return toHexString(toBytes(uuid));
+ }
+
+ /**
+ * Converts an UUID hex representation without '-' to an {@link UUID}.
+ */
+ public static UUID fromCompact(String compact) {
+ return UUID.fromString(UuidBinaryUtils.compactToStd(compact));
+ }
+
+ /**
+ * Converts an UUID hex representation without '-' to the standard form (with
+ * '-').
+ */
+ public static String compactToStd(String compact) {
+ if (compact.length() != 32)
+ throw new IllegalArgumentException(
+ "Compact UUID '" + compact + "' has length " + compact.length() + " and not 32.");
+ StringBuilder sb = new StringBuilder(36);
+ for (int i = 0; i < 32; i++) {
+ if (i == 8 || i == 12 || i == 16 || i == 20)
+ sb.append('-');
+ sb.append(compact.charAt(i));
+ }
+ String std = sb.toString();
+ assert std.length() == 36;
+ assert UUID.fromString(std).toString().equals(std);
+ return std;
+ }
+
+ /**
+ * Converts an UUID to a binary string (list of 0 and 1), with a separator to
+ * make it more readable.
+ */
+ public static String toBinaryString(UUID uuid, int charsPerSegment, char separator) {
+ Objects.requireNonNull(uuid, "UUID cannot be null");
+ String binaryString = UuidBinaryUtils.toBinaryString(uuid);
+ StringBuilder sb = new StringBuilder(128 + (128 / charsPerSegment));
+ for (int i = 0; i < binaryString.length(); i++) {
+ if (i != 0 && i % charsPerSegment == 0)
+ sb.append(separator);
+ sb.append(binaryString.charAt(i));
+ }
+ return sb.toString();
+ }
+
+ /** Converts an UUID to a binary string (list of 0 and 1). */
+ public static String toBinaryString(UUID uuid) {
+ Objects.requireNonNull(uuid, "UUID cannot be null");
+ String most = zeroTo64Chars(Long.toBinaryString(uuid.getMostSignificantBits()));
+ String least = zeroTo64Chars(Long.toBinaryString(uuid.getLeastSignificantBits()));
+ String binaryString = most + least;
+ assert binaryString.length() == 128;
+ return binaryString;
+ }
+
+ /*
+ * LOW-LEVEL UTILITIES
+ */
+ protected static String zeroTo64Chars(String str) {
+ assert str.length() <= 64;
+ if (str.length() < 64) {
+ StringBuilder sb = new StringBuilder(64);
+ for (int i = 0; i < 64 - str.length(); i++)
+ sb.append('0');
+ sb.append(str);
+ return sb.toString();
+ } else
+ return str;
+ }
+
+}