--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.base/share/classes/java/util/UUID.java Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,463 @@
+/*
+ * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package java.util;
+
+import java.security.*;
+
+import sun.misc.JavaLangAccess;
+import sun.misc.SharedSecrets;
+
+/**
+ * A class that represents an immutable universally unique identifier (UUID).
+ * A UUID represents a 128-bit value.
+ *
+ * <p> There exist different variants of these global identifiers. The methods
+ * of this class are for manipulating the Leach-Salz variant, although the
+ * constructors allow the creation of any variant of UUID (described below).
+ *
+ * <p> The layout of a variant 2 (Leach-Salz) UUID is as follows:
+ *
+ * The most significant long consists of the following unsigned fields:
+ * <pre>
+ * 0xFFFFFFFF00000000 time_low
+ * 0x00000000FFFF0000 time_mid
+ * 0x000000000000F000 version
+ * 0x0000000000000FFF time_hi
+ * </pre>
+ * The least significant long consists of the following unsigned fields:
+ * <pre>
+ * 0xC000000000000000 variant
+ * 0x3FFF000000000000 clock_seq
+ * 0x0000FFFFFFFFFFFF node
+ * </pre>
+ *
+ * <p> The variant field contains a value which identifies the layout of the
+ * {@code UUID}. The bit layout described above is valid only for a {@code
+ * UUID} with a variant value of 2, which indicates the Leach-Salz variant.
+ *
+ * <p> The version field holds a value that describes the type of this {@code
+ * UUID}. There are four different basic types of UUIDs: time-based, DCE
+ * security, name-based, and randomly generated UUIDs. These types have a
+ * version value of 1, 2, 3 and 4, respectively.
+ *
+ * <p> For more information including algorithms used to create {@code UUID}s,
+ * see <a href="http://www.ietf.org/rfc/rfc4122.txt"> <i>RFC 4122: A
+ * Universally Unique IDentifier (UUID) URN Namespace</i></a>, section 4.2
+ * "Algorithms for Creating a Time-Based UUID".
+ *
+ * @since 1.5
+ */
+public final class UUID implements java.io.Serializable, Comparable<UUID> {
+
+ /**
+ * Explicit serialVersionUID for interoperability.
+ */
+ private static final long serialVersionUID = -4856846361193249489L;
+
+ /*
+ * The most significant 64 bits of this UUID.
+ *
+ * @serial
+ */
+ private final long mostSigBits;
+
+ /*
+ * The least significant 64 bits of this UUID.
+ *
+ * @serial
+ */
+ private final long leastSigBits;
+
+ private static final JavaLangAccess jla = SharedSecrets.getJavaLangAccess();
+
+ /*
+ * The random number generator used by this class to create random
+ * based UUIDs. In a holder class to defer initialization until needed.
+ */
+ private static class Holder {
+ static final SecureRandom numberGenerator = new SecureRandom();
+ }
+
+ // Constructors and Factories
+
+ /*
+ * Private constructor which uses a byte array to construct the new UUID.
+ */
+ private UUID(byte[] data) {
+ long msb = 0;
+ long lsb = 0;
+ assert data.length == 16 : "data must be 16 bytes in length";
+ for (int i=0; i<8; i++)
+ msb = (msb << 8) | (data[i] & 0xff);
+ for (int i=8; i<16; i++)
+ lsb = (lsb << 8) | (data[i] & 0xff);
+ this.mostSigBits = msb;
+ this.leastSigBits = lsb;
+ }
+
+ /**
+ * Constructs a new {@code UUID} using the specified data. {@code
+ * mostSigBits} is used for the most significant 64 bits of the {@code
+ * UUID} and {@code leastSigBits} becomes the least significant 64 bits of
+ * the {@code UUID}.
+ *
+ * @param mostSigBits
+ * The most significant bits of the {@code UUID}
+ *
+ * @param leastSigBits
+ * The least significant bits of the {@code UUID}
+ */
+ public UUID(long mostSigBits, long leastSigBits) {
+ this.mostSigBits = mostSigBits;
+ this.leastSigBits = leastSigBits;
+ }
+
+ /**
+ * Static factory to retrieve a type 4 (pseudo randomly generated) UUID.
+ *
+ * The {@code UUID} is generated using a cryptographically strong pseudo
+ * random number generator.
+ *
+ * @return A randomly generated {@code UUID}
+ */
+ public static UUID randomUUID() {
+ SecureRandom ng = Holder.numberGenerator;
+
+ byte[] randomBytes = new byte[16];
+ ng.nextBytes(randomBytes);
+ randomBytes[6] &= 0x0f; /* clear version */
+ randomBytes[6] |= 0x40; /* set to version 4 */
+ randomBytes[8] &= 0x3f; /* clear variant */
+ randomBytes[8] |= 0x80; /* set to IETF variant */
+ return new UUID(randomBytes);
+ }
+
+ /**
+ * Static factory to retrieve a type 3 (name based) {@code UUID} based on
+ * the specified byte array.
+ *
+ * @param name
+ * A byte array to be used to construct a {@code UUID}
+ *
+ * @return A {@code UUID} generated from the specified array
+ */
+ public static UUID nameUUIDFromBytes(byte[] name) {
+ MessageDigest md;
+ try {
+ md = MessageDigest.getInstance("MD5");
+ } catch (NoSuchAlgorithmException nsae) {
+ throw new InternalError("MD5 not supported", nsae);
+ }
+ byte[] md5Bytes = md.digest(name);
+ md5Bytes[6] &= 0x0f; /* clear version */
+ md5Bytes[6] |= 0x30; /* set to version 3 */
+ md5Bytes[8] &= 0x3f; /* clear variant */
+ md5Bytes[8] |= 0x80; /* set to IETF variant */
+ return new UUID(md5Bytes);
+ }
+
+ /**
+ * Creates a {@code UUID} from the string standard representation as
+ * described in the {@link #toString} method.
+ *
+ * @param name
+ * A string that specifies a {@code UUID}
+ *
+ * @return A {@code UUID} with the specified value
+ *
+ * @throws IllegalArgumentException
+ * If name does not conform to the string representation as
+ * described in {@link #toString}
+ *
+ */
+ public static UUID fromString(String name) {
+ if (name.length() > 36) {
+ throw new IllegalArgumentException("UUID string too large");
+ }
+
+ int dash1 = name.indexOf('-', 0);
+ int dash2 = name.indexOf('-', dash1 + 1);
+ int dash3 = name.indexOf('-', dash2 + 1);
+ int dash4 = name.indexOf('-', dash3 + 1);
+ int dash5 = name.indexOf('-', dash4 + 1);
+
+ // For any valid input, dash1 through dash4 will be positive and dash5
+ // negative, but it's enough to check dash4 and dash5:
+ // - if dash1 is -1, dash4 will be -1
+ // - if dash1 is positive but dash2 is -1, dash4 will be -1
+ // - if dash1 and dash2 is positive, dash3 will be -1, dash4 will be
+ // positive, but so will dash5
+ if (dash4 < 0 || dash5 >= 0) {
+ throw new IllegalArgumentException("Invalid UUID string: " + name);
+ }
+
+ long mostSigBits = Long.parseLong(name, 16, 0, dash1) & 0xffffffffL;
+ mostSigBits <<= 16;
+ mostSigBits |= Long.parseLong(name, 16, dash1 + 1, dash2) & 0xffffL;
+ mostSigBits <<= 16;
+ mostSigBits |= Long.parseLong(name, 16, dash2 + 1, dash3) & 0xffffL;
+
+ long leastSigBits = Long.parseLong(name, 16, dash3 + 1, dash4) & 0xffffL;
+ leastSigBits <<= 48;
+ leastSigBits |= Long.parseLong(name, 16, dash4 + 1) & 0xffffffffffffL;
+
+ return new UUID(mostSigBits, leastSigBits);
+ }
+
+ // Field Accessor Methods
+
+ /**
+ * Returns the least significant 64 bits of this UUID's 128 bit value.
+ *
+ * @return The least significant 64 bits of this UUID's 128 bit value
+ */
+ public long getLeastSignificantBits() {
+ return leastSigBits;
+ }
+
+ /**
+ * Returns the most significant 64 bits of this UUID's 128 bit value.
+ *
+ * @return The most significant 64 bits of this UUID's 128 bit value
+ */
+ public long getMostSignificantBits() {
+ return mostSigBits;
+ }
+
+ /**
+ * The version number associated with this {@code UUID}. The version
+ * number describes how this {@code UUID} was generated.
+ *
+ * The version number has the following meaning:
+ * <ul>
+ * <li>1 Time-based UUID
+ * <li>2 DCE security UUID
+ * <li>3 Name-based UUID
+ * <li>4 Randomly generated UUID
+ * </ul>
+ *
+ * @return The version number of this {@code UUID}
+ */
+ public int version() {
+ // Version is bits masked by 0x000000000000F000 in MS long
+ return (int)((mostSigBits >> 12) & 0x0f);
+ }
+
+ /**
+ * The variant number associated with this {@code UUID}. The variant
+ * number describes the layout of the {@code UUID}.
+ *
+ * The variant number has the following meaning:
+ * <ul>
+ * <li>0 Reserved for NCS backward compatibility
+ * <li>2 <a href="http://www.ietf.org/rfc/rfc4122.txt">IETF RFC 4122</a>
+ * (Leach-Salz), used by this class
+ * <li>6 Reserved, Microsoft Corporation backward compatibility
+ * <li>7 Reserved for future definition
+ * </ul>
+ *
+ * @return The variant number of this {@code UUID}
+ */
+ public int variant() {
+ // This field is composed of a varying number of bits.
+ // 0 - - Reserved for NCS backward compatibility
+ // 1 0 - The IETF aka Leach-Salz variant (used by this class)
+ // 1 1 0 Reserved, Microsoft backward compatibility
+ // 1 1 1 Reserved for future definition.
+ return (int) ((leastSigBits >>> (64 - (leastSigBits >>> 62)))
+ & (leastSigBits >> 63));
+ }
+
+ /**
+ * The timestamp value associated with this UUID.
+ *
+ * <p> The 60 bit timestamp value is constructed from the time_low,
+ * time_mid, and time_hi fields of this {@code UUID}. The resulting
+ * timestamp is measured in 100-nanosecond units since midnight,
+ * October 15, 1582 UTC.
+ *
+ * <p> The timestamp value is only meaningful in a time-based UUID, which
+ * has version type 1. If this {@code UUID} is not a time-based UUID then
+ * this method throws UnsupportedOperationException.
+ *
+ * @throws UnsupportedOperationException
+ * If this UUID is not a version 1 UUID
+ * @return The timestamp of this {@code UUID}.
+ */
+ public long timestamp() {
+ if (version() != 1) {
+ throw new UnsupportedOperationException("Not a time-based UUID");
+ }
+
+ return (mostSigBits & 0x0FFFL) << 48
+ | ((mostSigBits >> 16) & 0x0FFFFL) << 32
+ | mostSigBits >>> 32;
+ }
+
+ /**
+ * The clock sequence value associated with this UUID.
+ *
+ * <p> The 14 bit clock sequence value is constructed from the clock
+ * sequence field of this UUID. The clock sequence field is used to
+ * guarantee temporal uniqueness in a time-based UUID.
+ *
+ * <p> The {@code clockSequence} value is only meaningful in a time-based
+ * UUID, which has version type 1. If this UUID is not a time-based UUID
+ * then this method throws UnsupportedOperationException.
+ *
+ * @return The clock sequence of this {@code UUID}
+ *
+ * @throws UnsupportedOperationException
+ * If this UUID is not a version 1 UUID
+ */
+ public int clockSequence() {
+ if (version() != 1) {
+ throw new UnsupportedOperationException("Not a time-based UUID");
+ }
+
+ return (int)((leastSigBits & 0x3FFF000000000000L) >>> 48);
+ }
+
+ /**
+ * The node value associated with this UUID.
+ *
+ * <p> The 48 bit node value is constructed from the node field of this
+ * UUID. This field is intended to hold the IEEE 802 address of the machine
+ * that generated this UUID to guarantee spatial uniqueness.
+ *
+ * <p> The node value is only meaningful in a time-based UUID, which has
+ * version type 1. If this UUID is not a time-based UUID then this method
+ * throws UnsupportedOperationException.
+ *
+ * @return The node value of this {@code UUID}
+ *
+ * @throws UnsupportedOperationException
+ * If this UUID is not a version 1 UUID
+ */
+ public long node() {
+ if (version() != 1) {
+ throw new UnsupportedOperationException("Not a time-based UUID");
+ }
+
+ return leastSigBits & 0x0000FFFFFFFFFFFFL;
+ }
+
+ // Object Inherited Methods
+
+ /**
+ * Returns a {@code String} object representing this {@code UUID}.
+ *
+ * <p> The UUID string representation is as described by this BNF:
+ * <blockquote><pre>
+ * {@code
+ * UUID = <time_low> "-" <time_mid> "-"
+ * <time_high_and_version> "-"
+ * <variant_and_sequence> "-"
+ * <node>
+ * time_low = 4*<hexOctet>
+ * time_mid = 2*<hexOctet>
+ * time_high_and_version = 2*<hexOctet>
+ * variant_and_sequence = 2*<hexOctet>
+ * node = 6*<hexOctet>
+ * hexOctet = <hexDigit><hexDigit>
+ * hexDigit =
+ * "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"
+ * | "a" | "b" | "c" | "d" | "e" | "f"
+ * | "A" | "B" | "C" | "D" | "E" | "F"
+ * }</pre></blockquote>
+ *
+ * @return A string representation of this {@code UUID}
+ */
+ public String toString() {
+ char[] chars = new char[36];
+ jla.formatUnsignedLong(mostSigBits >> 32, 4, chars, 0, 8);
+ chars[8] = '-';
+ jla.formatUnsignedLong(mostSigBits >> 16, 4, chars, 9, 4);
+ chars[13] = '-';
+ jla.formatUnsignedLong(mostSigBits, 4, chars, 14, 4);
+ chars[18] = '-';
+ jla.formatUnsignedLong(leastSigBits >> 48, 4, chars, 19, 4);
+ chars[23] = '-';
+ jla.formatUnsignedLong(leastSigBits, 4, chars, 24, 12);
+ return jla.newStringUnsafe(chars);
+ }
+
+ /**
+ * Returns a hash code for this {@code UUID}.
+ *
+ * @return A hash code value for this {@code UUID}
+ */
+ public int hashCode() {
+ long hilo = mostSigBits ^ leastSigBits;
+ return ((int)(hilo >> 32)) ^ (int) hilo;
+ }
+
+ /**
+ * Compares this object to the specified object. The result is {@code
+ * true} if and only if the argument is not {@code null}, is a {@code UUID}
+ * object, has the same variant, and contains the same value, bit for bit,
+ * as this {@code UUID}.
+ *
+ * @param obj
+ * The object to be compared
+ *
+ * @return {@code true} if the objects are the same; {@code false}
+ * otherwise
+ */
+ public boolean equals(Object obj) {
+ if ((null == obj) || (obj.getClass() != UUID.class))
+ return false;
+ UUID id = (UUID)obj;
+ return (mostSigBits == id.mostSigBits &&
+ leastSigBits == id.leastSigBits);
+ }
+
+ // Comparison Operations
+
+ /**
+ * Compares this UUID with the specified UUID.
+ *
+ * <p> The first of two UUIDs is greater than the second if the most
+ * significant field in which the UUIDs differ is greater for the first
+ * UUID.
+ *
+ * @param val
+ * {@code UUID} to which this {@code UUID} is to be compared
+ *
+ * @return -1, 0 or 1 as this {@code UUID} is less than, equal to, or
+ * greater than {@code val}
+ *
+ */
+ public int compareTo(UUID val) {
+ // The ordering is intentionally set up so that the UUIDs
+ // can simply be numerically compared as two numbers
+ return (this.mostSigBits < val.mostSigBits ? -1 :
+ (this.mostSigBits > val.mostSigBits ? 1 :
+ (this.leastSigBits < val.leastSigBits ? -1 :
+ (this.leastSigBits > val.leastSigBits ? 1 :
+ 0))));
+ }
+}