/*
* UUID.java
*
* Created 07.02.2003
*
* eaio: UUID - an implementation of the UUID specification
* Copyright (c) 2003-2009 Johann Burkard (jb@eaio.com) http://eaio.com.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
* NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
package com.eaio.uuid;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import org.omg.CORBA.portable.IDLEntity;
import com.eaio.util.lang.Hex;
/**
* Creates UUIDs according to the DCE Universal Token Identifier specification.
* <p>
* All you need to know:
* <pre>
* UUID u = new UUID();
* </pre>
*
* @see <a href="http://www.opengroup.org/onlinepubs/9629399/apdxa.htm">
* http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
* </a>
* @see <a href="http://www.uddi.org/pubs/draft-leach-uuids-guids-01.txt">
* http://www.uddi.org/pubs/draft-leach-uuids-guids-01.txt
* </a>
* @see <a href="http://johannburkard.de/software/uuid/">UUID</a>
* @author <a href="mailto:jb@eaio.de">Johann Burkard</a>
* @version $Id: UUID.java 1888 2009-03-15 12:43:24Z johann $
*/
public class UUID implements Comparable<UUID>, Serializable, Cloneable,
IDLEntity {
/**
* Hasn't ever changed between versions.
*/
static final long serialVersionUID = 7435962790062944603L;
/**
* The time field of the UUID.
*
* @serial
*/
public long time;
/**
* The clock sequence and node field of the UUID.
*
* @serial
*/
public long clockSeqAndNode;
/**
* Constructor for UUID. Constructs a new, unique UUID.
*
* @see UUIDGen#newTime()
* @see UUIDGen#getClockSeqAndNode()
*/
public UUID() {
this(UUIDGen.newTime(), UUIDGen.getClockSeqAndNode());
}
/**
* Constructor for UUID. Constructs a UUID from two <code>long</code> values.
*
* @param time the upper 64 bits
* @param clockSeqAndNode the lower 64 bits
*/
public UUID(long time, long clockSeqAndNode) {
this.time = time;
this.clockSeqAndNode = clockSeqAndNode;
}
/**
* Copy constructor for UUID. Values of the given UUID are copied.
*
* @param u the UUID, may not be <code>null</code>
*/
public UUID(UUID u) {
this(u.time, u.clockSeqAndNode);
}
/**
* Parses a textual representation of a UUID.
* <p>
* No validation is performed. If the {@link CharSequence} is shorter than 36 characters,
* {@link ArrayIndexOutOfBoundsException}s will be thrown.
*
* @param s the {@link CharSequence}, may not be <code>null</code>
*/
public UUID(CharSequence s) {
this(Hex.parseLong(s.subSequence(0, 18)), Hex.parseLong(s.subSequence(
19, 36)));
}
/**
* Compares this UUID to another Object. Throws a {@link ClassCastException} if
* the other Object is not an instance of the UUID class. Returns a value
* smaller than zero if the other UUID is "larger" than this UUID and a value
* larger than zero if the other UUID is "smaller" than this UUID.
*
* @param t the other UUID, may not be <code>null</code>
* @return a value < 0, 0 or a value > 0
* @see java.lang.Comparable#compareTo(java.lang.Object)
* @throws ClassCastException
*/
public int compareTo(UUID t) {
if (this == t) {
return 0;
}
if (time > t.time) {
return 1;
}
if (time < t.time) {
return -1;
}
if (clockSeqAndNode > t.clockSeqAndNode) {
return 1;
}
if (clockSeqAndNode < t.clockSeqAndNode) {
return -1;
}
return 0;
}
/**
* Tweaked Serialization routine.
*
* @param out the ObjectOutputStream
* @throws IOException
*/
private void writeObject(ObjectOutputStream out) throws IOException {
out.writeLong(time);
out.writeLong(clockSeqAndNode);
}
/**
* Tweaked Serialization routine.
*
* @param in the ObjectInputStream
* @throws IOException
*/
private void readObject(ObjectInputStream in) throws IOException {
time = in.readLong();
clockSeqAndNode = in.readLong();
}
/**
* Returns this UUID as a String.
*
* @return a String, never <code>null</code>
* @see java.lang.Object#toString()
* @see #toAppendable(Appendable)
*/
@Override
public final String toString() {
return toAppendable(null).toString();
}
/**
* Appends a String representation of this to the given {@link StringBuffer} or
* creates a new one if none is given.
*
* @param in the StringBuffer to append to, may be <code>null</code>
* @return a StringBuffer, never <code>null</code>
* @see #toAppendable(Appendable)
*/
public StringBuffer toStringBuffer(StringBuffer in) {
StringBuffer out = in;
if (out == null) {
out = new StringBuffer(36);
}
else {
out.ensureCapacity(out.length() + 36);
}
return (StringBuffer) toAppendable(out);
}
/**
* Appends a String representation of this object to the given {@link Appendable} object.
* <p>
* For reasons I'll probably never understand, Sun has decided to have a number of I/O classes implement
* Appendable which forced them to destroy an otherwise nice and simple interface with {@link IOException}s.
* <p>
* I decided to ignore any possible IOExceptions in this method.
*
* @param a the Appendable object, may be <code>null</code>
* @return an Appendable object, defaults to a {@link StringBuilder} if <code>a</code> is <code>null</code>
*/
public Appendable toAppendable(Appendable a) {
Appendable out = a;
if (out == null) {
out = new StringBuilder(36);
}
try {
Hex.append(out, (int) (time >> 32)).append('-');
Hex.append(out, (short) (time >> 16)).append('-');
Hex.append(out, (short) time).append('-');
Hex.append(out, (short) (clockSeqAndNode >> 48)).append('-');
Hex.append(out, clockSeqAndNode, 12);
}
catch (IOException ex) {
// What were they thinking?
}
return out;
}
/**
* Returns a hash code of this UUID. The hash code is calculated by XOR'ing the
* upper 32 bits of the time and clockSeqAndNode fields and the lower 32 bits of
* the time and clockSeqAndNode fields.
*
* @return an <code>int</code> representing the hash code
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
return (int) ((time >> 32) ^ time ^ (clockSeqAndNode >> 32) ^ clockSeqAndNode);
}
/**
* Clones this UUID.
*
* @return a new UUID with identical values, never <code>null</code>
*/
@Override
public Object clone() {
try {
return super.clone();
}
catch (CloneNotSupportedException ex) {
// One of Sun's most epic fails.
return null;
}
}
/**
* Returns the time field of the UUID (upper 64 bits).
*
* @return the time field
*/
public final long getTime() {
return time;
}
/**
* Returns the clock and node field of the UUID (lower 64 bits).
*
* @return the clockSeqAndNode field
*/
public final long getClockSeqAndNode() {
return clockSeqAndNode;
}
/**
* Compares two Objects for equality.
*
* @see java.lang.Object#equals(Object)
* @param obj the Object to compare this UUID with, may be <code>null</code>
* @return <code>true</code> if the other Object is equal to this UUID,
* <code>false</code> if not
*/
@Override
public boolean equals(Object obj) {
if (!(obj instanceof UUID)) {
return false;
}
return compareTo((UUID) obj) == 0;
}
/**
* Returns the nil UUID (a UUID whose values are both set to zero).
* <p>
* Starting with version 2.0, this method does return a new UUID instance every
* time it is called. Earlier versions returned one instance. This has now been
* changed because this UUID has public, non-final instance fields. Returning a
* new instance is therefore more safe.
*
* @return a nil UUID, never <code>null</code>
*/
public static UUID nilUUID() {
return new UUID(0, 0);
}
}
