uuid.java

jxme的一些相关程序,主要是手机上程序开发以及手机和计算机通信的一些程序资料,程序编译需要Ant支持

/************************************************************************
 *
 * $Id: UUID.java,v 1.2 2002/03/04 21:42:58 echtcherbina Exp $
 *
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *********************************************************************************/

package net.jxta.impl.id.UUID;

import java.io.Serializable;

/**
 * A <code>UUID</code> is a 128-bit universally unique identifier.
 * The most significant long can be decomposed into the following
 * unsigned fields:
 * <pre>
 * 0xFFFFFFFF00000000 time_low
 * 0x00000000FFFF0000 time_mid
 * 0x000000000000F000 version
 * 0x0000000000000FFF time_hi
 * </pre>
 * The least significant long can be decomposed into the following
 * unsigned fields:
 * <pre>
 * 0xC000000000000000 variant
 * 0x3FFF000000000000 clock_seq
 * 0x0000FFFFFFFFFFFF node
 * </pre>
 *
 * The variant field must be 0x2. The version field must be either 0x1 or 0x4.
 * If the version field is 0x4, then the most significant bit of the node
 * field must be set to 1, and the remaining fields are set to values
 * produced by a cryptographically strong pseudo-random number generator.
 * If the version field is 0x1, then the node field is set to an IEEE 802
 * address, the clock_seq field is set to a 14-bit random number, and the
 * time_low, time_mid, and time_hi fields are set to the least, middle and
 * most significant bits (respectively) of a 60-bit timestamp measured in
 * 100-nanosecond units since midnight, October 15, 1582 UTC.
 *
 * @see         net.jxta.id.ID
 * @see         net.jxta.id.IDFactory
 * @see         net.jxta.impl.id.UUID.UUIDFactory
 *
 * @version $Revision: 1.2 $
 * @since       JXTA 1.0
 *
 */

public final class UUID implements Serializable {
    
    /**
     * The most significant 64 bits.
     *
     */
    
    private long mostSig;
    
    /**
     * The least significant 64 bits.
     *
     */
    
    private long leastSig;
    
    /**
     * Simple constructor.
     *
     * @param mostSig the most significant 64 bits
     * @param leastSig the lease significant 64 bits
     *
     * @since       JXTA 1.0
     */
    
    public UUID(long mostSig, long leastSig) {
        this.mostSig = mostSig;
        this.leastSig = leastSig;
    }
    
    /**
     * Returns the most significant 64 bits of the UUID.
     *
     * @return long return most significant bits
     *
     * @since       JXTA 1.0
     */
    
    public long getMostSignificantBits() {
        return mostSig;
    }
    
    /**
     * Returns the least significant 64 bits of the UUID.
     *
     * @return long lesat significant bits
     *
     * @since       JXTA 1.0
     */
    
    public long getLeastSignificantBits() {
        return leastSig;
    }
    
    /**
     * Returns the hash code of the UUID
     *
     * @return int hashcode
     *
     * @since       JXTA 1.0
     */
    
    public int hashCode() {
        return (int)((mostSig >> 32) ^ mostSig ^ (leastSig >> 32) ^ leastSig);
    }
    
    /**
     * Compares two UUIDs for equality.
     *
     * @param target  the CodatID to be compared against.
     * @return	boolean true if CodatIds are equal, false otherwise.
     *
     *  @since JXTA 1.0
     */
    public boolean equals( Object target ) {
        if (this == target)
            return true;
        
        if (target instanceof UUID) {
            return equals( (UUID) target );
        }
        else
            return false;
    }
    
    /**
     * UUIDs are equal if they represent the same 128-bit value.
     *
     * @param sid UUID seed
     * @return boolean true if equals
     *
     * @since       JXTA 1.0
     */
    
    public boolean equals(UUID sid) {
        return (mostSig == sid.mostSig && leastSig == sid.leastSig);
    }
    
    /**
     * Returns a 36-character string of six fields separated by hyphens,
     * with each field represented in lowercase hexadecimal with the same
     * number of digits as in the field. The order of fields is: time_low,
     * time_mid, version and time_hi treated as a single field, variant and
     * clock_seq treated as a single field, and node.
     *
     * @return String return value
     *
     * @since       JXTA 1.0
     */
    
    public String toString() {
        return (digits(mostSig >> 32, 8) + "-" +
        digits(mostSig >> 16, 4) + "-" +
        digits(mostSig, 4) + "-" +
        digits(leastSig >> 48, 4) + "-" +
        digits(leastSig, 12));
    }
    
    /**
     * Returns val represented by the specified number of hex digits
     *
     * @param val value
     * @param digits
     * @return String return value
     *
     * @since       JXTA 1.0
     */
    
    private static String digits(long val, int digits) {
        long hi = 1L << (digits * 4);
        return Long.toHexString(hi | (val & (hi - 1))).substring(1);
    }
}