UUID生成器

UUIDHexGeneral.java

package com.lmb.util;/*** UUID.HEX十六进制生成器：IP地址+JVM+当地时间+计数器*/import java.net.InetAddress;public class UUIDHexGenerator {    private String sep = "";    private static final int IP;    private static short counter = (short) 0;    private static final int JVM = (int)(System.currentTimeMillis() >>> 8);    private static UUIDHexGenerator uuidgen = new UUIDHexGenerator();    //获得本机的IP地址    static {       int ipadd;       try {        ipadd = toInt(InetAddress.getLocalHost().getAddress());       } catch (Exception e) {        ipadd = 0;       }       IP = ipadd;    }    //获取UUIDHexGenerator实例对象    public static UUIDHexGenerator getInstance() {       return uuidgen;    }    //将byte类型变量转化为Int类型    public static int toInt(byte[] bytes) {       int result = 0;       for (int i = 0; i < 4; i++) {        result = (result << 8) - Byte.MIN_VALUE + (int) bytes[i];       }       return result;    }    //将int类型变量转化为string类型    protected String format(int intval) {       String formatted = Integer.toHexString(intval);       StringBuffer buf = new StringBuffer("00000000");       buf.replace(8 - formatted.length(), 8, formatted);       return buf.toString();    }    //将byte类型变量转化为string类型    protected String format(short shortval) {       String formatted = Integer.toHexString(shortval);       StringBuffer buf = new StringBuffer("0000");       buf.replace(4 - formatted.length(), 4, formatted);       return buf.toString();    }    protected int getJVM() {       return JVM;    }    protected synchronized short getCount() {       if (counter < 0) {        counter = 0;       }       return counter++;    }    protected int getIP() {       return IP;    }    protected short getHiTime() {       return (short) (System.currentTimeMillis() >>> 32);    }    protected int getLoTime() {       return (int) System.currentTimeMillis();    }    public String generate() {       return new StringBuffer(36).append(format(getIP())).append(sep).append(         format(getJVM())).append(sep).append(format(getHiTime()))         .append(sep).append(format(getLoTime())).append(sep).append(           format(getCount())).toString();    }    public static void main(String[] str) {       UUIDHexGenerator id = new UUIDHexGenerator();       for (int i = 0; i <= 10; i++) {        System.out.println(id.generate());       }       System.out.println(id.generate().length());    }}