UUIDGenerator (生成32位uuid串)

import java.io.Serializable;
import java.net.InetAddress;

public class UUIDGenerator {

	/**
	 * Description:生成形如‘2c9081261d50d1c4011d50d1c4320000’的32位uuid串
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		UUIDGenerator uuidGenerator = new UUIDGenerator();
		System.out.println(uuidGenerator.generate().toString());
	}
	 private static final int IP;
	 public static int IptoInt( byte[] bytes ) {
	  int result = 0;
	  for (int i=0; i<4; i++) {
	   result = ( result << 8 ) - Byte.MIN_VALUE + (int) bytes[i];
	  }
	  return result;
	 }
	 static {
	  int ipadd;
	  try {
	   ipadd = IptoInt( InetAddress.getLocalHost().getAddress() );
	  }
	  catch (Exception e) {
	   ipadd = 0;
	  }
	  IP = ipadd;
	 }
	 private static short counter = (short) 0;
	 private static final int JVM = (int) ( System.currentTimeMillis() >>> 8 );

	 public UUIDGenerator() {
	 }

	 /**
	  * Unique across JVMs on this machine (unless they load this class
	  * in the same quater second - very unlikely)
	  */
	 protected int getJVM() {
	  return JVM;
	 }

	 /**
	  * Unique in a millisecond for this JVM instance (unless there
	  * are > Short.MAX_VALUE instances created in a millisecond)
	  */
	 protected short getCount() {
	  synchronized(UUIDGenerator.class) {
	   if (counter<0) counter=0;
	   return counter++;
	  }
	 }

	 /**
	  * Unique in a local network
	  */
	 protected int getIP() {
	  return IP;
	 }

	 /**
	  * Unique down to millisecond
	  */
	 protected short getHiTime() {
	  return (short) ( System.currentTimeMillis() >>> 32 );
	 }
	 protected int getLoTime() {
	  return (int) System.currentTimeMillis();
	 }
	 
	 private final static String sep = "";

	 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();
	 }

	 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();
	 }

	 public Serializable 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();
	 }
}

用法:  String abc = new UUIDGenerator().generate().toString();