Convert IP from String to long

I wrote this for work, but we didn't need it. So in case someone else needs a java routine to convert an ip address from String to long and back again (and it needs to be compatible w/ the method used by Unix), here it is....

package com.td.wss.docs.util;

import java.util.StringTokenizer;

public class IpUtil
{
 public static long ipToLong(String ip)
 {
  StringTokenizer thisTok=new StringTokenizer(ip, ".", false);
  
  long outLong=0;
  
  outLong += Long.parseLong((String)thisTok.nextElement()) << 24;
  outLong += Long.parseLong((String)thisTok.nextElement()) << 16;
  outLong += Long.parseLong((String)thisTok.nextElement()) << 8;
  outLong += Long.parseLong((String)thisTok.nextElement());
  
  return outLong;
 }


 public static String longToIp(long ip)
 {
  String ip0, ip1, ip2, ip3;
  
  ip3 = String.valueOf((ip >> 24));
  ip2 = String.valueOf((ip & 0x00FF0000) >> 16);
  ip1 = String.valueOf((ip & 0x0000FF00) >> 8);
  ip0 = String.valueOf((ip & 0x000000FF));
  
  return ip3 + "." +
    ip2 + "." +
    ip1 + "." +
    ip0;
 }

 /**
  *  Results should match http://www.t1shopper.com/tools/calculate/ip-subnet/
  * @param args
  */  
 public static void main(String[] args)
 {
  // Test1
  runTest("255.255.255.255");
  
  // Test2
  runTest("127.0.0.1");

  // Test3
  runTest("0.0.0.0");

  // Test4
  runTest("12.33.158.6");
  
 }
 
 private static void runTest(String ip)
 {
  long result = ipToLong(ip);
  System.out.println("ip=" + ip + " as long " + result);
   
  String ipStr = longToIp(result);
  System.out.println("ip=" + result + " as ip " + ipStr);
 }

}