Web Development

import java.util.*;
import java.net.*;
import java.security.*;
 
//	stuff for GUIDs
private SecureRandom	m_secureRandom;
private String	m_strIP;
 
// in your constructor somewhere
{
	m_secureRandom = new SecureRandom();
 
	try
	{
		m_strIP = InetAddress.getLocalHost().toString(); 
	}
	catch (UnknownHostException e)
	{
		//  Handle the exception, possibly setting the IP to some 162.xxx.xxx.xxx
		//  number.
	}
}
 
private String	GenerateGUID()
{
	try
	{
		StringBuffer	sGUID = new StringBuffer();
		StringBuffer	sRaw = new StringBuffer();
		MessageDigest	md5 = MessageDigest.getInstance("MD5");
		long	time = System.currentTimeMillis();
		long	rand = m_secureRandom.nextLong();
 
		sRaw.append(m_strIP);
		sRaw.append(".");
		sRaw.append(Long.toString(time));
		sRaw.append(".");
		sRaw.append(Long.toString(rand));
 
		md5.update(sRaw.toString().getBytes());
 
		byte[]	raw = md5.digest();
 
		for (int i = 0; i < raw.length; i++)
		{
			int	x = raw[i] & 0xff;
 
			if (x < 0x10)	sGUID.append('0');
 
			sGUID.append(Integer.toHexString(x));
		}
 
		return sGUID.toString().toUpperCase();
	}
	catch (Exception  e)
	{
		e.printStackTrace();
	}
 
	return "";
}