sessionTempDirStr = tempRootDirStr + File.separator + prefix + System.currentTimeMillis( );
i++; sessionTempDirStr = sessionTempDirStr + "_" + i;
	public static String createSessionTempDir( String tempRootDirStr )	{		String sessionTempDirStr;		final String prefix = "session_";		sessionTempDirStr = tempRootDirStr + File.separator + prefix + System.currentTimeMillis( );		File file = new File( sessionTempDirStr );		synchronized ( CacheUtil.class )		{			while ( file.exists( ) )			{				sessionTempDirStr = tempRootDirStr						+ File.separator + prefix + System.currentTimeMillis( );				file = new File( sessionTempDirStr );			}			file.mkdir( );		}		return sessionTempDirStr;	}