private String peekUrl(String filename){
		String firstUrl = "";
		try{
			int i = 0;
			BufferedReader in = new BufferedReader(new FileReader(filename));
			String tmpFileName = filename + ".tmp";
			BufferedWriter bw = new BufferedWriter(new FileWriter(tmpFileName));
			String line = "";
			while((line = in.readLine()) != null){
				if(i == 0){
					firstUrl = line;
					i++;
					continue;
				}
				bw.write(line + "\r\n");
			}
			in.close();
			bw.close();
			FileUtils.delete(filename);
			FileUtils.rename(tmpFileName , filename);
		}catch (Exception ex){
			log.error("Peek URL failed: " + ex);
		}
		return firstUrl;
	}