private static String lineProcess(String line, ArrayList<String> stopWordsArray) throws IOException {
		// TODO Auto-generated method stub
		//step1 ӢĴʷȥַ֡šַддĸתСдԿʽ
		String res[] = line.split("[^a-zA-Z]");
		//ҪСģֹемַֺĵ ضˣǽضҲû
		
		String resString = new String();
		//step2ȥͣô
		//step3stemming,غһ
		for(int i = 0; i < res.length; i++){
			if(!res[i].isEmpty() && !stopWordsArray.contains(res[i].toLowerCase())){
				resString += " " + res[i].toLowerCase() + " ";
			}
		}
		return resString;
	}