private void searchDoc(String file_name) throws Exception
		{
				Path file_name_path = new Path(src_path + "/" + file_name);
				FSDataInputStream in = fs.open(file_name_path);
				BufferedReader br_in = new BufferedReader(new InputStreamReader(in));
				String message_in;
				int line_num = 0;
			    while( (message_in = br_in.readLine()) != null)
				{
						line_num++;
						for(String search_word : search_words)
						{
								String compared_message_in = new String(message_in);
								if(ignore_case_flag == true)
								{
										compared_message_in = compared_message_in.toLowerCase();
										search_word = search_word.toLowerCase();
								}

								String pattern_string = new String("\\b(" + search_word +")\\b");
								Pattern pattern = Pattern.compile(pattern_string);
								Matcher matcher = pattern.matcher(compared_message_in);
//								if(message_in.indexOf(search_word) != -1)
								if(matcher.find())
								{
										System.out.println("line" + line_num + ":" + message_in);
//										System.out.println("line" + line_num + ":" + matcher.group(1));
								}
						}
				}
		}