讀檔案時，產生大量的記憶體無法釋放，麻煩各位看一下

public void loadData() {
		String fileName = "D:/data.txt";
		try {
			FileReader fr = new FileReader(fileName);
			BufferedReader bfr = new BufferedReader(fr);

			String str = null;
			List dataList = new ArrayList(0);
			while ((str = bfr.readLine()) != null) {
				String[] line = str.split("\t");
				dataList.add(line);
			}

			bfr.close();
			fr.close();

		} catch (Exception e) {
			
		}
	}