java 緩衝區複製文本文件

public class CopyTextByBuf {
    public static void main(String[] args) {
        BufferedReader bufr = null;
        BufferedWriter bufw = null;
        try {
            bufr = new BufferedReader(new FileReader("demo_src.txt"));
            bufw = new BufferedWriter(new FileWriter("demo_desc.txt"));
            String line = null;
            //readLine不帶行終止符
            while ((line = bufr.readLine()) != null) {
                bufw.write(line);
                bufw.newLine();
                bufw.flush();
            }
        } catch (IOException e) {
            throw new RuntimeException("讀寫失敗!");
        } finally {
            try {
                if (bufr != null)
                    bufr.close();
            } catch (IOException e) {
                throw new RuntimeException("讀取關閉失敗！");
            }
            try {
                if (bufw != null)
                    bufw.close();
            } catch (IOException e) {
                throw new RuntimeException("寫入關閉失敗！");
            }
        }
    }
}

newLine()
無論讀一行還是獲取多個字元，其實最終都是在硬碟上一個一個讀取。所以最終使用的還是read()一次讀一個的方法。