一、利用字节流实现媒体文件的拷贝：

    public static void copyMedia() throws IOException {

        long l1 = System.currentTimeMillis();
        FileInputStream fis = new FileInputStream("d:\\往南.mp3");
        FileOutputStream fos = new FileOutputStream("g:\\往南.mp3");

        byte[] buf = new byte[fis.available()];
        fis.read(buf);
        fos.write(buf);
        fos.close();
        fis.close();

        ong l2 = System.currentTimeMillis();
        System.out.println(l2 - l1);
    }

结果：33

二、利用缓冲区提高效率

public static void copy2() throws IOException {

        long l1 = System.currentTimeMillis();
        FileInputStream fis = new FileInputStream("d:\\往南.mp3");
        BufferedInputStream bufis = new BufferedInputStream(fis);

        FileOutputStream fos = new FileOutputStream("g:\\往南1.mp3");
        BufferedOutputStream bufos = new BufferedOutputStream(fos);

        byte[] buf = new byte[bufis.available()];
        bufis.read(buf);
        bufos.write(buf);

        bufos.close();
        bufis.close();

        long l2 = System.currentTimeMillis();
        System.out.println(l2 - l1);
    }

结果：10