Java緩沖位元組流BufferedOutputStream(輸出),BufferedInputStream(輸入),對檔案的複制操作

public static void main(String[] args) throws IOException {
		//bufferedOutput();
		//bufferedInput();
		//copyFile();
	}
	/**
	 * 檔案複制操作(操作檔案最快)
	 * @throws IOException
	 */
	private static void copyFile() throws IOException {
		BufferedInputStream bis = new BufferedInputStream(new FileInputStream("D:\\test.avi"));
		BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream("F:\\test.avi"));
		byte[] bytes = new byte[1024];
		int len = 0;
		while((len = bis.read(bytes)) != -1){
			bos.write(bytes, 0, len);
		}
		bos.close();
		bis.close();
		System.out.println("複制完成");
		
	}
	/**
	 * BufferedInputStream:提升讀取效率,執行順序和BufferedOutputStream一樣
	 */
	private static void bufferedInput() throws IOException{
		BufferedInputStream bis = new BufferedInputStream(new FileInputStream("D:\\a.txt"));
		byte[] b = new byte[1024];
		int len = 0;
		while((len = bis.read(b)) != -1){
			System.out.println(new String(b, 0, len));
		}
		bis.close();//關閉緩沖流也會吧位元組流關閉
	}
	/**
	 * BufferedOutputStream:提升寫入效率
	 * 	沒提升效率前順序:程式->JVM->計算機底層寫入(每次讀取*位元組,每次都調用一次計算機底層)
	 * 提升效率後:程式->JVM(先不調用計算機底層,先将資料緩沖,資料讀取完畢後->計算機底層)
	 * OutputStream的子類,使用方法都一樣
	 */
	private static void bufferedOutput() throws IOException{
		FileOutputStream fos = new FileOutputStream("D:\\a.txt");
		BufferedOutputStream bos = new BufferedOutputStream(fos);//傳入要提升效率的位元組輸出流
		bos.write("HelloWorld".getBytes());
		bos.close();
		System.out.println("寫入完成");
	}