java之 BufferedInputStream和BufferedOutputStream

BufferedInputStream和BufferedOutputStream

BufferedInputStream 官方文档解释

class BufferedInputStream extends FilterInputStream {

    private static int DEFAULT_BUFFER_SIZE = 8192;
}

//java内部限定读取大小8Kb
相当于 byte[] bytes=new byte[1024*8];

package com.feng;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class Demo01 {
public static void main(String[] args) throws IOException {
	/*
	 * 	BufferedInputStream和BufferedOutputStream
	 *  这两个流是内置了缓冲区流 ，也就是说内部有一个字节数组
	 * 
	 */
		//1.创建一个缓冲输入流
		BufferedInputStream bis=new BufferedInputStream(new FileInputStream("C:/Users/Zhanglinfeng/Desktop/ma.png"));
//		FileInputStream fis=new FileInputStream("C:/Users/Zhanglinfeng/Desktop/ma.png");
//		BufferedInputStream bis=new BufferedInputStream(fis);
		
		//2.创建一个缓冲输出流
//		FileOutputStream fos=new FileOutputStream("C:/Users/Zhanglinfeng/Desktop/ma-副本.png");
//		BufferedOutputStream bos=new BufferedOutputStream(fos);
		BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream("C:/Users/Zhanglinfeng/Desktop/ma-副本.png"));
		//3.输入流读数据，输出流写数据
		int len=0;
		while ((len=bis.read())!=-1) {
			//bis.read()方法内部一次读取8kb
			bos.write(len);//内部写入8kb
		}
		//4.关闭流，只需要关闭缓冲流【内部自动关闭文件流close方法】，文件流不用关;
		
		bis.close();
		bos.close();
	System.out.println("文件拷贝成功 !");
}

}