java io字节缓冲流

package qwe;

import java.io.*;

public class InOut5 {
    
    public static void main(String[] args) {
        FileInputStream fileInputStream = null;
        FileOutputStream fileOutputStream = null;

        BufferedInputStream bufferedInputStream = null;
        BufferedOutputStream bufferedOutputStream = null;
        try {
            File srcFile = new File("C:/work/cat.jfif");
            File destFile = new File("C:/work/cat2.jfif");

            fileInputStream=  new FileInputStream(srcFile);
            fileOutputStream = new FileOutputStream(destFile);

            bufferedInputStream =  new BufferedInputStream(fileInputStream);
            bufferedOutputStream = new BufferedOutputStream(fileOutputStream);

            byte[] b = new byte[1024];
            int len = 0;

            while ((len=bufferedInputStream.read(b))!=-1){
                bufferedOutputStream.write(b, 0, len);
            }

        }catch (Exception e){
            e.printStackTrace();
        }finally {

            //关闭外层即可自动关闭里层流
            try {
                if(bufferedInputStream!=null){
                    bufferedInputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            try {
                if(bufferedOutputStream!=null){
                    bufferedOutputStream.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}