定义:

二进制流 对象=new 二进制流(字节流)

DataInputStream dataInputStream = new DataInputStream(inputStream);

实现copy一个文件:

import java.io.*;

public class filecopydata {
    public static void main(String[] args) throws IOException {
        InputStream inputStream=null;
        OutputStream OutputStream=null;
        DataInputStream dataInputStream=null;
        DataOutputStream dataOutputStream=null;
        //定义字节流
        try {
             inputStream = new FileInputStream(new File("d:/介绍.txt"));
             OutputStream = new FileOutputStream(new File("d:/实际介绍.txt"));
             dataInputStream = new DataInputStream(inputStream); //二进制流
             dataOutputStream = new DataOutputStream(OutputStream);
            byte[]  buf=new byte[6];
            int len=-1;
            while((len=dataInputStream.read(buf)) != -1){
                dataOutputStream.write(buf,0,len);
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            dataOutputStream.close();;
            dataInputStream.close();
            OutputStream.close();
            inputStream.close();
        }
    }
}