Java字节流读取写出文件

操作非文本文件 图片视频等等

public class Test13 {
    public static void main(String[] args) {
        FileInputStream inputStream = null;
        FileOutputStream outputStream = null;
        //输入流
        try {
             //参数传入文件位置
            inputStream = new FileInputStream("D://作业.png");
            //输出流
            outputStream = new FileOutputStream("D://作业副本.png");

            //复制的过程
            byte[] bytes = new byte[1024];
            int len;
            while ((len = inputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, len);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                inputStream.close();
                outputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

    }
}

运行测试

文本文件

        FileInputStream inputStream=null;
        try {
            inputStream = new FileInputStream("D://1.txt");
            byte[] bytes = new byte[1024];
            //记录每次读取的字节个数
            int len;
            while ((len=inputStream.read(bytes))!=-1){
                String str = new String(bytes, 0, len);
                System.out.println(str);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }