文件输入字节流(InputStream)

public class InputByStream {
     public static void main(String args[ ]){
           try {
            FileInputStream fis = new FileInputStream("learn.txt");
            byte b[] = new byte[1024];
            
            fis.read(b);
            
            String str = new String(b, "UTF-8");
            
            System.out.println(str);
             
            fis.close();
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }  
     }
}