java 输入流获取文本内容

1.流为FileInputStream

 FileInputStream fileInputStream = new FileInputStream("D:/a.txt");
        byte[] b =  new byte[1024];
        int i = 0;
        while ((i = fileInputStream.read(b)) != -1) {
            String str = new String(b);
            System.out.print(str);
        }

2.流为InputStream

  byte[] bytes = FileCopyUtils.copyToByteArray("这里写InputStream");
        String str = new String(bytes, "UTF-8");