Android:如何以字节为单位读取文件? [英] Android : How to read file in bytes?

问题描述

我试图在 Android 应用程序中以字节为单位获取文件内容.我已经在 SD 卡中获取了文件，现在想要以字节为单位获取所选文件.我用谷歌搜索但没有这样的成功.请帮忙

I am trying to get file content in bytes in Android application. I have get the file in SD card now want to get the selected file in bytes. I googled but no such success. Please help

以下是获取带扩展名的文件的代码.通过这个我得到文件并在微调器中显示.在文件选择上，我想以字节为单位获取文件.

Below is the code to get files with extension. Through this i get files and show in spinner. On file selection I want to get file in bytes.

private List<String> getListOfFiles(String path) {

   File files = new File(path);

   FileFilter filter = new FileFilter() {

      private final List<String> exts = Arrays.asList("jpeg", "jpg", "png", "bmp", "gif","mp3");

      public boolean accept(File pathname) {
         String ext;
         String path = pathname.getPath();
         ext = path.substring(path.lastIndexOf(".") + 1);
         return exts.contains(ext);
      }
   };

   final File [] filesFound = files.listFiles(filter);
   List<String> list = new ArrayList<String>();
   if (filesFound != null && filesFound.length > 0) {
      for (File file : filesFound) {
         list.add(file.getName());
      }
   }
   return list;
}

推荐答案

这里很简单:

File file = new File(path);
int size = (int) file.length();
byte[] bytes = new byte[size];
try {
    BufferedInputStream buf = new BufferedInputStream(new FileInputStream(file));
    buf.read(bytes, 0, bytes.length);
    buf.close();
} catch (FileNotFoundException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
} catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}

在 manifest.xml 中添加权限:

Add permission in manifest.xml:

 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

这篇关于Android:如何以字节为单位读取文件?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！