Android : How to read file in bytes?

Question

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

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; } 

Answer 1

here it's a simple:

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(); } 

Add permission in manifest.xml:

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

Answer 2

The easiest solution today is to used Apache common io :

http://commons.apache.org/proper/commons-io/javadocs/api-release/org/apache/commons/io/FileUtils.html#readFileToByteArray(java.io.File)

byte bytes[] = FileUtils.readFileToByteArray(photoFile) 

The only drawback is to add this dependency in your build.gradle app :

implementation 'commons-io:commons-io:2.5' 

+ 1562 Methods count