Reading assets or raw or resource files as a File object in Android

Question

I have a jar file for which i need to pass file object. How can i pass resource or assets to that method as a file object?

How to convert assets or raw files in the project folders in to file objects ?

Answer 1

Here is what I did:

Copy Your asset file into SDCard:

AssetManager assetManager = context.getResources().getAssets();

String[] files = null;

try {
    files = assetManager.list("ringtone"); //ringtone is folder name
} catch (Exception e) {
    Log.e(LOG_TAG, "ERROR: " + e.toString());
}

for (int i = 0; i < files.length; i++) {
    InputStream in = null;
    OutputStream out = null;
    try {
        in = assetManager.open("ringtone/" + files[i]);
        out = new FileOutputStream(basepath + "/ringtone/" + files[i]);

        byte[] buffer = new byte[65536 * 2];
        int read;
        while ((read = in.read(buffer)) != -1) {
            out.write(buffer, 0, read);
        }
        in.close();
        in = null;
        out.flush();
        out.close();
        out = null;
        Log.d(LOG_TAG, "Ringtone File Copied in SD Card");
    } catch (Exception e) {
        Log.e(LOG_TAG, "ERROR: " + e.toString());
    }
}

Then read your file by the path:

File ringFile = new File(Environment.getExternalStorageDirectory().toString() + "/ringtone", "fileName.mp3");

There you go. You have a copy of file object of your asset file. Hope this helps.

Answer 2

To Read raw files into File.

    InputStream ins = getResources().openRawResource(R.raw.my_db_file);
    ByteArrayOutputStream outputStream=new ByteArrayOutputStream();
    int size = 0;
    // Read the entire resource into a local byte buffer.
    byte[] buffer = new byte[1024];
    while((size=ins.read(buffer,0,1024))>=0){
      outputStream.write(buffer,0,size);
    }
    ins.close();
    buffer=outputStream.toByteArray();

    FileOutputStream fos = new FileOutputStream("mycopy.db");
    fos.write(buffer);
    fos.close();

To avoid OutOfMemory apply following logic.

Don't create a huge ByteBuffer that contains ALL of the data at once. Create a much smaller ByteBuffer, fill it with data, then write this data to the FileChannel. Then reset the ByteBuffer and continue until all the data is written.