Question

I have button that plays sound using soundpool. I want to open my application and then manually load .mp3 file from SD card and play it with my button.
My java code :

package com.example.idea;

    import android.media.SoundPool;
    import android.os.Bundle;
    import android.app.Activity;
    import android.view.Menu;
    import android.view.View;

    public class MainActivity extends Activity {
    SoundPool sp;
    int mSoundId;
    int mStreamId;
    @Override
    public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mSoundId = sp.load(this, R.raw.sound1, 1);

}

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

    public void button1(View view){
    if (mStreamId != 0) {
    sp.stop(mStreamId);
}
    `mStreamId = sp.play(mSoundId, 1, 1, 1, 0, 1f);`
}
}

Answer 1

Since your SD card is usually (but necessarily) your external storage, I’ll present such a solution below. (If your external storage points to an internal card in your device — e.g. on a tablet –, my code will return a path to that folder.)

Therefore, you should use another version of the load method of SoundPool, which expects a file path (as a String) instead of a resource ID. This is the official link to the method’s documentation. To get the path of the file, you can use this method:

private String getFullFilePath(Context context, String filename) {  
    File directory = context.getExternalFilesDir(null);
    File file = new File(directory, filename);
    if (!file.canRead()) {
        // error handling
    }
    return file.getAbsolutePath();  
}

In this case, your relevant code snippet would look like this:

String path = getFullFilePath(getApplicationContext(), "sound1.wav");
mSoundId = sp.load(path, 1);

To sum up, the above code will search for the file in your application’s external storage directory. This is the standard way of accessing a non-internal storage file (i.e. it’s device dependent if the external storage is your SD card or something else).

---

UPDATE:

Of course, before using the external storage, you should check whether the media is readable (and in case of writing requirements, writable). You can find more information on this official page.