Android app can't read external storage files

Question

I\'m creating an app for a private use only... it\'s not so important then, respect your time :P

What I want to make is an app that reads from a database and plays s

Answer 1

Here is the code @Nisarg, had to clean it a bit:

import android.Manifest;
import android.content.pm.PackageManager;
import android.media.MediaPlayer;
import android.os.Build;
import android.os.Bundle;
import android.os.Environment;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

import java.io.File;

public class MainActivity extends AppCompatActivity implements OnClickListener {

Button readExcelButton;
static String TAG = "ExelLog";
MediaPlayer mpintro;

@Override
public void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    if (Build.VERSION.SDK_INT == Build.VERSION_CODES.M) {
        Toast.makeText(this, "Permission checking", Toast.LENGTH_SHORT).show();
        checkPermission();
    }

    readExcelButton = (Button) findViewById(R.id.readExcel);
    readExcelButton.setOnClickListener(this);

}

public void onClick(View v)
{
    switch (v.getId())
    {
        case R.id.readExcel:
            String filePath = getExternalFilesDir(null) + "/p0000.mp3";
            File file = new File(filePath);
            file.setReadable(true);
            file.setWritable(true);

            if (!isExternalStorageAvailable() || isExternalStorageReadOnly()) {
                Toast.makeText(this, "Ext storage not available or read only", Toast.LENGTH_SHORT).show();
            }
            else {
                Toast.makeText(this, "Ext storage available", Toast.LENGTH_SHORT).show();
            }

            if (file.exists()){
                Toast.makeText(this, "File found", Toast.LENGTH_SHORT).show();
            }
            else {
                Toast.makeText(this, getExternalFilesDir(null) + "/p0000.mp3 - File not found", Toast.LENGTH_LONG).show();
            }

            break;
    }
}

private void checkPermission() {
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this,
            Manifest.permission.READ_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {//Can add more as per requirement

        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.READ_EXTERNAL_STORAGE},
                123);

    } else {

    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case 123: {

            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED)     {
                //Peform your task here if any
            } else {

                checkPermission();
            }
            return;
        }
    }
}

public static boolean isExternalStorageReadOnly() {
    String extStorageState = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(extStorageState)) {
        return true;
    }
    return false;
}

public static boolean isExternalStorageAvailable() {
    String extStorageState = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(extStorageState)) {
        return true;
    }
    return false;
}

}