READ_EXTERNAL_STORAGE permission for Android

Question

I'm trying to access media files (music) on the users device to play them; an easy "hello world"-music player app.

I've followed some tutorials and they basically give the same code. But it won't work; it keeps crashing and telling me:

error..... Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=27696, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission() .... 

Now, this is my manifest file:

<?xml version="1.0" encoding="utf-8"?> <manifest     xmlns:android="http://schemas.android.com/apk/res/android"     package="slimsimapps.troff" >      <uses-permission android:name="android.permission.MEDIA_CONTENT_CONTROL"/>     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>   <application     android:allowBackup="true"     android:icon="@mipmap/ic_launcher"     android:label="@string/app_name"     android:theme="@style/AppTheme" >     <activity         android:name=".MainActivity"         android:label="@string/app_name" >         <intent-filter>             <action android:name="android.intent.action.MAIN" />              <category android:name="android.intent.category.LAUNCHER" />         </intent-filter>     </activity> </application> </manifest> 

This is my Java-method:

public void initialize() {     ContentResolver contentResolver = getContentResolver();     Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;     Cursor cursor = contentResolver.query(uri, null, null, null, null);     if (cursor == null) {         // query failed, handle error.     } else if (!cursor.moveToFirst()) {         // no media on the device     } else {         do {             addSongToXML(cursor);         } while (cursor.moveToNext());     } } 

I have tried:

To put this at different places in the manifest file:

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

To add android:maxSdkVersion at Read external storage premission:

<uses-permission     android:name="android.permission.READ_EXTERNAL_STORAGE"     android:maxSdkVersion="21" /> 

To put this in the manifest / application / activity-tag:

android:exported=“true” 

To put grantUriPremission between uri and cursro in the javamethod:

grantUriPermission(null, uri, Intent.FLAG_GRANT_READ_URI_PERMISSION); 

To use this, it won't crash, but the cursor becomes null:

uri = MediaStore.Audio.Media.getContentUri("EXTERNAL_CONTENT_URI”); 

To use INTERNAL content uri, this works as expected, but it only gives "OS-sounds" such as shutter-sound, low-battery-sound, button-click and such:

uri = MediaStore.Audio.Media.INTERNAL_CONTENT_URI; 

Pleas help, this should not be a hard problem i know, but i feel like such a beginner!

I have read and tried (or considered them to be not applicable for my problem):

• Android READ_EXTERNAL_STORAGE permission not working
• Require permission only for older android versions: maxSdkVersion does not work?
• Get filename and path from URI from mediastore
• Android KitKat securityException when trying to read from MediaStore
• Android: java.lang.SecurityException: Permission Denial: start Intent

Stack trace:

09-08 06:59:36.619    2009-2009/slimsimapps.troff D/AndroidRuntime﹕ Shutting down VM     --------- beginning of crash 09-08 06:59:36.619    2009-2009/slimsimapps.troff E/AndroidRuntime﹕ FATAL EXCEPTION: main     Process: slimsimapps.troff, PID: 2009     java.lang.IllegalStateException: Could not execute method for android:onClick             at android.view.View$DeclaredOnClickListener.onClick(View.java:4452)             at android.view.View.performClick(View.java:5198)             at android.view.View$PerformClick.run(View.java:21147)             at android.os.Handler.handleCallback(Handler.java:739)             at android.os.Handler.dispatchMessage(Handler.java:95)             at android.os.Looper.loop(Looper.java:148)             at android.app.ActivityThread.main(ActivityThread.java:5417)             at java.lang.reflect.Method.invoke(Native Method)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)      Caused by: java.lang.reflect.InvocationTargetException             at java.lang.reflect.Method.invoke(Native Method)             at android.view.View$DeclaredOnClickListener.onClick(View.java:4447)             at android.view.View.performClick(View.java:5198)             at android.view.View$PerformClick.run(View.java:21147)             at android.os.Handler.handleCallback(Handler.java:739)             at android.os.Handler.dispatchMessage(Handler.java:95)             at android.os.Looper.loop(Looper.java:148)             at android.app.ActivityThread.main(ActivityThread.java:5417)             at java.lang.reflect.Method.invoke(Native Method)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)      Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=2009, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()             at android.os.Parcel.readException(Parcel.java:1599)             at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:183)             at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:135)             at android.content.ContentProviderProxy.query(ContentProviderNative.java:421)             at android.content.ContentResolver.query(ContentResolver.java:491)             at android.content.ContentResolver.query(ContentResolver.java:434)             at slimsimapps.troff.MainActivity.initialize(MainActivity.java:106)             at slimsimapps.troff.MainActivity.InitializeExternal(MainActivity.java:80)             at java.lang.reflect.Method.invoke(Native Method)             at android.view.View$DeclaredOnClickListener.onClick(View.java:4447)             at android.view.View.performClick(View.java:5198)             at android.view.View$PerformClick.run(View.java:21147)             at android.os.Handler.handleCallback(Handler.java:739)             at android.os.Handler.dispatchMessage(Handler.java:95)             at android.os.Looper.loop(Looper.java:148)             at android.app.ActivityThread.main(ActivityThread.java:5417)             at java.lang.reflect.Method.invoke(Native Method)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)     --------- beginning of system 

Answer 1

You have two solutions for your problem. The quick one is to lower targetApi to 22 (build.gradle file). Second is to use new and wonderful ask-for-permission model:

if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)         != PackageManager.PERMISSION_GRANTED) {      // Should we show an explanation?     if (shouldShowRequestPermissionRationale(             Manifest.permission.READ_EXTERNAL_STORAGE)) {         // Explain to the user why we need to read the contacts     }      requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},             MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);      // MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE is an     // app-defined int constant that should be quite unique      return; } 

Sniplet found here: https://developer.android.com/training/permissions/requesting.html

Solutions 2: If it does not work try this:

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M     && ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},         REQUEST_PERMISSION);  return; 

}

and then in callback

@Override public void onRequestPermissionsResult(final int requestCode, @NonNull final String[] permissions, @NonNull final int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); if (requestCode == REQUEST_PERMISSION) {     if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {         // Permission granted.     } else {         // User refused to grant permission.     } } } 

that is from comments. thanks