Android 读取外部存储出现 securityException

Android reading external storage gives securityException

我正在尝试获取设备中的音乐文件。这是我的工作:

public ArrayList<Track> getAllSongsFromSDCARD()
{
    allTracks = new ArrayList<Track>();
    String[] STAR = { "*" };
    Uri allsongsuri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    String selection = MediaStore.Audio.Media.IS_MUSIC + " != 0";

    Cursor cursor = mContext.getApplicationContext().getContentResolver().query(allsongsuri, STAR, selection, null, null);

    if (cursor != null) {
        if (cursor.moveToFirst()) {
            do {
                String song_name = cursor
                        .getString(cursor
                                .getColumnIndex(MediaStore.Audio.Media.DISPLAY_NAME));
                int song_id = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media._ID));

                String fullpath = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.DATA));


                String album_name = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ALBUM));
                int album_id = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));

                String artist_name = cursor.getString(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ARTIST));
                int artist_id = cursor.getInt(cursor
                        .getColumnIndex(MediaStore.Audio.Media.ARTIST_ID));



                String duration = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION));
                int[] splitTime = null;
                String hours, minutes, seconds, formattedTime;
                try{
                    splitTime = splitToComponentTimes(BigDecimal.valueOf(Long.valueOf(duration)/1000));
                    hours = String.valueOf(splitTime[0]);
                    minutes = String.valueOf(splitTime[1]);
                    seconds = String.valueOf(splitTime[2]);
                    if(hours.equals("0")){
                        formattedTime = minutes + ":" + seconds;
                    }else{
                        formattedTime = hours + ":" + minutes + ":" + seconds;
                    }
                }catch (Exception e){
                    formattedTime = "00:00";
                }

                allTracks.add(new Track(song_name, song_id, fullpath, album_name, album_id, artist_name, artist_id, formattedTime));
            } while (cursor.moveToNext());

        }

        sortTracksAlphabetically(allTracks);
        cursor.close();
    }
    return allTracks;
}

我的清单中有以下权限:

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

当我 运行 在具有 Android 版本 4.3 的设备上运行该代码时,它工作正常。但是当我 运行 它在具有 Android 版本 5.0.2 的设备上时它给出

"java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=5701, uid=10054 requires android.permission.READ_EXTERNAL_STORAGE"

谁能告诉我为什么?这是完整的堆栈跟踪:

02-14 19:25:52.812    5701-5701/com.yrazlik.musicplayer E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.yrazlik.musicplayer, PID: 5701
java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=5701, uid=10054 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()
        at android.os.Parcel.readException(Parcel.java:1540)
        at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:185)
        at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:137)
        at android.content.ContentProviderProxy.query(ContentProviderNative.java:420)
        at android.content.ContentResolver.query(ContentResolver.java:478)
        at android.content.ContentResolver.query(ContentResolver.java:422)
        at com.yrazlik.musicplayer.dialogs.AllSongsDialog.getAllSongsFromSDCARD(AllSongsDialog.java:74)
        at com.yrazlik.musicplayer.dialogs.AllSongsDialog.onCreate(AllSongsDialog.java:59)
        at android.app.Dialog.dispatchOnCreate(Dialog.java:373)
        at android.app.Dialog.show(Dialog.java:274)
        at com.yrazlik.musicplayer.fragments.PlaylistFragment.onClick(PlaylistFragment.java:86)
        at android.view.View.performClick(View.java:4756)
        at android.view.View$PerformClick.run(View.java:19749)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5221)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

谢谢。

And i have the following permissions in my manifest

经常,如果您在清单中有 <uses-permission> 个元素但仍然出现权限错误,那是因为这些元素在清单中的位置错误。他们需要是 <manifest> 的直接子代,作为 <application>.

的同龄人

But why there was no problem with my android 4.3 device but it is a problem in 5.0.2 device?

在 Android 4.4 之前,READ_EXTERNAL_STORAGE 不存在或未在普通设备上强制执行。

"CommonsWare" 在其他 link

上的一个很好的回答

现在没有得到您的许可很大的原因是因为您的项目的targetSdkVersion为23或更高,而您请求的权限是"dangerous"。在 Android 6.0 中,这包括:

ACCESS_COARSE_LOCATION
ACCESS_FINE_LOCATION
ADD_VOICEMAIL
BODY_SENSORS
CALL_PHONE
相机
GET_ACCOUNTS
PROCESS_OUTGOING_CALLS
READ_CALENDAR
READ_CALL_LOG
READ_CELL_BROADCASTS
READ_CONTACTS
READ_EXTERNAL_STORAGE
READ_PHONE_STATE
READ_SMS
RECEIVE_MMS
RECEIVE_SMS
RECEIVE_WAP_PUSH
RECORD_AUDIO
SEND_SMS
USE_SIP
WRITE_CALENDAR
WRITE_CALL_LOG WRITE_CONTACTS
WRITE_EXTERNAL_STORAGE

对于这些权限,您的 targetSdkVersion 23+ 应用不仅需要具有 <uses-permission> 元素,而且您还必须在运行时向 [=76= 上的用户请求这些权限] 6.0+ 设备,使用 checkSelfPermission() 和 requestPermissions() 等方法。

作为临时解决方法,将您的 targetSdkVersion 降低到 23 以下。

但是,最终,您将有一些理由希望您的 targetSdkVersion 为 23 或更高。届时,您将需要调整您的应用程序以使用新的运行时权限系统。 Android 6.0 预览版文档有一个专门介绍此主题的页面。

现在我将我的 targetSdkVersion 从 23 降级到 21 它的工作,但它是一个临时解决方案。