Why Getexternalfilesdirs() Doesn't Work On Some Devices?

My app runs on Android 5.0. I use method getExternalFilesDirs() to check if external SD card is available. If it returns more than 1 File, that means external SD card exists. But

Solution 1:

For getExternalFilesDirs to return the path of the sdcard, the OEM must have set the SECONDARY_STORAGE environment variable in the device specific init.rc file as mentioned here: https://source.android.com/devices/storage/config-example.html

Look at the source of getExternalFilesDirs here: http://androidxref.com/5.1.1_r6/xref/frameworks/base/core/java/android/app/ContextImpl.java#1039

The value is obtained from Environment.buildExternalStorageAppFilesDirs. Look at that source here: http://androidxref.com/5.1.1_r6/xref/frameworks/base/core/java/android/os/Environment.java#206

The value is dependent on mExternalDirsForApp, which in turn is populated by reading the contents of SECONDARY_STORAGE variable: http://androidxref.com/5.1.1_r6/xref/frameworks/base/core/java/android/os/Environment.java#136

As you can see, if the SECONDARY_STORAGE variable is not set, the sdcard path will not be returned. You can cross-check this by going to adb shell and looking at the output of echo $SECONDARY_STORAGE

Solution 2:

In my projects using this code & i don't have any problem.

method of getExternalFilesDirs return array with 2 length.

Dirs[0] ==> Internal Sorage Dirs[1] ==> External Storage

 File[] Dirs = ContextCompat.getExternalFilesDirs(MyApp.GetContext(), null);

Solution 3:

this issue there is in some of Lenovo device too.

my solution is this.

String EXTERNAL_SD_PATH1;
String EXTERNAL_SD_PATH2;

publicbooleanhasExternalSDCard()
{
    try
    {
        Stringstate= Environment.getExternalStorageState();
        if(Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state))
        returntrue;
    }
    catch (Throwable e)
    {}

    returnfalse;
}

        @SuppressLint("SdCardPath")protectedsynchronizedvoid_prepareStorage()
        {
            EXTERNAL_SD_PATH1 = null;
            EXTERNAL_SD_PATH2 = null;
            if (hasExternalSDCard())
            {
                try
                {
                    if(VERSION_SDK_INT > 18)
                    {
                        Contextcontext= getContext();
                        File[]  sds = getExternalFilesDirs("");

                        if(sds == null)
                            return;

                        if(sds.length >= 2)
                        {
                            EXTERNAL_SD_PATH1 = TextWorker.getSubStringBeforeLastMark(sds[1].getAbsolutePath(),"/Android/");
                            if(sds.length > 2)
                                EXTERNAL_SD_PATH2 = TextWorker.getSubStringBeforeLastMark(sds[2].getAbsolutePath(),"/Android/");
                        }
                        else
                        {
                            Stringinternal= sds[0].getAbsolutePath();
                            internal = TextWorker.getSubStringBeforeLastMark(internal,"/Android/");
                            intlen= internal.length();
                            intnum= Integer.valueOf(internal.substring(len - 1));

                            Stringex1= internal.substring(0, len-1) + (num+1);
                            Filesd1=newFile(ex1);
                            if(sd1.exists())
                                EXTERNAL_SD_PATH1 = sd1.getAbsolutePath();

                            Stringex2= internal.substring(0, len-1) + (num+2);
                            Filesd2=newFile(ex2);
                            if(sd2.exists())
                                EXTERNAL_SD_PATH2 = sd2.getAbsolutePath();
                        }
                    }

                    else
                    {
                        Filesd= Environment.getExternalStorageDirectory();
                        Stringpath= sd.getAbsolutePath();
                        if (sd.exists() && (path.contains("/mnt/") || path.contains("/storage") || path.contains("/sdcard")) && (!path.contains("emulate")))
                        {
                            EXTERNAL_SD_PATH1 = path;
                        }
                    }
                }
                catch (Throwable e)
                {}
            }

        }


        publicstatic String getSubStringBeforeLastMark(String str,String mark)
    { 
        intl= str.lastIndexOf(mark);
        if(l == -1 || l == 0)
            return"";

        return str.substring(0, l);
    }