java.io.filenotfoundexception open failed eacces (

Question

The following code which consists of downloading a file from a server and save it in the storage works fine when the device has an internal storage.
But when I tried it with a device with no internal storage, only with external storage I get the following exception.

java.io.filenotfoundexception open failed eacces (permission denied)

public void downloadFile(String dlUrl, String dlName) {
    int count;

    HttpURLConnection con = null;
    InputStream is = null;
    FileOutputStream fos = null;

    try {
        URL url = new URL( dlUrl );
        con = (HttpURLConnection) url.openConnection();
        con.setDoInput(true);
        con.connect();

        is = url.openStream();
        String dir = Environment.getExternalStorageDirectory() + Util.DL_DIRECTORY;
        File file = new File( dir );
        if( !file.exists() ){
            file.mkdir();
        }

        Util.LOG_W(TAG, "Downloading: " + dlName + " ...");

        fos = new FileOutputStream(file + "/" +  dlName);
        byte data[] = new byte[1024];

        while( (count = is.read(data)) != -1 ){
            fos.write(data, 0, count);
        }

        Util.LOG_D(TAG, dlName + " Download Complete!");


    } catch (Exception e) {
        Util.LOG_E(TAG, "DOWNLOAD ERROR = " + e.toString() );
        bServiceDownloading = false;
    }
    finally{
        try {
            if( is != null)
                is.close();
            if( fos != null)
                fos.close();
            if( con != null)
                con.disconnect();
        } catch (Exception e) {
            Util.LOG_E(TAG, "CLOSE ERROR = " + e.toString() );
        }
    }
}

And in manifest file I has the following:

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

Any suggestions what maybe the cause? By the way Environment.getExternalStorageDirectory() returns /mnt/sdcard/ and file.mkdir() return false.

Answer 1

I suspect you are running Android 6.0 Marshmallow (API 23) or later. If this is the case, you must implement runtime permissions before you try to read/write external storage. https://developer.android.com/training/permissions/requesting.html

Answer 2

Try using mkdirs instead of mkdir. If you are creating a directory path and parent doesn't exist then you should use mkdirs.

Answer 3

This problem seems to be caused by several factors.

Check#1
First add this permission in your manifest file and check if it is working:

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

</application>

　　.....

Check#2:

If you are running on an emulator, check the properties to see if it has an SD card.

Check#3:

Disable file transfer from device to computer. If Enabled, the app wont be able to access the SD card.

Check#4:
If still not working, try the following:

 String dir = Environment.getExternalStorageDirectory().getAbsolutePath()

For me the following worked:
The problem is that getExternalStorageDirectory returns /mnt/sdcard whereas I need the actual path of external storage which is /mnt/sdcard-ext and there is no API in android that can get me the absolute path of removable sdcard.
My solution was to hard code the directory as follows:

String dir = "/mnt/sdcard-ext" ;

Since the application is intended to work only on one device, the above did the job.
If you encounter the same problem, use an file explorer application to find out the name of the external directory and hard code it.

Answer 4

try
Environment.getExternalStorageDirectory().getAbsolutePath()

and don't forget to add

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

Answer 5

i have done very silly mistake. I have already put in AndroidManifest.xml

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

and also add permission in java file,as get permission pragmatically. But there is mistake of Manifest.permission.READ_EXTERNAL_STORAGE. Please use Manifest.permission.WRITE_EXTERNAL_STORAGE.

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