CODEWITHSUNDEEP
javaandroiddirectory
Harsha
Harsha

Reputation: 23

Application crashes when i try to access phone's external memory

I have created a simple application which tries to access a phone's external storage files and display it on an alert box the code goes something like this.

btnShowDeviceFolders.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {
            CharSequence items[];

            final List<String> list = new ArrayList<String>();
            final File path =
                    Environment.getExternalStoragePublicDirectory
                            (
                                    //Environment.DIRECTORY_PICTURES
                                    Environment.DIRECTORY_DCIM
                                    //File.separator +"/"
                            );
            if(!path.exists())
            {
                //path.mkdirs();
             System.out.println("No file found");
            }
            String[] files = path.list();
            if (files.length == 0) {
                //System.out.println("The directory is empty");

            } else {
                for (String aFile : files) {

                    //System.out.println(aFile);
                    list.add(aFile);
                }
            }
            items = files;

            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setTitle("Select Project Folder");
            builder.setItems(items, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int item) {

                    Toast.makeText(getApplicationContext(),list.get(item),Toast.LENGTH_LONG).show();
                                        }
            });
            builder.show();
        }
    });

But this code works fine on the emulator it lists me the folders that are present, but when i build the apk and test it on my mobile it crashes(I'm using android Oreo for testing). The Stacktrace does not give any errors enter image description here What can I do to overcome this issue.

Upvotes: 0

Views: 221

Answers (3)

user9683713
user9683713

Reputation: 185

Give permission for external memory in the android_manifest.xml file.

Upvotes: 1

pooja majoka
pooja majoka

Reputation: 136

You are only giving permission in manifest that is not sufficient you need to give runtime permission .

 if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            //Show Information about why you need the permission
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setTitle("Need Storage Permission");
            builder.setMessage("This app needs storage permission.");
            builder.setPositiveButton("Grant", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                    ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, EXTERNAL_STORAGE_PERMISSION_CONSTANT);
                }
            });
            builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });
            builder.show();
        } else if (permissionStatus.getBoolean(Manifest.permission.WRITE_EXTERNAL_STORAGE,false)) {
            //Previously Permission Request was cancelled with 'Dont Ask Again',
            // Redirect to Settings after showing Information about why you need the permission
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setTitle("Need Storage Permission");
            builder.setMessage("This app needs storage permission.");
            builder.setPositiveButton("Grant", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                    sentToSettings = true;
                    Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                    Uri uri = Uri.fromParts("package", getPackageName(), null);
                    intent.setData(uri);
                    startActivityForResult(intent, REQUEST_PERMISSION_SETTING);
                    Toast.makeText(getBaseContext(), "Go to Permissions to Grant Storage", Toast.LENGTH_LONG).show();
                }
            });
            builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });
            builder.show();
        } else {
            //just request the permission
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, EXTERNAL_STORAGE_PERMISSION_CONSTANT);
        }

        SharedPreferences.Editor editor = permissionStatus.edit();
        editor.putBoolean(Manifest.permission.WRITE_EXTERNAL_STORAGE,true);
        editor.commit();


    } else {
        //You already have the permission, just go ahead.
        proceedAfterPermission();
    }

Upvotes: 0

Umer Farooq
Umer Farooq

Reputation: 180

You have to give android.permission.READ_EXTERNAL_STORAGE run time. here is the tutorial

Upvotes: 0

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