java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.io.File.exists()' on a null object reference

Issue

Hello everyone, I try to access the storage and select an image immediately after the app crashes me and then I get the following error:

It is important to note API 29 everything works great and only when I upload the API to version 30-31 I get this error. I have all the storage permissions

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.pets.igloopet, PID: 9797
java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.io.File.exists()' on a null object reference
    at com.pets.igloopet.activity.addpet.AddImage$1.onClick(AddImage.java:149)
    at com.cocosw.bottomsheet.BottomSheet$4.onItemClick(BottomSheet.java:332)
    at android.widget.AdapterView.performItemClick(AdapterView.java:330)
    at android.widget.AbsListView.performItemClick(AbsListView.java:1197)
    at android.widget.AbsListView$PerformClick.run(AbsListView.java:3190)
    at android.widget.AbsListView$3.run(AbsListView.java:4166)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:201)
    at android.os.Looper.loop(Looper.java:288)
    at android.app.ActivityThread.main(ActivityThread.java:7839)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)

This is my code (File Addimage.java):

        builder.listener(new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            switch (which) {
                case R.id.camera_cards:
                    if (ProjectUtils.hasPermissionInManifest(getActivity(), PICK_FROM_CAMERA, Manifest.permission.CAMERA)) {
                        if (ProjectUtils.hasPermissionInManifest(getActivity(), PICK_FROM_GALLERY, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                            try {
                                Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                            File file = getOutputMediaFile(1);
                               
                                if (!file.exists()) {
                                    try {
                                        ProjectUtils.pauseProgressDialog();
                                        file.createNewFile();
                                    } catch (IOException e) {
                                        e.printStackTrace();
                                    }
                                }
                                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                                    //Uri contentUri = FileProvider.getUriForFile(getApplicationContext(), "com.example.asd", newFile);
                                    picUri = FileProvider.getUriForFile(getActivity().getApplicationContext(), getActivity().getApplicationContext().getPackageName() + ".fileprovider", file);
                                } else {
                                    picUri = Uri.fromFile(file); // create
                                }

                                sharedPrefrence.setValue(Consts.IMAGE_URI_CAMERA, picUri.toString());
                                intent.putExtra(MediaStore.EXTRA_OUTPUT, picUri); // set the image file
                                startActivityForResult(intent, PICK_FROM_CAMERA);
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                    }

                    break;
                case R.id.gallery_cards:
                    if (ProjectUtils.hasPermissionInManifest(getActivity(), PICK_FROM_CAMERA, Manifest.permission.CAMERA)) {
                        if (ProjectUtils.hasPermissionInManifest(getActivity(), PICK_FROM_GALLERY, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {


                         File file = getOutputMediaFile(1);

                            if (!file.exists()) {

                                try {
                                    file.createNewFile();
                                } catch (IOException e) {
                                    e.printStackTrace();
                                }

                            }


                            picUri = Uri.fromFile(file);

                            Intent intent = new Intent();
                            intent.setType("image/*");
                            intent.setAction(Intent.ACTION_GET_CONTENT);
                            startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_FROM_GALLERY);

                        }
                    }
                    break;
                case R.id.cancel_cards:
                    builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
                        @Override
                        public void onDismiss(DialogInterface dialog) {
                            dialog.dismiss();
                        }
                    });
                    break;
            }
        }
    });

Solution

you get this exception because the method "getOutputMediaFile" return null and you try to use null object.

first, add null check to file, its always good approach.

second, you have to understand why this method return null and not the file you want. if you try to use "getExternalStorageDirectory" and call mkdirs(), its depracated, you should use "getExternalFilesDir" on your context/activity.

try to do the change, if it does not help, please share with us the method "getOutputMediaFile" so we can see whats going on there and give you further help.

Answered By - Bardak