Android : getting NullPointerException when creating a file to save image from camera intent in fragment

so i've been trying to start a really simple camera intent, so iv'e went through a turorial did all the functions but when i'm pressing the button i'm getting null pointer exception .

this is my code:

package vidas.shay.mobilebridgetask;

import android.app.Activity;
import android.app.Fragment;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.annotation.Nullable;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Switch;
import android.widget.Toast;

import java.io.File;
import java.text.SimpleDateFormat;
import java.util.Date;


/**
 * Created by pitsponet on 26/03/2015.
 */
public class userDetailesTopFragment extends Fragment implements     View.OnClickListener {

//text views
EditText firstNameTextView;
EditText lastNameTextView;
EditText emailTextView;
EditText phoneNumberTextView;
EditText adressTextView;
Button addImageButton;
Button addHobbiesButton;
Switch statusSwitch;
ImageView userProfileImageView;

Button findMyFriendsButton;
Button updateMyLocationButton;
Button usersListButton;

public static final int MEDIA_TYPE_IMAGE = 1;
public static final int MEDIA_TYPE_VIDEO = 2;
private static final int CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE = 100;
private static final int CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE = 200;

private Uri fileUri;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    View v = inflater.inflate(R.layout.user_detailes_top_fragment_layout, container, false);

    //v.findViewById(R.id.BT_addImageToProfile).setOnClickListener(this);

    addImageButton = (Button) v.findViewById(R.id.BT_addImageToProfile);

    addImageButton.setOnClickListener(this);

    return v;

}


@Override
public void onClick(View v) {
    Log.d("here", "here ?");

    if (v == addImageButton) {
        startCamera();
    }


}


private void startCamera() {
    // create Intent to take a picture and return control to the calling application
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);


    fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE); // create a file to save the image
    intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri); // set the image file name

    // start the image capture Intent
    startActivityForResult(intent, CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE);
}


public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQUEST_CODE) {
        if (resultCode == Activity.RESULT_OK) {
            // Image captured and saved to fileUri specified in the Intent
            Toast.makeText(getActivity(), "Image saved to:\n" +
                    data.getData(), Toast.LENGTH_LONG).show();
        } else if (resultCode == Activity.RESULT_CANCELED) {
            // User cancelled the image capture
        } else {
            // Image capture failed, advise user
        }
    }

    if (requestCode == CAPTURE_VIDEO_ACTIVITY_REQUEST_CODE) {
        if (resultCode == Activity.RESULT_OK) {
            // Video captured and saved to fileUri specified in the Intent
            Toast.makeText(getActivity(), "Video saved to:\n" + data.getData(), Toast.LENGTH_LONG).show();
            //Toast.makeText(getActivity(),"Text!",Toast.LENGTH_SHORT).show();
        } else if (resultCode == Activity.RESULT_CANCELED) {
            // User cancelled the video capture
        } else {
            // Video capture failed, advise user
        }
    }
}


/**
 * Create a file Uri for saving an image or video
 */
private static Uri getOutputMediaFileUri(int type) {
    return Uri.fromFile(getOutputMediaFile(type));
}

/**
 * Create a File for saving an image or video
 */
private static File getOutputMediaFile(int type) {
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this.

    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
            Environment.DIRECTORY_PICTURES), "MyCameraApp");
    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            Log.d("MyCameraApp", "failed to create directory");
            return null;
        }
    }

    // Create a media file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == MEDIA_TYPE_IMAGE) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "IMG_" + timeStamp + ".jpg");
    } else if (type == MEDIA_TYPE_VIDEO) {
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
                "VID_" + timeStamp + ".mp4");
    } else {
        return null;
    }

    return mediaFile;
}


}

this is the error i'm getting >

03-27 15:13:28.620    3042-3042/vidas.shay.mobilebridgetask E/AndroidRuntime﹕     FATAL EXCEPTION: main
Process: vidas.shay.mobilebridgetask, PID: 3042
java.lang.NullPointerException: file
        at android.net.Uri.fromFile(Uri.java:447)
        at vidas.shay.mobilebridgetask.userDetailesTopFragment.getOutputMediaFileUri(userDetailesTopFragment.java:130)
        at vidas.shay.mobilebridgetask.userDetailesTopFragment.startCamera(userDetailesTopFragment.java:87)
        at vidas.shay.mobilebridgetask.userDetailesTopFragment.onClick(userDetailesTopFragment.java:75)
        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)

please can you help me fix this ?