Jibin Joseph Jibin Joseph - 4 months ago 42
Android Question

Null pointer Exception on file- URI?

I am a beginner,In my app a capture button is there to capture an image using device camera,so I have used a method captureImage() on the click event of that button.When I click the button a null pointer exception is thrown.I could not understand how this happens Can anyone help? Thanks in advance!

capture button on on Create () method

photoButton.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
/*
Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(cameraIntent, CAMERA_REQUEST);*/
captureImage();
}
});


captureImage() method

private void captureImage() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);

fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);

intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);

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


Null pointer exception on this method

public Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}

/**
* returning image / video
*/
private static File getOutputMediaFile(int type) {

// External sdcard location
File mediaStorageDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
Config.IMAGE_DIRECTORY_NAME);

// Create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d(TAG, "Oops! Failed create "
+ Config.IMAGE_DIRECTORY_NAME + " directory");
return null;
}
}

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

return mediaFile;
}


Logcat

java.lang.NullPointerException: file
at android.net.Uri.fromFile(Uri.java:447)
at com.riafy.user.imagegallerydemo.MainActivity.getOutputMediaFileUri(MainActivity.java:235)
at com.riafy.user.imagegallerydemo.MainActivity.captureImage(MainActivity.java:97)
at com.riafy.user.imagegallerydemo.MainActivity.access$100(MainActivity.java:29)
at com.riafy.user.imagegallerydemo.MainActivity$2.onClick(MainActivity.java:68)
at android.view.View.performClick(View.java:4761)
at android.view.View$PerformClick.run(View.java:19767)
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:5312)
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:901)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:696)

Answer

getOutputMediaFile(type) returns null.

 public Uri getOutputMediaFileUri(int type) {
    return Uri.fromFile(getOutputMediaFile(type));
}

You are returning here:

// Create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
    if (!mediaStorageDir.mkdirs()) {
        Log.d(TAG, "Oops! Failed create "
                + Config.IMAGE_DIRECTORY_NAME + " directory");
        return null;
    }
}

Have you added the following permission

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

to your manifest?

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