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私はアンドロイドの開発には初めてです。私はクリック時に画像をキャプチャするボタンを持っています。ボタンをクリックすると、nullポインタ例外エラーがスローされます。ここでアンドロイド - ヌルポインタファイルURI上の例外
が、私はディレクトリを作成するために、マニフェストファイルにアクセス権を追加しました私の主な活動方法
btnCapturePicture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
captureImage();
}
});
/**
Record video button click event
*/
btnRecordVideo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// record video
recordVideo();
}
});
// Checking camera availability
if (!isDeviceSupportCamera()) {
Toast.makeText(getApplicationContext(),
"Sorry! Your device doesn't support camera",
Toast.LENGTH_LONG).show();
// will close the app if the device does't have camera
finish();
}
}
/**
checking device has camera hardware or not
*/
private boolean isDeviceSupportCamera() {
if (getApplicationContext().getPackageManager().hasSystemFeature(
PackageManager.FEATURE_CAMERA)) {
// this device has a camera
return true;
} else {
// no camera on this device
return false;
}
}
/**
* Launching camera app to capture image
*/
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_CAPTURE_IMAGE_REQUEST_CODE);
}
/**
* Launching camera app to record video
*/
private void recordVideo() {
Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
fileUri = getOutputMediaFileUri(MEDIA_TYPE_VIDEO);
// set video quality
intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 1);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);// set the image file
// name
// start the video capture Intent
startActivityForResult(intent, CAMERA_CAPTURE_VIDEO_REQUEST_CODE);
}
/**
* Here we store the file url as it will be null after returning from camera
* app
*/
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// save file url in bundle as it will be null on screen orientation
// changes
outState.putParcelable("file_uri", fileUri);
}
@Override
protected void onRestoreInstanceState (Bundle savedInstanceState){
super.onRestoreInstanceState(savedInstanceState);
// get the file url
fileUri = savedInstanceState.getParcelable("file_uri");
}
/**
* Receiving activity result method will be called after closing the camera
* */
@Override
protected void onActivityResult (int requestCode, int resultCode, Intent data){
// if the result is capturing Image
if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
// successfully captured the image
// launching upload activity
launchUploadActivity(true);
} else if (resultCode == RESULT_CANCELED) {
// user cancelled Image capture
Toast.makeText(getApplicationContext(),
"Sorry! Failed to capture image", Toast.LENGTH_SHORT).show();
}
} else if (requestCode == CAMERA_CAPTURE_VIDEO_REQUEST_CODE) {
if (resultCode == RESULT_OK) {
// video successfully recorded
//launching upload activity
launchUploadActivity(false);
} else if (resultCode == RESULT_CANCELED) {
// user cancelled recording
Toast.makeText(getApplicationContext(), "Sorry! Failed to record video", Toast.LENGTH_SHORT).show();
}
}
}
private void launchUploadActivity(boolean isImage){
Intent i = new Intent(MainActivity.this, UploadActivity.class);
i.putExtra("filePath", fileUri.getPath());
i.putExtra("isImage", isImage);
startActivity(i);
}
/**
* Creating file uri to store image/video
*/
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 if (type == MEDIA_TYPE_VIDEO) {
mediaFile = new File(mediaStorageDir.getPath() + File.separator+ "VID_" + timeStamp + ".mp4");
} else {
return null;
}
return mediaFile;
}
}
であるここに私のManifest.xmlファイルがある
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="11"
android:targetSdkVersion="23" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />
マイデバッガのエラーメッセージは、この
ですProcess: com.example.sathwik.uploadtrail1, PID: 2406
java.lang.NullPointerException: file
at android.net.Uri.fromFile(Uri.java:452)
at com.example.sathwik.uploadtrail1.MainActivity.getOutputMediaFileUri(MainActivity.java:163)
at com.example.sathwik.uploadtrail1.MainActivity.captureImage(MainActivity.java:90)
at com.example.sathwik.uploadtrail1.MainActivity.access$000(MainActivity.java:21)
at com.example.sathwik.uploadtrail1.MainActivity$1.onClick(MainActivity.java:50)
は 'getOutputMediaFile（int型）' '戻っnull'なのでように見えます。デバッガを使用して、なぜ – Jens