Develop Reference

java.io.FileNotFoundException: No content provider:

i have problem to reproduce a video with videoView.setVideoPath();
in fact video doesn't reproduce..i don't know why. Video's path is correct.
This is my code:
public class MainActivity extends AppCompatActivity {
private VideoView videoView;
private int position = 0;
private MediaController mediaController;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
videoView = (VideoView) findViewById(R.id.videoView);
// Set the media controller buttons
if (mediaController == null) {
mediaController = new MediaController(MainActivity.this);
// Set the videoView that acts as the anchor for the MediaController.
mediaController.setAnchorView(videoView);
// Set MediaController for VideoView
videoView.setMediaController(mediaController);
}
try {
// ID of video file.
String videoUrl="https://www.youtube.com/watch?v=JHdmkP-nfsA";
videoView.setVideoPath(videoUrl);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
videoView.requestFocus();
// When the video file ready for playback.
videoView.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mediaPlayer) {
videoView.seekTo(position);
if (position == 0) {
videoView.start();
}
// When video Screen change size.
mediaPlayer.setOnVideoSizeChangedListener(new MediaPlayer.OnVideoSizeChangedListener() {
#Override
public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
// Re-Set the videoView that acts as the anchor for the MediaController
mediaController.setAnchorView(videoView);
}
});
}
});
}
}
Who can help me?
Thanks in advance everybody!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
LOGCAT:
Couldn't open https://www.youtube.com/watch?v=JHdmkP-nfsA: java.io.FileNotFoundException: No content provider: https://www.youtube.com/watch?v=JHdmkP-nfsA
10-29 12:27:28.419 25932-25932/com.example.marco.ud D/MediaPlayer: setDataSource IOException | SecurityException happend :
java.io.FileNotFoundException: No content provider: https://www.youtube.com/watch?v=JHdmkP-nfsA
at android.content.ContentResolver.openTypedAssetFileDescriptor(ContentResolver.java:1137)
at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:988)
at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:911)
at android.media.MediaPlayer.attemptDataSource(MediaPlayer.java:1102)
at android.media.MediaPlayer.setDataSource(MediaPlayer.java:1093)
at android.widget.VideoView.openVideo(VideoView.java:356)
at android.widget.VideoView.-wrap0(VideoView.java)
at android.widget.VideoView$7.surfaceCreated(VideoView.java:632)
at android.view.SurfaceView.updateWindow(SurfaceView.java:656)
at android.view.SurfaceView$3.onPreDraw(SurfaceView.java:172)
at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:1013)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2510)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1519)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:7113)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:927)
at android.view.Choreographer.doCallbacks(Choreographer.java:702)
at android.view.Choreographer.doFrame(Choreographer.java:638)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:913)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6780)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1496)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1386)

You can not play a YouTube video directly to the VideoView or ExoPlayer, for that, first you have to download the video then set the locale path of that video to the method VideoView.setVideoPath("path")
If you want to play only YouTube videos then use YouTube Android Player API, and if you only want to play other remote videos (.mp4, .ogg, .3gp etc.) then use the method VideoView.setVideoURI("uri").
Example-
String videoUrl = "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4";
try {
// Start the MediaController
MediaController mediacontroller = new MediaController(this);
mediacontroller.setAnchorView(videoview);
// Get the URL from String videoUrl
Uri video = Uri.parse(videoUrl);
videoview.setMediaController(mediacontroller);
videoview.setVideoURI(video);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
videoview.setOnPreparedListener(new OnPreparedListener() {
public void onPrepared(MediaPlayer mp) {
videoview.start();
}
});

I recommend using ExoPlayer instead of VideoView:
app gradle:
implementation 'com.google.android.exoplayer:exoplayer:2.10.8'
layout xml:
<com.google.android.exoplayer2.ui.PlayerView
android:id="#+id/video_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_centerInParent="true" />
java code:
PlayerView videoView = findViewById(R.id.video_view);
SimpleExoPlayer player = ExoPlayerFactory.newSimpleInstance(this);
videoView.setPlayer(player);
// Produces DataSource instances through which media data is loaded.
DataSource.Factory dataSourceFactory = new DefaultDataSourceFactory(this, Util.getUserAgent(this, "yourApplicationName"));
// This is the MediaSource representing the media to be played.
MediaSource videoSource = new ProgressiveMediaSource.Factory(dataSourceFactory).createMediaSource(Uri.parse(fileEntity.getPath()));
// Prepare the player with the source.
player.prepare(videoSource);
player.setPlayWhenReady(true);

VideoView.setVideoPath requires a local path on the device. You should try setVideoURI instead if you want to play a remote MP4 or something else. VideoView Documentation
If you want to embed YouTube videos in your app, consider using the YouTube Android Player API or using something like a WebView

I had same issue but it was because of corporate proxy server. I used same app over my mobile internet and it started working. Hope it save someone's time

You are using VideoView which
Displays a video file. The VideoView class can load images from
various sources (such as resources or content providers).
You might want to try setVideoURI
Or : ExoPlayer if min SDK > 16
Or use SurfaceView :
SurfaceView surfaceView = (SurfaceView)findViewById(R.id.surfaceView);
SurfaceHolder surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(new SurfaceHolder.Callback() {
#Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
mediaPlayer.setDataSource(STREAM_URL);
mediaPlayer.setDisplay(surfaceHolder);
mediaPlayer.start();
}
Ref : https://developer.android.com/reference/android/widget/VideoView.html

Adding OnClickListener makes app crash

I'm working on a term project and I'm new to java and android app development. I have experience in other programming languages, though. I'm trying to reverse engineer an app to make it able to connect and send data via bluetooth. I want to make a list with all the available bluetooth devices, a button to turn on/off bluetooth, one for making the phone discoverable for other devices and another to search for unpaired devices. But every time I add an OnClickListener to the onCreate method, the app crashes before it opens. Could anyone help me out?
The source code for the app I am trying to modify can be found here:
https://github.com/pazaan/600SeriesAndroidUploader
Here is the part that seems to makes it crash:
lvNewDevices.setOnItemClickListener(MainActivity.this);
btnONOFF.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d(TAG, "onClick: enabling/disabling bluetooth.");
enableDisableBT();
}
});
btnStartConnection.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startConnection();
}
});
btnSend.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
byte[] bytes = etSend.getText().toString().getBytes(Charset.defaultCharset());
mBluetoothConnection.write(bytes);
}
});
And here is all of OnCreate:
#Override
public void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "onCreate called");
super.onCreate(savedInstanceState);
Button btnONOFF = (Button) findViewById(R.id.btnONOFF);
btnEnableDisable_Discoverable = (Button) findViewById(R.id.btnDiscoverable_on_off);
lvNewDevices = (ListView) findViewById(R.id.lvNewDevices);
mBTDevices = new ArrayList<>();
btnStartConnection = (Button) findViewById(R.id.btnStartConnection);
//Broadcasts when bond state changes (ie:pairing)
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
registerReceiver(mBroadcastReceiver4, filter);
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
//FUCKUP:
lvNewDevices.setOnItemClickListener(MainActivity.this);
btnONOFF.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.d(TAG, "onClick: enabling/disabling bluetooth.");
enableDisableBT();
}
});
btnStartConnection.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
startConnection();
}
});
btnSend.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
byte[] bytes = etSend.getText().toString().getBytes(Charset.defaultCharset());
mBluetoothConnection.write(bytes);
}
});
mRealm = Realm.getDefaultInstance();
RealmResults<PumpStatusEvent> data = mRealm.where(PumpStatusEvent.class)
.findAllSorted("eventDate", Sort.DESCENDING);
if (data.size() > 0)
dataStore.setLastPumpStatus(data.first());
setContentView(R.layout.activity_main);
PreferenceManager.getDefaultSharedPreferences(getBaseContext()).registerOnSharedPreferenceChangeListener(this);
prefs = PreferenceManager.getDefaultSharedPreferences(getBaseContext());
if (!prefs.getBoolean(getString(R.string.preference_eula_accepted), false)) {
stopCgmService();
}
// setup preferences
configurationStore.setPollInterval(Long.parseLong(prefs.getString("pollInterval", Long.toString(MedtronicCnlIntentService.POLL_PERIOD_MS))));
configurationStore.setLowBatteryPollInterval(Long.parseLong(prefs.getString("lowBatPollInterval", Long.toString(MedtronicCnlIntentService.LOW_BATTERY_POLL_PERIOD_MS))));
configurationStore.setReducePollOnPumpAway(prefs.getBoolean("doublePollOnPumpAway", false));
chartZoom = Integer.parseInt(prefs.getString("chartZoom", "3"));
configurationStore.setMmolxl(prefs.getBoolean("mmolxl", false));
configurationStore.setMmolxlDecimals(prefs.getBoolean("mmolDecimals", false));
// Disable battery optimization to avoid missing values on 6.0+
// taken from https://github.com/NightscoutFoundation/xDrip/blob/master/app/src/main/java/com/eveningoutpost/dexdrip/Home.java#L277L298
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
final String packageName = getPackageName();
final PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
if (!pm.isIgnoringBatteryOptimizations(packageName)) {
Log.d(TAG, "Requesting ignore battery optimization");
try {
// ignoring battery optimizations required for constant connection
// to peripheral device - eg CGM transmitter.
final Intent intent = new Intent();
intent.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
intent.setData(Uri.parse("package:" + packageName));
startActivity(intent);
} catch (ActivityNotFoundException e) {
Log.d(TAG, "Device does not appear to support battery optimization whitelisting!");
}
}
}
LocalBroadcastManager.getInstance(this).registerReceiver(
statusMessageReceiver,
new IntentFilter(MedtronicCnlIntentService.Constants.ACTION_STATUS_MESSAGE));
LocalBroadcastManager.getInstance(this).registerReceiver(
new UpdatePumpReceiver(),
new IntentFilter(MedtronicCnlIntentService.Constants.ACTION_UPDATE_PUMP));
mEnableCgmService = Eula.show(this, prefs);
IntentFilter batteryIntentFilter = new IntentFilter();
batteryIntentFilter.addAction(Intent.ACTION_BATTERY_LOW);
batteryIntentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
batteryIntentFilter.addAction(Intent.ACTION_BATTERY_OKAY);
registerReceiver(batteryReceiver, batteryIntentFilter);
IntentFilter usbIntentFilter = new IntentFilter();
usbIntentFilter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
usbIntentFilter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
usbIntentFilter.addAction(MedtronicCnlIntentService.Constants.ACTION_USB_PERMISSION);
registerReceiver(usbReceiver, usbIntentFilter);
LocalBroadcastManager.getInstance(this).registerReceiver(
usbReceiver,
new IntentFilter(MedtronicCnlIntentService.Constants.ACTION_NO_USB_PERMISSION));
LocalBroadcastManager.getInstance(this).registerReceiver(
usbReceiver,
new IntentFilter(MedtronicCnlIntentService.Constants.ACTION_USB_REGISTER));
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
if (toolbar != null) {
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(false);
getSupportActionBar().setElevation(0);
getSupportActionBar().setTitle("Nightscout");
}
final PrimaryDrawerItem itemSettings = new PrimaryDrawerItem()
.withName("Settings")
.withIcon(GoogleMaterial.Icon.gmd_settings)
.withSelectable(false);
final PrimaryDrawerItem itemRegisterUsb = new PrimaryDrawerItem()
.withName("Registered devices")
.withIcon(GoogleMaterial.Icon.gmd_usb)
.withSelectable(false);
final PrimaryDrawerItem itemStopCollecting = new PrimaryDrawerItem()
.withName("Stop collecting data")
.withIcon(GoogleMaterial.Icon.gmd_power_settings_new)
.withSelectable(false);
final PrimaryDrawerItem itemGetNow = new PrimaryDrawerItem()
.withName("Read data now")
.withIcon(GoogleMaterial.Icon.gmd_refresh)
.withSelectable(false);
final PrimaryDrawerItem itemUpdateProfile = new PrimaryDrawerItem()
.withName("Update pump profile")
.withIcon(GoogleMaterial.Icon.gmd_insert_chart)
.withSelectable(false);
final PrimaryDrawerItem itemClearLog = new PrimaryDrawerItem()
.withName("Clear log")
.withIcon(GoogleMaterial.Icon.gmd_clear_all)
.withSelectable(false);
final PrimaryDrawerItem itemCheckForUpdate = new PrimaryDrawerItem()
.withName("Check for App update")
.withIcon(GoogleMaterial.Icon.gmd_update)
.withSelectable(false);
assert toolbar != null;
new DrawerBuilder()
.withActivity(this)
.withAccountHeader(new AccountHeaderBuilder()
.withActivity(this)
.withHeaderBackground(R.drawable.drawer_header)
.build()
)
.withTranslucentStatusBar(false)
.withToolbar(toolbar)
.withActionBarDrawerToggle(true)
.withSelectedItem(-1)
.addDrawerItems(
itemSettings,
//itemUpdateProfile, // TODO - re-add when we to add Basal Profile Upload
itemRegisterUsb,
itemCheckForUpdate,
itemClearLog,
itemGetNow,
itemStopCollecting
)
.withOnDrawerItemClickListener(new Drawer.OnDrawerItemClickListener() {
#Override
public boolean onItemClick(View view, int position, IDrawerItem drawerItem) {
if (drawerItem.equals(itemSettings)) {
openSettings();
} else if (drawerItem.equals(itemRegisterUsb)) {
openUsbRegistration();
} else if (drawerItem.equals(itemStopCollecting)) {
mEnableCgmService = false;
stopCgmService();
finish();
} else if (drawerItem.equals(itemGetNow)) {
// It was triggered by user so start reading of data now and not based on last poll.
sendStatus("Requesting poll now...");
startCgmService(System.currentTimeMillis() + 1000);
} else if (drawerItem.equals(itemClearLog)) {
clearLogText();
} else if (drawerItem.equals(itemCheckForUpdate)) {
checkForUpdateNow();
}
return false;
}
})
.build();
mTextViewLog = (TextView) findViewById(R.id.textview_log);
mScrollView = (ScrollView) findViewById(R.id.scrollView);
mScrollView.setSmoothScrollingEnabled(true);
mChart = (GraphView) findViewById(R.id.chart);
// disable scrolling at the moment
mChart.getViewport().setScalable(false);
mChart.getViewport().setScrollable(false);
mChart.getViewport().setYAxisBoundsManual(true);
mChart.getViewport().setMinY(80);
mChart.getViewport().setMaxY(120);
mChart.getViewport().setXAxisBoundsManual(true);
final long now = System.currentTimeMillis(),
left = now - chartZoom * 60 * 60 * 1000;
mChart.getViewport().setMaxX(now);
mChart.getViewport().setMinX(left);
// due to bug in GraphView v4.2.1 using setNumHorizontalLabels reverted to using v4.0.1 and setOnXAxisBoundsChangedListener is n/a in this version
/*
mChart.getViewport().setOnXAxisBoundsChangedListener(new Viewport.OnXAxisBoundsChangedListener() {
#Override
public void onXAxisBoundsChanged(double minX, double maxX, Reason reason) {
double rightX = mChart.getSeries().get(0).getHighestValueX();
hasZoomedChart = (rightX != maxX || rightX - chartZoom * 60 * 60 * 1000 != minX);
}
});
*/
mChart.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
if (!mChart.getSeries().isEmpty() && !mChart.getSeries().get(0).isEmpty()) {
double rightX = mChart.getSeries().get(0).getHighestValueX();
mChart.getViewport().setMaxX(rightX);
mChart.getViewport().setMinX(rightX - chartZoom * 60 * 60 * 1000);
}
hasZoomedChart = false;
return true;
}
});
mChart.getGridLabelRenderer().setNumHorizontalLabels(6);
// due to bug in GraphView v4.2.1 using setNumHorizontalLabels reverted to using v4.0.1 and setHumanRounding is n/a in this version
// mChart.getGridLabelRenderer().setHumanRounding(false);
mChart.getGridLabelRenderer().setLabelFormatter(
new DefaultLabelFormatter() {
DateFormat mFormat = new SimpleDateFormat("HH:mm", Locale.US); // 24 hour format forced to fix label overlap
#Override
public String formatLabel(double value, boolean isValueX) {
if (isValueX) {
return mFormat.format(new Date((long) value));
} else {
return MainActivity.strFormatSGV(value);
}
}
}
);
}
Here is the logcat output:
09-26 12:38:19.826 6324-6324/? I/art: Late-enabling -Xcheck:jni
09-26 12:38:20.157 6324-6324/info.nightscout.android E/Fabric: Failure onPreExecute()
java.lang.IllegalArgumentException: Fabric could not be initialized, API key missing from AndroidManifest.xml. Add the following tag to your Application element
<meta-data android:name="io.fabric.ApiKey" android:value="YOUR_API_KEY"/>
at io.fabric.sdk.android.services.common.ApiKey.logErrorOrThrowException(ApiKey.java:110)
at io.fabric.sdk.android.services.common.ApiKey.getValue(ApiKey.java:61)
at com.crashlytics.android.core.CrashlyticsCore.onPreExecute(CrashlyticsCore.java:219)
at com.crashlytics.android.core.CrashlyticsCore.onPreExecute(CrashlyticsCore.java:207)
at io.fabric.sdk.android.InitializationTask.onPreExecute(InitializationTask.java:44)
at io.fabric.sdk.android.services.concurrency.AsyncTask.executeOnExecutor(AsyncTask.java:611)
at io.fabric.sdk.android.services.concurrency.PriorityAsyncTask.executeOnExecutor(PriorityAsyncTask.java:43)
at io.fabric.sdk.android.Kit.initialize(Kit.java:69)
at io.fabric.sdk.android.Fabric.initializeKits(Fabric.java:440)
at io.fabric.sdk.android.Fabric.init(Fabric.java:384)
at io.fabric.sdk.android.Fabric.setFabric(Fabric.java:342)
at io.fabric.sdk.android.Fabric.with(Fabric.java:313)
at info.nightscout.android.UploaderApplication.onCreate(UploaderApplication.java:32)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1046)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:5402)
at android.app.ActivityThread.-wrap2(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1541)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6123)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)
09-26 12:38:20.202 6324-6379/info.nightscout.android E/Fabric: Error dealing with settings
java.lang.IllegalArgumentException: Fabric could not be initialized, API key missing from AndroidManifest.xml. Add the following tag to your Application element
<meta-data android:name="io.fabric.ApiKey" android:value="YOUR_API_KEY"/>
at io.fabric.sdk.android.services.common.ApiKey.logErrorOrThrowException(ApiKey.java:110)
at io.fabric.sdk.android.services.common.ApiKey.getValue(ApiKey.java:61)
at io.fabric.sdk.android.services.settings.Settings.initialize(Settings.java:78)
at io.fabric.sdk.android.Onboarding.retrieveSettingsData(Onboarding.java:124)
at io.fabric.sdk.android.Onboarding.doInBackground(Onboarding.java:99)
at io.fabric.sdk.android.Onboarding.doInBackground(Onboarding.java:45)
at io.fabric.sdk.android.InitializationTask.doInBackground(InitializationTask.java:63)
at io.fabric.sdk.android.InitializationTask.doInBackground(InitializationTask.java:28)
at io.fabric.sdk.android.services.concurrency.AsyncTask$2.call(AsyncTask.java:311)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:428)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1133)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:607)
at java.lang.Thread.run(Thread.java:761)
09-26 12:38:20.252 6324-6324/info.nightscout.android W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
09-26 12:38:20.349 6324-6324/info.nightscout.android I/MainActivity: onCreate called
09-26 12:38:20.652 6324-6324/info.nightscout.android D/AndroidRuntime: Shutting down VM
09-26 12:38:20.652 6324-6324/info.nightscout.android E/AndroidRuntime: FATAL EXCEPTION: main
Process: info.nightscout.android, PID: 6324
java.lang.RuntimeException: Unable to start activity ComponentInfo{info.nightscout.android/info.nightscout.android.medtronic.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2659)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2724)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1473)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6123)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
at info.nightscout.android.medtronic.MainActivity.onCreate(MainActivity.java:349)
at android.app.Activity.performCreate(Activity.java:6672)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1140)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2612)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2724) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1473) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6123) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:757) 

Move the code setContentView(R.layout.activity_main);
under the super.onCreate(savedInstanceState);

you are mapping the views before adding layout in your code.
your onCreate() should be
#Override
public void onCreate(Bundle savedInstanceState) {
Log.i(TAG, "onCreate called");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Do mapping all views

Your Error log is showing you your solution. The project is using Fabric API. So naturally you need to add Fabric API key to your project.
Do as suggested in Error log. Add following line in Android Manifest.
<meta-data android:name="io.fabric.ApiKey" android:value="YOUR_API_KEY"/>
For your API key, make a project using Fabric account and get your API key.

Android removeView crashed

I'm creating a screen lock app, and faced notification able to drag down in the lock screen.
I've research it and found this solution to block the notification bar by using addView code below, but I cannot remove the view after user unlocked my app. Please advice how to remove the view.
I've try to use manager.removeView(view); in public void onDestroy() { but it crashed after run this code.
This is the error message
FATAL EXCEPTION: main
Process: com.mehuljoisar.lockscreen, PID: 10256
java.lang.IllegalArgumentException: View=android.view.View{42348cc0 V.ED.... ........ 0,0-0,0} not attached to window manager
at android.view.WindowManagerGlobal.findViewLocked(WindowManagerGlobal.java:373)
at android.view.WindowManagerGlobal.removeView(WindowManagerGlobal.java:302)
at android.view.WindowManagerImpl.removeView(WindowManagerImpl.java:79)
at com.mehuljoisar.lockscreen.LockScreenActivity.disablePullNotificationTouch(LockScreenActivity.java:261)
at com.mehuljoisar.lockscreen.LockScreenActivity.access$100(LockScreenActivity.java:24)
at com.mehuljoisar.lockscreen.LockScreenActivity$2.onClick(LockScreenActivity.java:113)
at android.view.View.performClick(View.java:4469)
at android.view.View$PerformClick.run(View.java:18788)
at android.os.Handler.handleCallback(Handler.java:808)
at android.os.Handler.dispatchMessage(Handler.java:103)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5347)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:835)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:651)
at dalvik.system.NativeStart.main(Native Method)
Where should I put the removeView code?
private void disablePullNotificationTouch(String gg) {
WindowManager manager = ((WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE));
WindowManager.LayoutParams localLayoutParams = new WindowManager.LayoutParams();
localLayoutParams.type = WindowManager.LayoutParams.TYPE_SYSTEM_ERROR;
localLayoutParams.gravity = Gravity.TOP; //make the line top
localLayoutParams.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE |
// this is to enable the notification to recieve touch events
WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL |
// Draws over status bar
WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN;
localLayoutParams.width = WindowManager.LayoutParams.MATCH_PARENT;
localLayoutParams.height = (int) (25 * getResources().getDisplayMetrics().scaledDensity);
localLayoutParams.format = PixelFormat.RGBX_8888;
View view = new View(this);
if(gg == "on") {
manager.addView(view, localLayoutParams);
}else {
manager.removeView(view);
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
disablePullNotificationTouch("on");
}
#Override
public void onDestroy() {
super.onDestroy();
disablePullNotificationTouch("off");
}

You use
WindowManager manager = ((WindowManager) this.getSystemService(Context.WINDOW_SERVICE));
Not use
WindowManager manager = ((WindowManager) getApplicationContext().getSystemService(Context.WINDOW_SERVICE));
Try it!

Android: Unable to create MediaPlayer

I'm trying to run a simple test app to stream music from an online shoutcast radio but I'm always getting an error about MediaPlayer setDataSource() method.. This is the log:
08-26 11:33:42.268 17698-17698/com.example.bruno.radioteste D/MainActivity﹕ Attempt to play http://50.7.98.106:8398
08-26 11:33:42.268 17698-17698/com.example.bruno.radioteste E/MediaPlayer﹕ Unable to create media player
08-26 11:33:42.268 17698-17698/com.example.bruno.radioteste W/System.err﹕ java.io.IOException: setDataSource failed.: status=0x80000000
08-26 11:33:42.278 17698-17698/com.example.bruno.radioteste W/System.err﹕ at android.media.MediaPlayer._setDataSource(Native Method)
The code is very simple, and from what I've been searching it should work just fine.. The layout's xml:
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="BassDrive-http://50.7.98.106:8398"
android:onClick="play" />
And the activity class:
public class MainActivity extends AppCompatActivity implements MediaPlayer.OnPreparedListener {
private static final String TAG = MainActivity.class.getSimpleName();
private MediaPlayer player;
private boolean isPlaying = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
player = new MediaPlayer();
player.setOnPreparedListener(this);
player.setAudioStreamType(AudioManager.STREAM_MUSIC);
}
public void play(View view) {
if(isPlaying) {
player.stop();
isPlaying = false;
} else {
try {
String stationIp = ((Button)view).getText().toString().split("-")[1];
Log.d(TAG, "Attempt to play " + stationIp);
player.setDataSource(stationIp);
player.prepareAsync();
isPlaying = true;
} catch(Exception e) {
e.printStackTrace();
}
}
}
#Override
public void onPrepared(MediaPlayer mp) {
Log.d(TAG, "Trying to start...");
mp.start();
}
#Override
protected void onStop() {
super.onStop();
// clear media player
player.stop();
player.release();
player = null;
}

There are two possible cases,
Have you added this permission in your manifest?
<uses-permission android:name="android.permission.INTERNET" />
If yes, then android is not able to decode your stream. To test this you can try some other stream. For example, try a spotify 30-second preview stream http://d318706lgtcm8e.cloudfront.net/mp3-preview/d9d8686acc79916d2db76abdaa2c18a594fed332

Can't play this video. Android videoView mp4 recorded by android device

I've looked for existing potential solutions with other formats and those still responds with mentioned error.
Finally, recorded the video with the same device and used it as a resource for this app and it still doesn't work.
Devices: SGS2, lenovo a820
Video type: MPEG-4 video (video/mp4)
videoView = (VideoView)findViewById(R.id.videoView);
videoView.setVideoPath("android.resource://raw/sample.mp4");
videoView.start();

Please refer below code snippet...problem was with the path declaration..
String uriPath = "android.resource://"+getPackageName()+"/"+R.raw.aha_hands_only_cpr_english;
Uri uri = Uri.parse(uriPath);
mVideoView.setVideoURI(uri);
Thats it...

I tried everything mentioned before but it turns out that internet permission is needed to play a mp4 file.
<uses-permission android:name="android.permission.INTERNET" />

try following code..
videoView = (VideoView)this.findViewById(R.id.videoView);
String path = "android.resource://" + getPackageName() + "/" + R.raw.video_file;
MediaController mc = new MediaController(this);
videoView.setMediaController(mc);
videoView.start();

public class videoplayer extends Activity {
private static final String Videos_URL = "*your URI*";
private VideoView myVideoView;
private int position = 0;
private ProgressDialog progressDialog;
private MediaController mediaControls;
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Get the layout from video_main.xml
setContentView(R.layout.activity_main);
if (mediaControls == null) {
mediaControls = new MediaController(this);
}
// Find your VideoView in your video_main.xml layout
myVideoView = (VideoView) findViewById(R.id.videoView);
// Create a progressbar
progressDialog = new ProgressDialog(this);
// Set progressbar title
progressDialog.setTitle("ABCDEFGH");
// Set progressbar message
progressDialog.setMessage("Loading...");
progressDialog.setCancelable(false);
// Show progressbar
progressDialog.show();
try {
Uri video = Uri.parse(Videos_URL);
myVideoView.setVideoURI(video);
myVideoView.setMediaController(mediaControls);
} catch (Exception e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
myVideoView.requestFocus();
myVideoView.setOnPreparedListener(new OnPreparedListener() {
// Close the progress bar and play the video
public void onPrepared(MediaPlayer mp) {
progressDialog.dismiss();
myVideoView.seekTo(position);
if (position == 0) {
myVideoView.start();
} else {
myVideoView.pause();
}
}
});
}
#Override
public void onSaveInstanceState(Bundle savedInstanceState) {
super.onSaveInstanceState(savedInstanceState);
savedInstanceState.putInt("Position", myVideoView.getCurrentPosition());
myVideoView.pause();
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
position = savedInstanceState.getInt("Position");
myVideoView.seekTo(position);
}
}

Be sure that the decoder (target sdk) supports the video format you are using. You can use VLC Player to convert video format to the desired one. In my case, I converted the MP4 to WebM file and load it in the VideoView.
Here is how you get the file path and play your video.
String path = "android.resource://" + getPackageName() + "/" + R.raw.sample;
VideoView videoView = (VideoView)findViewById(R.id.videoView);
videoView.setVideoURI(Uri.parse(path));
videoView.start()
Source:
Video format and codec support
https://developer.android.com/guide/topics/media/media-formats.html

For Lenovo a820 ,below is need :
- MP4/WMV/H.264/H.263 player
- MP3/WAV/WMA/eAAC+ player
make sure that ur video fits in above codec format.

Just Replace your code with this code and it will be working:
VideoView videoView = findViewById(R.id.videoView);
videoView.setVideoPath("android.resource://" + getPackageName() + "/" + R.raw.sample);
videoView.start();

I think the issue is with the device on which we try to play video, sometimes it doesn't support.
I tried running it on Linux emulatoe

Try this following code it works..........
VideoView videoView=(VideoView)findViewById(R.id.videoView);
videoView.setVideoPath("android.resource://"+getPackageName()+"/"+R.raw.videoname;
videoView.start();