About running a debuggable build variant. Usually, you can just select the default "debug" variant that's included in every Android Studio project (even though it's not visible in the build.gradle file). But if you define new build types that should be debuggable, you must add 'debuggable true' to the build type. Is that mostly true?

No, if you define new build types that should be debuggable, you must add 'debuggable false'

No, the debug variant should be visible in the build.gradle file anyway.

As an example. Our MutableLiveData<Long> object, named mLapseTime, is not connected to a Room database, etc. How can we change the value in mLapseTime?

mLapseTime.postValue("new String")

Interface for a callback to be invoked when a shared preference is changed. Interface is named:

android.content.SharedPreferences.OnSharedPreferenceChangeListener

android.content.SyncStatusObserver

android.content.SharedPreferences.Editor

android.content.SharedPreferences.OnSharedPreferenceChangeListener

android.content.SharedPreferences

With our Context we can get SharedPreferences with a method, named: getSharedPreferences(String name, int mode). What value can we transfer in a "mode"parameter?

Value is either 0 or a combination of MODE_PRIVATE, MODE_WORLD_READABLE,

combination of MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE

Value is either 0 or a combination of MODE_PRIVATE, MODE_WORLD_READABLE,

MODE_WORLD_WRITEABLE, and MODE_MULTI_PROCESS

What statements about InputStreamReader (java.io.InputStreamReader) are correct? (Choose two.)

An InputStreamReader is a bridge from byte streams to character streams: It reads bytes and decodes them into characters using a specified charset. The charset that it uses may be specified by name or may be given explicitly, or the platform's default charset may be accepted.

Each invocation of one of an InputStreamReader's read() methods may cause one or more bytes to be read from the underlying byte-input stream. To enable the efficient conversion of bytes to characters, more bytes may be read ahead from the underlying stream than are necessary to satisfy the current read operation.

An InputStreamReader is a bridge from byte streams to character streams: It reads bytes and decodes them into characters using a specified charset. The charset that it uses may be specified by name or may be given explicitly, or the platform's default charset may be accepted.

An InputStreamReader is a bridge from character streams to byte streams: It reads characters using a specified charset and encodes them into bytes. The charset that it uses may be specified by name or may be given explicitly, or the platform's default charset may be accepted.

Each invocation of one of an InputStreamReader's read() methods may cause one or more bytes to be read from the underlying byte-input stream. To enable the efficient conversion of bytes to characters, more bytes may be read ahead from the underlying stream than are necessary to satisfy the current read operation.

No any invocation of one of an InputStreamReader's read() methods can cause some bytes to be read from the underlying byte-input stream.

What is the incorrect statement about Data Access Object (androidx.room.Dao)?

It is recommended to have only one Dao class in your codebase for all tables.

Data Access Objects are the main classes where you define your database interactions. They can include a variety of query methods.

The class marked with @Dao should either be an interface or an abstract class. At compile time, Room will generate an implementation of this class when it is referenced by a Database.

An abstract @Dao class can optionally have a constructor that takes a Database as its only parameter.

It is recommended to have only one Dao class in your codebase for all tables.

By adding a RoomDatabase.Callback to the room database builder RoomDatabase.Builder (method addCallback(RoomDatabase.Callback callback)), we can: (Choose two.)

handle database first time creation

disable the main thread query check for Room

By executing an allowMainThreadQueries() method to the room database builder RoomDatabase.Builder, we can:

disable the main thread query check for Room

handle database first time creation

disable the main thread query check for Room

If you added to your build.gradle file a room.schemaLocation:android { defaultConfig { javaCompileOptions { annotationProcessorOptions {arguments = ["room.schemaLocation": "$projectDir/schemas".toString()]}}}}Then, you build your app or module.As a result you got a json file, with such path to it:app/schemas/your_app_package/db_package/DbClass/DB_VERSION.jsonWhat are the correct statements about this file? (Choose all that apply.)

It's a file with Room-exported schema

Main JSONObject in this file usually should contain a number "formatVersion" and a JSONObject "database"

The JSONObject "database" in this file usually should contain such objects, like "entities", "views", "setupQueries", ets.

It's a file with Room-exported schema

Main JSONObject in this file usually should contain a number "formatVersion" and a JSONObject "database"

The JSONObject "database" in this file usually should contain such objects, like "entities", "views", "setupQueries", ets.

@Query is the main annotation used in DAO classes. It allows you to perform read/write operations on a database. Each @Query method is verified at compile time, so what happens if there is a problem with the query?

a compilation error occurs instead of a runtime failure.

a runtime error occurs instead of a compilation failure.

a compilation error occurs instead of a runtime failure.

both compilation error and runtime failure occurs.

About queries in DAO classes. Room verifies the return value of the query such that if the name of the field in the returned object doesn't match the corresponding column names in the query response, Room alerts you in one of the following two ways: (Choose two.)

It gives a warning if only some field names match.

It gives an error if no field names match.

It gives a warning if no field names match.

It gives a warning if only some field names match.

It gives an error if no field names match.

It gives an error if only some field names match.

What is a correct part of an Implicit Intent for sharing data implementation?

Intent sendIntent = new Intent(); sendIntent.setAction(Intent.ACTION_SEND);

Intent sendIntent = new Intent(this, UploadService.class) sendIntent.putExtra(Intent.EXTRA_TEXT, textMessage);

Intent sendIntent = new Intent(); sendIntent.setType(Intent.ACTION_SEND);

Intent sendIntent = new Intent(this, UploadService.class) sendIntent.setData(Uri.parse(fileUrl));

Intent sendIntent = new Intent(); sendIntent.setAction(Intent.ACTION_SEND);

By default, the notification's text content is truncated to fit one line. If you want your notification to be longer, for example, to create a larger text area, you can do it in this way:

NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID).setContentText("Much longer text that cannot fit one line...").setStyle(new NotificationCompat.BigTextStyle().bigText("Much longer text that cannot fit one line..."))

NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID).setContentText("Much longer text that cannot fit one line...").setLongText("Much longer text that cannot fit one line..."))

NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID).setContentText("Much longer text that cannot fit one line...") .setTheme(android.R.style.Theme_LongText); ...

"workManager" is an instance of WorkManager. Select correct demonstration of WorkRequest cancellation:

WorkRequest request = new OneTimeWorkRequest.Builder(FooWorker.class).build(); workManager.enqueue(request);workManager.cancelWorkById(request.getId());

workManager.enqueue(new OneTimeWorkRequest.Builder(FooWorker.class).build());

WorkRequest request = new OneTimeWorkRequest.Builder(FooWorker.class).build(); workManager.enqueue(request);LiveData<WorkInfo> status = workManager.getWorkInfoByIdLiveData(request.getId()); status.observe(...);

WorkRequest request = new OneTimeWorkRequest.Builder(FooWorker.class).build(); workManager.enqueue(request);workManager.cancelWorkById(request.getId());

WorkRequest request1 = new OneTimeWorkRequest.Builder(FooWorker.class).build();WorkRequest request2 = new OneTimeWorkRequest.Builder(BarWorker.class).build(); WorkRequest request3 = new OneTimeWorkRequest.Builder(BazWorker.class).build(); workManager.beginWith(request1, request2).then(request3).enqueue();

WorkRequest request = new OneTimeWorkRequest.Builder(FooWorker.class).build(); workManager.enqueue(request); workManager.cancelWork(request);

In general, you should send an AccessibilityEvent whenever the content of your custom view changes. For example, if you are implementing a custom slider bar that allows a user to select a numeric value by pressing the left or right arrows, your custom view should emit an event of type TYPE_VIEW_TEXT_CHANGED whenever the slider value changes. Which one of the following sample codes demonstrates the use of the sendAccessibilityEvent() method to report this event.

@Override public boolean onKeyUp (int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) { currentValue--;sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED); return true;}

@Override public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { boolean completed = super.dispatchPopulateAccessibilityEvent(event); CharSequence text = getText(); if (!TextUtils.isEmpty(text)) { event.getText().add(text); return true;}return completed;}

@Override public boolean onKeyUp (int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_DPAD_LEFT) { currentValue--;sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_TEXT_CHANGED); return true;}

@Override public boolean onKeyUp (int keyCode, KeyEvent event) { if (keyCode == KeyEvent.KEYCODE_ENTER) { currentValue--;sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CONTEXT_CLICKED); return true;}

The easiest way of adding menu items (to specify the options menu for an activity) is inflating an XML file into the Menu via MenuInflater. With menu_main.xml we can do it in this way:

@Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.menu_main, menu); return true;}

@Override public boolean onOptionsItemSelected(MenuItem item) { getMenuInflater().inflate(R.menu.menu_main, menu); returnsuper.onOptionsItemSelected(item); }

@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.menu.menu_main); }

Android Tests. You can use the childSelector() method to nest multiple UiSelector instances. For example, the following code example shows how your test might specify a search to find the first ListView in the currently displayed UI, then search within that ListView to find a UI element with the text property Apps. What is the correct sample?

UiObject appItem = device.findObject(new UiSelector().className("android.widget.ListView").instance(0).childSelector(new UiSelector().text("Apps")));

UiObject appItem = device.findObject(new UiSelector().className(ListView.class).instance(1).childSelector(new UiSelector().text("Apps")));

UiObject appItem = device.findObject(new UiSelector().className("android.widget.ListView").instance(0).childSelector(new UiSelector().text("Apps")));

UiObject appItem = device.findObject(new UiSelector().className("android.widget.ListView").instance(new UiSelector().text("Apps")));

The following code snippet shows an example of an Espresso test:

@Test public void greeterSaysHello() {onView(withId(R.id.name_field)).perform(typeText("Steve")); onView(withId(R.id.greet_button)).perform(click());onView(withText("Hello Steve!")).check(matches(isDisplayed())); }

@Rule public void greeterSaysHello() {onView(withId(R.id.name_field)).do(typeText("Steve")); onView(withId(R.id.greet_button)).do(click());onView(withText("Hello Steve!")).check(matches(isDisplayed())); }

@Test public void greeterSaysHello() {onView(withId(R.id.name_field)).perform(typeText("Steve")); onView(withId(R.id.greet_button)).perform(click());onView(withText("Hello Steve!")).check(matches(isDisplayed())); }

@Test public void greeterSaysHello() {onView(withId(R.id.name_field)).do(typeText("Steve")); onView(withId(R.id.greet_button)).do(click());onView(withText("Hello Steve!")).compare(matches(isDisplayed())); }

As an example. In an Activity we have our TimerViewModel object (extended ViewModel), named mTimerViewModel. mTimerViewModel.getTimer() method returns a LiveData<Long> value. What can be a correct way to set an observer to change UI in case if data was changed?

mTimerViewModel.getTimer().observe(this, new Observer<Long>() { @Overridepublic void onChanged(Long aLong) { callAnyChangeUIMethodHere(aLong)}});

mTimerViewModel.getTimer().getValue().toString().observe(new Observer<Long>() { @Overridepublic void onChanged(Long aLong) { callAnyChangeUIMethodHere(aLong)}});

mTimerViewModel.getTimer().observe(this, new Observer<Long>() { @Overridepublic void onChanged(Long aLong) { callAnyChangeUIMethodHere(aLong)}});

mTimerViewModel.observe(new Observer<Long>() { @Overridepublic void onChanged(Long aLong) { callAnyChangeUIMethodHere(aLong)}});

LiveData.postValue() and LiveData.setValue() methods have some differences. So if you have a following code executed in the main thread:liveData.postValue("a"); liveData.setValue("b");What will be the correct statement?

The value "a" would be set at first and later the main thread would override it with the value "b".

The value "b" would be set at first and later the main thread would override it with the value "a".

The value "a" would be set at first and later the main thread would override it with the value "b".

The value "b" would be set at first and would not be overridden with the value "a".

The value "a" would be set at first and would not be overridden with the value "b".

In our TeaViewModel class, that extends ViewModel, we have such method:public LiveData<Tea> getTea() { return mTea; }An observer in our Activity (type of mViewModel variable in example is TeaViewModel) is set in this way:mViewModel.getTea().observe(this, this::displayTea);What will be a correct displayTea method definition?

private void displayTea(Tea tea)

private void displayTea(LiveData<Tea>)

private void displayTea(LiveData<T>)

For example, our preferences.xml file was added by addPreferencesFromResource(R.xml.preferences). Our preferences.xml file contains such item:<SwitchPreference android:id="@+id/notification" android:key="@string/pref_notification_key" android:title="@string/pref_notification_title"android:summary="@string/pref_notification_summary" android:defaultValue="@bool/pref_notification_default_value" app:iconSpaceReserved="false"/>In our Fragment, we can dynamically get current notification preference value in this way:

boolean isNotificationOn = PreferenceManager.getDefaultSharedPreferences(getContext()).getBoolean( getContext().getString(R.string.pref_notification_key),getContext().getResources().getBoolean(R.bool.pref_notification_default_value) );

boolean isNotificationOn = PreferenceManager.getSharedPreferences(getContext()).getBoolean( getContext().getString(R.string.pref_notification_default_value), getContext().getString(R.string.pref_notification_key) );

boolean isNotificationOn = PreferenceManager.getSharedPreferences(getContext()).getBoolean( getContext().getResources().getBoolean(R.bool.pref_notification_default_value), getContext().getString(R.string.pref_notification_key) );

For example, our preferences.xml file was added by addPreferencesFromResource(R.xml.preferences). Our preferences.xml file contains such item:<ListPreference android:id="@+id/order_by" android:key="@string/pref_sort_key" android:title="@string/pref_sort_title" android:summary="@string/pref_sort_summary" android:dialogTitle="@string/pref_sort_dialog_title" android:entries="@array/sort_oder" android:entryValues="@array/sort_oder_value"android:defaultValue="@string/pref_default_sort_value" app:iconSpaceReserved="false" />In our Fragment, we can dynamically get current notification preference value in this way:

String sortBy = PreferenceManager.getDefaultSharedPreferences(getContext()).getString( getContext().getString(R.string.pref_sort_key), getContext().getString(R.string.pref_default_sort_value) )

String sortBy = PreferenceManager.getDefaultSharedPreferences(getContext()).getString( getContext().getString(R.string.pref_sort_key),getContext().getResources().getBoolean(R.bool.pref_default_sort_value) );

String sortBy = PreferenceManager.getSharedPreferences(getContext()).getString( getContext().getString(R.string.pref_default_sort_value),getContext().getString(R.string.pref_sort_key) );

boolean sortBy = PreferenceManager.getSharedPreferences(getContext()).getBoolean( getContext().getResources().getBoolean(R.bool.pref_default_sort_value), getContext().getString(R.string.pref_sort_key) );

String sortBy = PreferenceManager.getDefaultSharedPreferences(getContext()).getString( getContext().getString(R.string.pref_sort_key), getContext().getString(R.string.pref_default_sort_value) )

For example, we have a file in our raw folder app/src/main/res/raw/sample_teas.json. To get an InputStream for reading it, from out Context context, we can do this:

InputStream input = context.getResources().openRawResource(R.raw.sample_teas);

InputStream input = context.openRawResource(R.raw.sample_teas);

InputStream input = context.getRawResource(R.raw.sample_teas);

InputStream input = context.getResources().openRawResource(R.raw.sample_teas);

For example, we have a BufferedReader reader, associated with the json file through InputStreamReader. To get a file data we can do this:

String line; try {while ((line = reader.readLine()) != null) { builder.append(line);}JSONObject json = new JSONObject(builder.toString()); return json;} catch (IOException | JSONException exception) { exception.printStackTrace();}

JSONObject line; try {while ((line = reader.readJSONObject ()) != null) { builder.append(line);}JSONObject json = new JSONObject(builder.toString()); return json;} catch (IOException | JSONException exception) { exception.printStackTrace();}

String line; try {while ((line = reader.readLine()) != null) { builder.append(line);}JSONObject json = new JSONObject(builder.toString()); return json;} catch (RuntimeException|ArrayIndexOutOfBoundsException exception) { exception.printStackTrace();}

For example, we have a file in our assets folder app/src/main/assets/sample_teas.json. To get an InputStream for reading it, from out Context context, we can try doing this:

InputStream input = context.getAssets().open("sample_teas.json");

InputStream input = context.getResources().openRawResource(R.raw.sample_teas);

InputStream input = context.getAssets().open("sample_teas.json");

InputStream input = context.getResources().getAssets().open("sample_teas.json");

An example. In our ViewModelFactory (that implements ViewModelProvider.Factory) we have an instance of our Repository, named mRepository. Our ViewModel has such constructor:public MyViewModel(MyRepository myRepository)...Next, in our ViewModelFactory create ViewModel method (overriden) looks like this: @NonNull @Overridepublic <T extends ViewModel> T create(@NonNull Class<T> modelClass) { try {//MISSED RETURN VALUE HERE} catch (InstantiationException | IllegalAccessException | NoSuchMethodException | InvocationTargetException e) {throw new RuntimeException("Cannot create an instance of " + modelClass, e);}}What should we write instead of "//MISSED RETURN VALUE HERE"?

return modelClass.getConstructor(MyRepository.class).newInstance(mRepository);

return modelClass.getConstructor().newInstance(mRepository);

return modelClass.getConstructor(MyRepository.class).newInstance();

return modelClass.getConstructor(MyRepository.class).newInstance(mRepository);

What is demonstrated by the code below?// RawDao.java @Daointerface RawDao {@RawQueryUser getUserViaQuery(SupportSQLiteQuery query); }// Usage of RawDao ...SimpleSQLiteQuery query =new SimpleSQLiteQuery("SELECT * FROM User WHERE id = ? LIMIT 1", new Object[]{userId});User user = rawDao.getUserViaQuery(query); ...

A method in a Dao annotated class as a raw query method where you can pass the query as a SupportSQLiteQuery.

A method in a Dao annotated class as a query method.

A method in a RoomDatabase class as a query method.

What happens when you create a DAO method and annotate it with @Insert?Example:@Daopublic interface MyDao {@Insert(onConflict = OnConflictStrategy.REPLACE) public void insertUsers(User... users); }

Room generates an implementation that inserts all parameters into the database in a single transaction.

Room modifies a set of entities, given as parameters, in the database. It uses a query that matches against the primary key of each entity.

Room removes a set of entities, given as parameters, from the database. It uses the primary keys to find the entities to delete.

Google Associate Android Developer Practice Test 2 - Free Online Exam Prep & Questions

To run a debuggable build variant you must use a build variant that includes

minifyEnabled false in the build configuration

debuggable true or debuggable false in the build configuration

debuggable true in the build configuration

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