Google Associate Android Developer Practice Test - Questions Answers, Page 8

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?

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:

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:

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:

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

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:

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 @Override

public <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"?

What is demonstrated by the code below?

// RawDao.java @Dao

interface RawDao {

@RawQuery

User 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); ...

What happens when you create a DAO method and annotate it with @Insert?

Example:

@Dao

public interface MyDao {

@Insert(onConflict = OnConflictStrategy.REPLACE) public void insertUsers(User... users); }