Android java : How to copy/move file from assets to absolute path?

    private void moveAssets(String assets_file_path, String absolutePath) throws IOException {
        File wwwFile = new File(absolutePath);
        if (wwwFile.exists())
            return;
        InputStream is = activity.getAssets().open(assets_file_path);
        byte[] buffer = new byte[is.available()];
        is.read(buffer);
        is.close();
        wwwFile.createNewFile();
        FileOutputStream os = new FileOutputStream(wwwFile);
        os.write(buffer);
        os.close();
    }

TOP 16515 words from Corpus of Contemporary American English

Download for Android
https://play.google.com/store/apps/details?id=com.lengerrong.coca

Android java: How to orientation activity layout automatically ?

Add ~android:screenOrientation="fullSensor"~ to the activity

 AndroidManifest.xml activity android:name=".MainActivity"             android:screenOrientation="fullSensor" 

shell bash scripts : check process existed or not, if not existed then restart it

Put below scripts in your ~/.bash_profile or ~/.bashrc
It will auto run "unison" process if not running yet
when you open a new bash shell every time.
Change the process name "unison" for your case. :)

auto_unison() {
    u=`ps aux | grep unison | grep -v grep | wc -l`
    if [ $u -eq 0 ]
    then
        unison > /dev/null 2>&1 &
    fi
}
auto_unison

Android how to detect/register language/locale change listener/receiver

The easy way is to register a BroadcastReceiver for Intent.ACTION_LOCALE_CHANGED.

Example: change your ViewModel data when language/locale changed.

public class QASViewModel extends ViewModel {
    @SuppressLint("StaticFieldLeak")
    private final FragmentActivity activity;

    public QASViewModel(@NonNull FragmentActivity activity) {
        this.activity = activity;
        setLangReceiver();
    }

    private void setLangReceiver() {
        final QASViewModel qasViewModel = this;
        final BroadcastReceiver langReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                // do action when language change
            }
        };
        activity.getApplicationContext().registerReceiver(langReceiver,
                new IntentFilter(Intent.ACTION_LOCALE_CHANGED));
    }
}

Android ViewModel with ArgsConstructor via Custom ViewModelFactory

Android ViewModel is very useful.
However ViewModel has no args constructor by default.

Typical usage of ViewModel looks like:

public class UserModel extends ViewModel {
} 
final UserModel viewModel = ViewModelProviders.of(this).get(UserModel.class);

Let's look the definition of ViewModelProviders.of method.

    /**
     * Creates a {@link ViewModelProvider}, which retains ViewModels while a scope of given Activity
     * is alive. More detailed explanation is in {@link ViewModel}.
     * 

     * It uses the given {@link Factory} to instantiate new ViewModels.
     *
     * @param activity an activity, in whose scope ViewModels should be retained
     * @param factory  a {@code Factory} to instantiate new ViewModels
     * @return a ViewModelProvider instance
     */
    @NonNull
    @MainThread
    public static ViewModelProvider of(@NonNull FragmentActivity activity,
            @Nullable Factory factory) {

Have you found it? We can pass a Factory to create the ViewModel.
Implement your own Factory then you can have args constructor for your ViewModel.

Here we set up a ViewModel with 1 argument construcgtor.
Example code:

    public QASViewModel(@NonNull FragmentActivity activity) {
        this.activity = activity;
    }
    
QASViewModel qasViewModel = ViewModelProviders.of(getActivity(),
                new QASViewModelFactory(getActivity())).get(QASViewModel.class);

import androidx.annotation.NonNull;
import androidx.fragment.app.FragmentActivity;
import androidx.lifecycle.ViewModel;
import androidx.lifecycle.ViewModelProvider;

import java.lang.reflect.InvocationTargetException;

public class QASViewModelFactory extends ViewModelProvider.NewInstanceFactory {

    private final FragmentActivity activity;

    /**
     * Creates a {@code AndroidViewModelFactory}
     *
     * @param activity an AssetManager to pass in {@link QASViewModel}
     */
    public QASViewModelFactory(@NonNull FragmentActivity activity) {
        this.activity = activity;
    }

    @NonNull
    @Override
    public  T create(@NonNull Class modelClass) {
        if (QASViewModel.class.isAssignableFrom(modelClass)) {
            try {
                return modelClass.getConstructor(FragmentActivity.class).newInstance(activity);
            } catch (NoSuchMethodException e) {
                throw new RuntimeException("Cannot create an instance of " + modelClass, e);
            } catch (IllegalAccessException e) {
                throw new RuntimeException("Cannot create an instance of " + modelClass, e);
            } catch (InstantiationException e) {
                throw new RuntimeException("Cannot create an instance of " + modelClass, e);
            } catch (InvocationTargetException e) {
                throw new RuntimeException("Cannot create an instance of " + modelClass, e);
            }
        }
        return super.create(modelClass);
    }
}

How to convert UTC Date Time String to Java object and compare it ?

Use java.time.Instant;

import java.time.Instant;

Instant instantStart = Instant.parse("20200229T12:00:00Z");
Instant instantEnd = Instant.parse("20200329T12:00:00Z");
Instant instantNow = Instant.now();

return instantNow.isAfter(instantStart) &&  
       instantNow.isBefore(instantEnd);