RushOrm

Способ 1:
Через library сгенерировать har-пакет, добавить har-пакет в папку libs.
В entry gradle добавить следующий код:
implementation fileTree(dir: 'libs', include: ['*.jar', '*.har'])

Способ 2:
allprojects{
    repositories{
        mavenCentral()
    }
}
implementation 'io.openharmony.tpc.thirdlib:RushOrm_rushohos:1.0.6'

1.
public class Car extends RushObject {

    public String color;
    public Engine engine;

    public String anotherField;

    @RushList(classType = Wheel.class)
    public List<Wheel> wheels;

    public Car(){
        /* Empty constructor required */
    }

    public Car(String color, Engine engine){
        this.color = color;
        this.engine = engine;
    }
}


public class MainAbility extends Ability {
    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);
        super.setMainRoute(MainAbilitySlice.class.getName());
        List<Class<? extends Rush>> classes = new ArrayList<>();
        classes.add(Car.class);
        classes.add(Engine.class);
        classes.add(Wheel.class);
        OhosInitializeConfig ohosInitializeConfig = new OhosInitializeConfig(getApplicationContext(), classes);
        RushOhos.initialize(ohosInitializeConfig);
    }
}

2.
Button btnSave = (Button) findComponentById(ResourceTable.Id_btn_save);
Button btnSelect = (Button) findComponentById(ResourceTable.Id_btn_select);
Button btnDel = (Button) findComponentById(ResourceTable.Id_btn_del);
Text tvShow = (Text) findComponentById(ResourceTable.Id_text_show);
//сохранение
btnSave.setClickedListener(component -> {
    final long startTime = System.currentTimeMillis();
    final int numberToSave = 100;
    List<Car> cars = new ArrayList<>(numberToSave);
    for (int i = 0; i < numberToSave; i++) {
        Car car = new Car("Red", new Engine());
        car.wheels = new ArrayList<>();
        for (int j = 0; j < 4; j++) {
            car.wheels.add(new Wheel("Michelin"));
        }
        cars.add(car);
    }

    RushCore.getInstance().save(cars, () -> {
        long endTime = System.currentTimeMillis();
        final double saveTime = (endTime - startTime) / 1000.0;
        getAbility().getContext().getUITaskDispatcher().asyncDispatch(new Runnable() {
            @Override
            public void run() {
                tvShow.setText("Сохранение успешно! Общее затраченное время:"+String.format("%1$,.2f s", saveTime));
            }
``` ```
});
            });
        });
        //查询
        btnSelect.setClickedListener(component -> {
            new Thread(() -> {
                List<Car> cars = new RushSearch().find(Car.class);
                getAbility().getContext().getUITaskDispatcher().asyncDispatch(new Runnable() {
                    @Override
                    public void run() {
                        LogUtil.error("test", "Rush main select complete====");
                        tvShow.setText("查询成功:" + JSON.toJSONString(cars));
                    }
                });
            }).start();
        });
        //删除
        btnDel.setClickedListener(component -> new Thread(() -> {
            RushCore.getInstance().deleteAll(Car.class);
            RushCore.getInstance().deleteAll(Engine.class);
            RushCore.getInstance().deleteAll(Wheel.class);
            getAbility().getContext().getUITaskDispatcher().asyncDispatch(new Runnable() {
                @Override
                public void run() {
                    tvShow.setText("删除成功");
                }
            });
        }).start());