建造者是抽象的；无法实例化。为什么？

Question

我正在尝试实现 Mapbox 的示例之一。他们有一个选项构建器，其实现方式如下所示。但是当我尝试构建它时出现错误

error: Builder is abstract; cannot be instantiated

MapboxNavigationOptions options = new MapboxNavigationOptions.Builder().navigationNotification(customNotification).build();

我不明白这是为什么？这个class不应该是这样用的吗？

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        routeRefresh = new RouteRefresh(Mapbox.getAccessToken(), (RefreshCallback) getApplicationContext());

        mapView.onCreate(savedInstanceState);
        mapView.getMapAsync(this);

        Context context = getApplicationContext();
        CustomNavigationNotification customNotification = new CustomNavigationNotification(context);
        MapboxNavigationOptions options = new MapboxNavigationOptions.Builder().navigationNotification(customNotification).build();

        navigation = new MapboxNavigation(
                this,
                Mapbox.getAccessToken(),
                options
        );

        navigation.addMilestone(new RouteMilestone.Builder()
                .setIdentifier(BEGIN_ROUTE_MILESTONE)
                .setInstruction(new BeginRouteInstruction())
                .setTrigger(
                        Trigger.all(
                                Trigger.lt(TriggerProperty.STEP_INDEX, 3),
                                Trigger.gt(TriggerProperty.STEP_DISTANCE_TOTAL_METERS, 200),
                                Trigger.gte(TriggerProperty.STEP_DISTANCE_TRAVELED_METERS, 75)
                        )
                ).build());
        customNotification.register(new MyBroadcastReceiver(navigation), context);
    }

Answer 1

我通过删除 new 关键字并使用 MapboxNavigationOptions.builder() 而不是 new MapboxNavigationOptions.Builder() 来修复此问题。

建造者是抽象的；无法实例化。为什么？

Builder is abstract; cannot be instantiated. Why?

java

android

abstract-class

mapbox

mapbox-android