从onSuccess获取纬度和经度(LocationEngineResult结果)

Question

我使用覆盖方法获取用户当前位置

public void onSuccess(LocationEngineResult result) {
location = Point.fromLngLat(result.getLastLocation().getLongitude(),result.getLastLocation().getLatitude());
}

但我不知道如何替换可变上的纬度和经度

private final Point ROUTE_ORIGIN=Point.fromLngLat(location.longitude(),location.latitude());

对于我从公共空间onSuccess(LocationEngineResult result)获得的位置，有什么解决方案吗？

应用程序崩溃，出现错误

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'double com.mapbox.geojson.Point.longitude()' on a null object reference

有人能给我一些想法或解决方案吗？我试图找到来源，但仍然无法解决。

public class ArActivity extends BaseActivity implements RouteListener, ProgressChangeListener, OffRouteListener {
private static final String TAG = ArActivity.class.getSimpleName();
// Handles navigation.
private MapboxNavigation mapboxNavigation;
// Fetches route from points.
private RouteFetcher routeFetcher;
private RouteProgress lastRouteProgress;
private PermissionsManager permissionsManager;
private LocationEngine locationEngine;
private LocationEngineCallback<LocationEngineResult> locationCallback;
public Point location;
private boolean visionManagerWasInit = false;
private boolean navigationWasStarted = false;
TextView tvlocation;
// This dummy points will be used to build route. For real world test this needs to be changed to real values for
// source and target location
private final Point ROUTE_ORIGIN=Point.fromLngLat(location.longitude(),location.latitude());
private final Point ROUTE_DESTINATION = Point.fromLngLat(101.769116, 2.923220);
@Override
protected void initViews() {
setContentView(R.layout.activity_ar_navigation);
tvlocation = findViewById(R.id.location);
}
@Override
protected void onPermissionsGranted() {
startVisionManager();
startNavigation();
}
@Override
protected void onStart() {
super.onStart();
startVisionManager();
startNavigation();
}
@Override
protected void onStop() {
super.onStop();
stopVisionManager();
stopNavigation();
}
private void startVisionManager() {
if (allPermissionsGranted() && !visionManagerWasInit) {
// Create and start VisionManager.
VisionManager.create();
VisionManager.setModelPerformanceConfig(new Merged(new On(ModelPerformanceMode.DYNAMIC, ModelPerformanceRate.LOW)));
VisionManager.start();
VisionManager.setVisionEventsListener(new VisionEventsListener() {
@Override
public void onAuthorizationStatusUpdated(@NotNull AuthorizationStatus authorizationStatus) {
}
@Override
public void onFrameSegmentationUpdated(@NotNull FrameSegmentation frameSegmentation) {
}
@Override
public void onFrameDetectionsUpdated(@NotNull FrameDetections frameDetections) {
}
@Override
public void onFrameSignClassificationsUpdated(@NotNull FrameSignClassifications frameSignClassifications) {
}
@Override
public void onRoadDescriptionUpdated(@NotNull RoadDescription roadDescription) {
}
@Override
public void onWorldDescriptionUpdated(@NotNull WorldDescription worldDescription) {
}
@Override
public void onVehicleStateUpdated(@NotNull VehicleState vehicleState) {
}
@Override
public void onCameraUpdated(@NotNull Camera camera) {
}
@Override
public void onCountryUpdated(@NotNull Country country) {
}
@Override
public void onUpdateCompleted() {
}
});
VisionArView visionArView = findViewById(R.id.mapbox_ar_view);
// Create VisionArManager.
VisionArManager.create(VisionManager.INSTANCE);
visionArView.setArManager(VisionArManager.INSTANCE);
visionArView.setFenceVisible(true);
visionManagerWasInit = true;
}
}
private void stopVisionManager() {
if (visionManagerWasInit) {
VisionArManager.destroy();
VisionManager.stop();
VisionManager.destroy();
visionManagerWasInit = false;
}
}
private void startNavigation() {
if (allPermissionsGranted() && !navigationWasStarted) {
// Initialize navigation with your Mapbox access token.
mapboxNavigation = new MapboxNavigation(
this,
getString(R.string.mapbox_access_token),
MapboxNavigationOptions.builder().build()
);
// Initialize route fetcher with your Mapbox access token.
routeFetcher = new RouteFetcher(this, getString(R.string.mapbox_access_token));
routeFetcher.addRouteListener(this);
locationEngine = LocationEngineProvider.getBestLocationEngine(this);
LocationEngineRequest arLocationEngineRequest = new LocationEngineRequest.Builder(0)
.setPriority(LocationEngineRequest.PRIORITY_HIGH_ACCURACY)
.setFastestInterval(1000)
.build();

locationCallback = new LocationEngineCallback<LocationEngineResult> () {
@Override
public void onSuccess(LocationEngineResult result) {
location = Point.fromLngLat(result.getLastLocation().getLongitude(),result.getLastLocation().getLatitude());
}
@Override
public void onFailure(@NonNull Exception exception) {
}
};
try {
locationEngine.requestLocationUpdates(arLocationEngineRequest, locationCallback, Looper.getMainLooper());
} catch (SecurityException se) {
VisionLogger.Companion.e(TAG, se.toString());
}
initDirectionsRoute();
// Route need to be reestablished if off route happens.
mapboxNavigation.addOffRouteListener(this);
mapboxNavigation.addProgressChangeListener(this);
navigationWasStarted = true;
}
}
private void stopNavigation() {
if (navigationWasStarted) {
locationEngine.removeLocationUpdates(locationCallback);
mapboxNavigation.removeProgressChangeListener(this);
mapboxNavigation.removeOffRouteListener(this);
mapboxNavigation.stopNavigation();
navigationWasStarted = false;
}
}
private void initDirectionsRoute() {
// Get route from predefined points.
NavigationRoute.builder(this)
.accessToken(getString(R.string.mapbox_access_token))
.origin(ROUTE_ORIGIN)
.destination(ROUTE_DESTINATION)
.build()
.getRoute(new Callback<DirectionsResponse>() {
@Override
public void onResponse(Call<DirectionsResponse> call, Response<DirectionsResponse> response) {
if (response.body() == null || response.body().routes().isEmpty()) {
return;
}
// Start navigation session with retrieved route.
DirectionsRoute route = response.body().routes().get(0);
mapboxNavigation.startNavigation(route);
// Set route progress.
VisionArManager.setRoute(new Route(
getRoutePoints(route),
route.duration().floatValue(),
"",
""
));
}
@Override
public void onFailure(Call<DirectionsResponse> call, Throwable t) {
}
});
}
@Override
public void onErrorReceived(Throwable throwable) {
if (throwable != null) {
throwable.printStackTrace();
}
mapboxNavigation.stopNavigation();
Toast.makeText(this, "Can not calculate the route requested", Toast.LENGTH_SHORT).show();
}
@Override
public void onResponseReceived(@NotNull DirectionsResponse response, RouteProgress routeProgress) {
mapboxNavigation.stopNavigation();
if (response.routes().isEmpty()) {
Toast.makeText(this, "Can not calculate the route requested", Toast.LENGTH_SHORT).show();
} else {
DirectionsRoute route = response.routes().get(0);
mapboxNavigation.startNavigation(route);
// Set route progress.
VisionArManager.setRoute(new Route(
getRoutePoints(route),
(float) routeProgress.durationRemaining(),
"",
""
));
}
}
@Override
public void onProgressChange(Location location, RouteProgress routeProgress) {
lastRouteProgress = routeProgress;
}
@Override
public void userOffRoute(Location location) {
routeFetcher.findRouteFromRouteProgress(location, lastRouteProgress);
}

private RoutePoint[] getRoutePoints(@NotNull DirectionsRoute route) {
ArrayList<RoutePoint> routePoints = new ArrayList<>();
List<RouteLeg> legs = route.legs();
if (legs != null) {
for (RouteLeg leg : legs) {
List<LegStep> steps = leg.steps();
if (steps != null) {
for (LegStep step : steps) {
RoutePoint point = new RoutePoint((new GeoCoordinate(
step.maneuver().location().latitude(),
step.maneuver().location().longitude()
)), mapToManeuverType(step.maneuver().type()));
routePoints.add(point);
List<Point> geometryPoints = buildStepPointsFromGeometry(step.geometry());
for (Point geometryPoint : geometryPoints) {
point = new RoutePoint((new GeoCoordinate(
geometryPoint.latitude(),
geometryPoint.longitude()
)), ManeuverType.None);
routePoints.add(point);
}
}
}
}
}
return routePoints.toArray(new RoutePoint[0]);
}
private List<Point> buildStepPointsFromGeometry(String geometry) {
return PolylineUtils.decode(geometry, Constants.PRECISION_6);
}
private ManeuverType mapToManeuverType(@Nullable String maneuver) {
if (maneuver == null) {
return ManeuverType.None;
}
switch (maneuver) {
case "turn":
return ManeuverType.Turn;
case "depart":
return ManeuverType.Depart;
case "arrive":
return ManeuverType.Arrive;
case "merge":
return ManeuverType.Merge;
case "on ramp":
return ManeuverType.OnRamp;
case "off ramp":
return ManeuverType.OffRamp;
case "fork":
return ManeuverType.Fork;
case "roundabout":
return ManeuverType.Roundabout;
case "exit roundabout":
return ManeuverType.RoundaboutExit;
case "end of road":
return ManeuverType.EndOfRoad;
case "new name":
return ManeuverType.NewName;
case "continue":
return ManeuverType.Continue;
case "rotary":
return ManeuverType.Rotary;
case "roundabout turn":
return ManeuverType.RoundaboutTurn;
case "notification":
return ManeuverType.Notification;
case "exit rotary":
return ManeuverType.RotaryExit;
default:
return ManeuverType.None;
}
}

Answer 1

在实例化此行时(即加载类时(：

private final Point ROUTE_ORIGIN=Point.fromLngLat(location.longitude(),location.latitude());

您正在使用的location变量设置为空：

public Point location;

阿卡，它是空的，你得到了一个NullPointerException。

在location对象实例化之前，您不应该尝试使用它，稍后设置routeOrigin。或者将ROUTE_ORIGIN更改为使用静态位置，与ROUTE_DESTINATION相同。