如何使用 Google Maps API v2 获取路线规划行车路线？

import com.akexorcist.googledirection.DirectionCallback;
import com.akexorcist.googledirection.GoogleDirection;
import com.akexorcist.googledirection.model.Direction;
import com.akexorcist.googledirection.model.Leg;
import com.akexorcist.googledirection.model.Route;
import com.akexorcist.googledirection.util.DirectionConverter;

...

// Replace with your API key
String apiKey = "YOUR_API_KEY";

GoogleDirection.withServerKey(apiKey)
        .from(new LatLng(12.917745600000000000,77.623788300000000000))
        .to(new LatLng(12.842056800000000000,7.663096499999940000))
        .execute(new DirectionCallback() {
            @Override
            public void onDirectionSuccess(Direction direction, String rawBody) {
                if (direction.isOK()) {
                    Route route = direction.getRouteList().get(0);
                    Leg leg = route.getLegList().get(0);
                    
                    // Draw the path (Polylines)
                    List<LatLng> directionPositionList = DirectionConverter.decodePoly(leg.getPolylinePoint());
                    Polyline line = mMap.addPolyline(new PolylineOptions()
                            .addAll(directionPositionList)
                            .width(5)
                            .color(Color.RED));
                    
                    // Display turn-by-turn instructions
                    String[] instructions = DirectionConverter.provideInstructionList(leg);
                    for (String instruction : instructions) {
                        Log.d("Direction", instruction);
                    }
                } else {
                    // Handle error
                }
            }

            @Override
            public void onDirectionFailure(Throwable t) {
                // Handle error
            }
        });