計算路徑範例

您可以傳送 HTTP POST 要求至下列資源，從 Routes Preferred API 擷取一組路線：

https://routespreferred.googleapis.com/v1:computeRoutes

在訊息主體中加入以 JSON 格式編寫的要求選項。如要瞭解完整的選項集合，請參閱 computeRoutes 要求主體。

要求主體範例

下列 JSON 程式碼示範如何為 computeRoutes 要求建構一般要求主體。

POST /v1:computeRoutes
Host: routespreferred.googleapis.com
Content-Type: application/json
X-Goog-Api-Key: YOUR_API_KEY
X-Goog-FieldMask: routes.duration,routes.distanceMeters,routes.polyline.encodedPolyline

{
  "origin":{
    "location":{
      "latLng":{
        "latitude": 37.419734,
        "longitude": -122.0827784
      }
    }
  },
  "destination":{
    "location":{
      "latLng":{
        "latitude": 37.417670,
        "longitude": -122.079595
      }
    }
  },
  "travelMode": "DRIVE",
  "routingPreference": "TRAFFIC_AWARE",
  "polylineQuality": "OVERVIEW",
  "departureTime": "2019-10-15T15:01:23.045123456Z",
  "computeAlternativeRoutes": false,
  "routeModifiers": {
    "avoidTolls": false,
    "avoidHighways": false,
    "avoidFerries": false
  },
  "languageCode": "en-US",
  "units": "IMPERIAL"
}

回應主體範例

以下 JSON 程式碼是上述對 computeRoutes 呼叫傳回的回應主體範例。

{
  "routes": [
    {
      "distanceMeters": 772,
      "duration": "165s",
      "polyline": {
        "encodedPolyline": "ipkcFfichVnP@j@BLoFVwM{E?"
      }
    }
  ]
}

gRPC 要求範例

以下是 gRPC 要求範例。

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	routespreferred "developers.google.com/maps/go/routespreferred/v1"
	"google.golang.org/api/option"
	routespb "google.golang.org/genproto/googleapis/maps/routes/v1"
	"google.golang.org/genproto/googleapis/type/latlng"
	"google.golang.org/grpc/metadata"
)

const (
	// https://cloud.google.com/iam/docs/creating-managing-service-account-keys#creating_service_account_keys
	credentialsFile = "service-account.json"
	// Note that setting the field mask to * is OK for testing, but discouraged in
	// production.
	// For example, for ComputeRoutes, set the field mask to
	// "routes.distanceMeters,routes.duration,routes.polyline.encodedPolyline"
	// in order to get the route distances, durations, and encoded polylines.
	fieldMask = "*"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	// instantiate a client
	c, err := routespreferred.NewRoutesPreferredClient(ctx,
		option.WithCredentialsFile(credentialsFile))
	defer c.Close()

	if err != nil {
		log.Fatal(err)
	}

	// create the origin using a latitude and longitude
	origin := &routespb.Waypoint{
		LocationType: &routespb.Waypoint_Location{
			Location: &routespb.Location{
				LatLng: &latlng.LatLng{
					Latitude:  37.417670,
					Longitude: -122.0827784,
				},
			},
		},
	}

	// create the destination using a latitude and longitude
	destination := &routespb.Waypoint{
		LocationType: &routespb.Waypoint_Location{
			Location: &routespb.Location{
				LatLng: &latlng.LatLng{
					Latitude:  37.417670,
					Longitude: -122.079595,
				},
			},
		},
	}

	// create the request with additional options
	req := &routespb.ComputeRoutesRequest{
		Origin:                   origin,
		Destination:              destination,
		TravelMode:               routespb.RouteTravelMode_DRIVE,
		RoutingPreference:        routespb.RoutingPreference_TRAFFIC_AWARE,
		ComputeAlternativeRoutes: true,
		Units:                    routespb.Units_METRIC,
		LanguageCode:             "en-us",
		RouteModifiers: &routespb.RouteModifiers{
			AvoidTolls:    false,
			AvoidHighways: true,
			AvoidFerries:  true,
		},
		PolylineQuality: routespb.PolylineQuality_OVERVIEW,
	}

	// set the field mask
	ctx = metadata.AppendToOutgoingContext(ctx, "X-Goog-Fieldmask", fieldMask)

	// execute rpc
	resp, err := c.ComputeRoutes(ctx, req)

	if err != nil {
		// "rpc error: code = InvalidArgument desc = Request contains an invalid
		// argument" may indicate that your project lacks access to Routes Preferred
		log.Fatal(err)
	}

	fmt.Printf("Duration of route %d", resp.Routes[0].Duration.Seconds)
}
main.go

以下範例使用 computeRoutes 方法，在使用通行卡時傳回含有預估價格的通行費資訊。

這項功能會透過要求中指定的 routes.travelAdvisory.tollInfo 欄位遮罩啟用。通行費通行證會在 route_modifiers 欄位中指定。系統會根據指定通行證使用的價格，傳回通行費價格。如果指定多個通行證，系統會傳回最便宜的價格。

要求：

curl -X POST -d '{
  "origin":{
    "location":{
      "lat_lng":{
        "latitude":47.7020056,
        "longitude":-122.3479236
      }
    }
  },
  "destination":{
    "location":{
      "lat_lng":{
        "latitude":47.6192234,
        "longitude": -122.1676792
      }
    }
  },
  "travel_mode":"DRIVE",
  "route_modifiers":{
    "vehicle_info":{
      "emission_type": "GASOLINE"
    },
    "toll_passes": [
      "US_MA_EZPASSMA",
      "US_WA_GOOD_TO_GO"
    ]
  }
}' \
-H 'Content-Type: application/json' \
-H 'X-Goog-Api-Key: <YOUR_API_KEY>' \
-H 'X-Goog-FieldMask: routes.duration,routes.distanceMeters,routes.travelAdvisory.tollInfo,routes.legs.travelAdvisory.tollInfo' \
'https://routespreferred.googleapis.com/v1alpha:computeRoutes'

回應：

{
  "routes": [
    {
      "legs": [
        {
          "travelAdvisory": {
            "tollInfo": {
              "estimatedPrice": [
                {
                  "currencyCode": "USD",
                  "units": "3",
                  "nanos": 400000000
                }
              ]
            }
          }
        }
      ],
      "distanceMeters": 22496,
      "duration": "1400s",
      "travelAdvisory": {
        "tollInfo": {
          "estimatedPrice": [
            {
              "currencyCode": "USD",
              "units": "3",
              "nanos": 400000000
            }
          ]
        }
      }
    }
  ]
}