How to Access Google Maps Elevation API in Android Apps

Integrate Google Maps Elevation API in Android Application

• Ensure you have included Google Maps dependency in your `build.gradle` file. It's essential for accessing Google Maps SDK features that link with the Elevation API.

 

• By using Retrofit, a type-safe HTTP client for Android, you can easily interact with Google's APIs. Add the necessary dependencies for Retrofit in your `build.gradle` file.

implementation 'com.squareup.retrofit2:retrofit:2.9.0'  
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'  

Set Up Retrofit for Elevation API

• Create an interface for the Elevation API endpoints. The `getElevation` function will define the request to the API. Ensure you pass the correct `latlng` parameter, representing the latitude and longitude of the location you need the elevation for.

public interface ElevationService {  
    @GET("/maps/api/elevation/json")  
    Call<ElevationResponse> getElevation(@Query("locations") String locations,  
                                         @Query("key") String apiKey);  
}

• Next, configure Retrofit to create an instance of the `ElevationService`.

Retrofit retrofit = new Retrofit.Builder()  
        .baseUrl("https://maps.googleapis.com")  
        .addConverterFactory(GsonConverterFactory.create())  
        .build();  

ElevationService service = retrofit.create(ElevationService.class);  

Invoke the API and Handle Responses

• Formulate a function within your activity or service to call the `getElevation` method, providing the latitude, longitude, and your Google API key. Handle the API response to extract elevation data.

public void fetchElevation(String latLng) {  
    Call<ElevationResponse> call = service.getElevation(latLng, "YOUR_API_KEY");  
    call.enqueue(new Callback<ElevationResponse>() {  
        @Override  
        public void onResponse(Call<ElevationResponse> call,  
                               Response<ElevationResponse> response) {  
            if (response.isSuccessful()) {  
                // Parse the response to get elevation  
                double elevation = response.body().getResults().get(0).getElevation();  
                Log.d("Elevation API", "Elevation: " + elevation);  
            }  
        }  
  
        @Override  
        public void onFailure(Call<ElevationResponse> call, Throwable t) {  
            Log.e("Elevation API", "Error: " + t.getMessage());  
        }  
    });  
}

Parse and Use the Elevation Data

• Create a model class for the JSON response using Gson library annotations, allowing Retrofit to transform JSON data into usable objects.

public class ElevationResponse {  
    private List<Result> results;  

    public List<Result> getResults() {  
        return results;  
    }  

    public class Result {  
        private double elevation;  

        public double getElevation() {  
            return elevation;  
        }  
    }  
}

• Once parsed, you can utilize this elevation data in your app's functionalities, such as for informing users or integrating into geographic calculations.