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.
