When using Retrofit 2 to call an API and you want to handle JSON data, you can use the GsonConverterFactory to serialize and deserialize JSON data. Here's how you can add it to your Retrofit setup:
1. First, make sure you have added the Retrofit and Gson dependencies to your project. You can do this by including the following lines in your app-level `build.gradle` file:
```gradle
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'
```
Ensure you use the appropriate version of Retrofit and Gson for your project.
2. Create a Retrofit instance with the GsonConverterFactory added. Typically, you would set up your Retrofit instance like this:
```java
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("https://api.example.com/") // Your base API URL
.addConverterFactory(GsonConverterFactory.create())
.build();
```
3. Define your API service interface and use the Retrofit instance to create an implementation of it:
```java
import retrofit2.Call;
import retrofit2.http.GET;
public interface ApiService {
@GET("endpoint") // Define your API endpoint here
Call<YourResponseModel> getSomeData();
}
// Create an instance of the API service
ApiService apiService = retrofit.create(ApiService.class);
```
4. Now you can make API calls using the service methods. For example:
```java
Call<YourResponseModel> call = apiService.getSomeData();
call.enqueue(new Callback<YourResponseModel>() {
@Override
public void onResponse(Call<YourResponseModel> call, Response<YourResponseModel> response) {
if (response.isSuccessful()) {
// Handle the successful response here
YourResponseModel data = response.body();
} else {
// Handle the error response
}
}
@Override
public void onFailure(Call<YourResponseModel> call, Throwable t) {
// Handle network errors or failures here
}
});
```
This setup uses the GsonConverterFactory to automatically serialize and deserialize JSON data for your API calls. Make sure to replace `YourResponseModel` with your actual response model class.