Retrofit 2 Api Client Class

Retrofit2ApiClient.java

import okhttp3.OkHttpClient;
import okhttp3.logging.HttpLoggingInterceptor;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

public class ApiClient {

    private static Retrofit retrofit = null;

    private static OkHttpClient buildClient() {
        return new OkHttpClient
                .Builder()
                .addInterceptor(new HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY))
                .build();
    }

    public static Retrofit getClient() {
        if (retrofit == null) {
            retrofit = new Retrofit.Builder()
                    .client(buildClient())
                    .addConverterFactory(GsonConverterFactory.create())
                    .baseUrl("http://xyz.xyz")
                    .build();
        }

        return retrofit;
    }

}

/*
Inside "build.gradle" file:

dependencies {
    // ...
    // ...
    // ...

    implementation 'com.squareup.retrofit2:retrofit:2.5.0'
    implementation 'com.squareup.retrofit2:converter-gson:2.5.0'

    implementation 'com.squareup.okhttp3:logging-interceptor:3.11.0'
}
*/