[Android] Retrofit library

compile 'com.google.code.gson:gson:2.6.2'
compile 'com.squareup.retrofit2:retrofit:2.0.2'
compile 'com.squareup.retrofit2:converter-gson:2.0.2'



public class ApiClient {
    public static final String BASE_URL = "your URL";
    private static Retrofit retrofit = null;

    public static Retrofit getClient() {
        if (retrofit == null) {
            retrofit = new Retrofit.Builder()
                    .baseUrl(BASE_URL)
                    .addConverterFactory(GsonConverterFactory.create())
                    .build();
        }
        return retrofit;
    }
}

public interface ApiInterface {
    @GET("Retrofit.php")
    Call<List<Message>> getInbox();
}

public class Message {
    public int id;
    public String msg;
    public String url;

    public Message(int id, String msg, String url) {
        this.id = id;
        this.msg = msg;
        this.url = url;
    }
}

public class MainActivity extends AppCompatActivity {
    String TAG = "MainActivity";
    @Override    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ApiInterface apiService = ApiClient.getClient().create(ApiInterface.class);
        Call<List<Message>> call = apiService.getInbox();
        call.enqueue(new Callback<List<Message>>() {
            @Override
            public void onResponse(Call<List<Message>> call, Response<List<Message>> response) {
                // TODO - avoid looping
                List<Message> messageList = response.body();
                for (Message message : messageList) {
                    Log.d(TAG, new Gson().toJson(message));
                }
            }
            @Override
            public void onFailure(Call<List<Message>> call, Throwable t) {
                Toast.makeText(getApplicationContext(), "Unable to fetch json: " + t.getMessage(), Toast.LENGTH_LONG).show();
            }
        });
    }
}

    }
}