OkHttp3 asyncTask example

MainActivity.java

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final TextView textView = (TextView) findViewById(R.id.textView);

        final OkHttpClient client = new OkHttpClient();

        final Request request = new Request.Builder()
                .url("http://www.mocky.io/v2/573336c90f0000902cead88d")
                .build();

        AsyncTask<Void, Void, String> asyncTask = new AsyncTask<Void, Void, String>() {
            @Override
            protected String doInBackground(Void... params) {
                try {
                    Response response = client.newCall(request).execute();
                    if (!response.isSuccessful()) {
                        return null;
                    }
                    return response.body().string();
                } catch (Exception e) {
                    e.printStackTrace();
                    return null;
                }
            }

            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                if (s != null) {
                    textView.setText(s);
                }
            }
        };

        asyncTask.execute();
    }

}