I Can't Return Response Body Synchronous GET with OkHttp Android Studio

Question

I try on this code but it is not work.

I'm trying to create code like the one below, but I couldn't.

I would like to assign the returned value from this code to a String value in MainActivity.

public class Client {

OkHttpClient client = new OkHttpClient();

public String getHttpBody(String url) throws IOException {
    Request request = new Request.Builder().url(url).build();
    Call call = client.newCall(request);
    Response response = call.execute();
    return response.body().string();
 }
}