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

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

public class MainActivity extends AppCompatActivity {

    private TextView responseTextView;

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

        responseTextView = findViewById(R.id.response_text_view);

        // JAX-RS 웹 서비스의 URL
        String serviceUrl = "http://example.com/api/data";

        // 웹 서비스에 GET 요청 보내는 AsyncTask 실행
        new RequestTask().execute(serviceUrl);
    }

    private class RequestTask extends AsyncTask<String, Void, String> {

        @Override
        protected String doInBackground(String... urls) {
            String response = "";
            HttpClient httpClient = new DefaultHttpClient();
            HttpGet httpGet = new HttpGet(urls[0]);

            try {
                HttpResponse httpResponse = httpClient.execute(httpGet);
                response = EntityUtils.toString(httpResponse.getEntity());
            } catch (Exception e) {
                e.printStackTrace();
            }

            return response;
        }

        @Override
        protected void onPostExecute(String result) {
            responseTextView.setText(result);
        }
    }
}