Lost thread statement in the background

package app.z0nen.slidemenu;

import android.app.Activity;
import android.app.Fragment;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.MalformedInputException;

/**
 * Created by Z0NEN
 */
public class menu1_Fragment extends Fragment {
    View rootview;
    EditText editIp;
    Button btnOn, btnOff;
    TextView textInfo1, textInfo2;
    // private View.OnClickListener btnOnOffClickListener;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        rootview = inflater.inflate(R.layout.menu1_layout, container, false);
        return rootview;
    }

    public void addListenerOnButton(View rootview) {
        editIp = (EditText) rootview.findViewById(R.id.ip);
        btnOn = (Button) rootview.findViewById(R.id.bon);
        btnOff = (Button) rootview.findViewById(R.id.boff);
        textInfo1 = (TextView) getView().findViewById(R.id.info1);
        textInfo2 = (TextView) getView().findViewById(R.id.info2);

        btnOn.setOnClickListener((View.OnClickListener) this);
        btnOff.setOnClickListener((View.OnClickListener) this);
    }

    public View.OnClickListener btnOnOffClickListener = new View.OnClickListener() {
        public void onClick(View rootview) {
            String onoff;
            if (rootview == btnOn) {
                onoff = "/on";
            } else {
                onoff = "/off";
            }

            btnOn.setEnabled(false);
            btnOff.setEnabled(false);

            String serverIP = editIp.getText().toString() + onoff;

            TaskEsp taskEsp = new TaskEsp(serverIP);
            taskEsp.execute();
        }
    };

    private class TaskEsp extends AsyncTask<Void, Void, String>{
        String server;

        TaskEsp(String server){ this.server = server;}


        protected String doInBackground(Void... params){
            final String p = "http://"+server;


           getActivity().runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    textInfo1.setText(p);
                }
            });

            String serverResponse = "";
            //Using java.net.HttpURLConnection
            try{
                HttpURLConnection httpURLConnection = (
                HttpURLConnection)(new URL(p).openConnection());

                if(httpURLConnection.getResponseCode()== HttpURLConnection.HTTP_OK){

                    InputStream inputStream = null;
                    inputStream = httpURLConnection.getInputStream();
                    BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                    serverResponse = bufferedReader.readLine();

                    inputStream.close();
                }
            }catch (MalformedInputException e){
                e.printStackTrace();
                serverResponse = e.getMessage();
            }catch (IOException e){
                e.printStackTrace();
                serverResponse = e.getMessage();
            }
            return serverResponse;
        }



        @Override
        protected void onPostExecute(String s){
            textInfo2.setText(s);
            btnOn.setEnabled(true);
            btnOff.setEnabled(true);
        }
    }

}