How to check if the Pubsub tutorial is running correctly?

edit

Hi I'm trying to learn the following pubsub tutorial code fragment but apparently, is still not connecting to roscore running on pc yet. The program installs successfully but there is no sign of a successful roscore connection.

/*******************************************************************/

/*
 * Copyright (C) 2011 Google Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package org.ros.tutorials.pubsub;

import org.ros.NodeConfiguration;
import org.ros.NodeRunner;
import org.ros.RosCore;
import org.ros.internal.node.address.InetAddressFactory;
import org.ros.rosjava.android.MessageCallable;
import org.ros.rosjava.android.views.RosTextView;

import android.app.Activity;
import android.os.Bundle;
/**
 * @author damonkohler@google.com (Damon Kohler)
 */

public class MainActivity extends Activity {

  private final NodeRunner nodeRunner;
  private RosCore rosCore;
  private RosTextView<org.ros.message.std_msgs.String> rosTextView;
  private Talker talker;

  public MainActivity() {
    super();
    nodeRunner = NodeRunner.createDefault();
  }

  @SuppressWarnings("unchecked")
  @Override

  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    rosTextView = (RosTextView<org.ros.message.std_msgs.String>) findViewById(R.id.text);
    rosTextView.setTopicName("/chatter");
    rosTextView.setMessageClass(org.ros.message.std_msgs.String.class);
    rosTextView.setMessageToStringCallable(new MessageCallable<String, org.ros.message.std_msgs.String>() {
          @Override
          public String call(org.ros.message.std_msgs.String message) {
            return message.data;
          }
        });
  }


  @Override
  protected void onPause() {
    super.onPause();
    talker.shutdown();
    rosTextView.shutdown();
    rosCore.shutdown();
  }

  @Override
  protected void onResume() {
    super.onResume();
    try {
      rosCore = RosCore.createPublic(11311);
      NodeConfiguration nodeConfiguration = NodeConfiguration.createDefault();
      nodeConfiguration.setHost(InetAddressFactory.createNonLoopback().getHostAddress());
      nodeRunner.run(rosCore, nodeConfiguration);
      rosCore.awaitStart();
      nodeConfiguration.setMasterUri(rosCore.getUri());
      talker = new Talker();
      nodeRunner.run(talker, nodeConfiguration);
      nodeRunner.run(rosTextView, nodeConfiguration);
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

}
/***********************End of Code*****************************/