Google Pub / Sub Java Examples

I cannot find a way to read posts from pub / sub using java.

I am using this maven dependency in my pom

<dependency>
  <groupId>com.google.cloud</groupId>
  <artifactId>google-cloud-pubsub</artifactId>
  <version>0.17.2-alpha</version>
</dependency>

      

        
        
        
      

    

I followed this basic method to create a new theme:

public static void main(String... args) throws Exception {

        // Your Google Cloud Platform project ID
        String projectId = ServiceOptions.getDefaultProjectId();

        // Your topic ID
        String topicId = "my-new-topic-1";
        // Create a new topic
        TopicName topic = TopicName.create(projectId, topicId);
        try (TopicAdminClient topicAdminClient = TopicAdminClient.create()) {
            topicAdminClient.createTopic(topic); 
        }
}

      

        
        
        
      

    

The above code works well and indeed I can see a new theme generated using google cloud console.

I have applied the following main method for writing a post in my topic:

public static void main(String a[]) throws InterruptedException, ExecutionException{
        String projectId = ServiceOptions.getDefaultProjectId(); 
        String topicId = "my-new-topic-1";

        String payload = "Hellooooo!!!";
        PubsubMessage pubsubMessage =
                  PubsubMessage.newBuilder().setData(ByteString.copyFromUtf8(payload)).build();

        TopicName topic = TopicName.create(projectId, topicId);

        Publisher publisher;
        try {
            publisher = Publisher.defaultBuilder(
                    topic)
                    .build();
            publisher.publish(pubsubMessage);

            System.out.println("Sent!");
        } catch (IOException e) {
            System.out.println("Not Sended!");
            e.printStackTrace();
        }
}

      

        
        
        
      

    

Now I cannot verify if this message was actually sent. I would like to implement a message reader using a subscription to my topic. Can anyone show me a correct and working java example about reading posts from a topic?

Can anyone help me? Thanks in advance!