Java Code Examples for java.util.Collections#emptyListIterator()

protected Iterator<Event> createEvents(LemmaSample sample) {

    if (sample != null) {
      List<Event> events = new ArrayList<Event>();
      String[] toksArray = sample.getTokens();
      String[] tagsArray = sample.getTags();
      String[] predsArray = sample.getLemmas();
      for (int ei = 0, el = sample.getTokens().length; ei < el; ei++) {
        events.add(new Event(predsArray[ei], contextGenerator.getContext(ei,toksArray,tagsArray,predsArray)));
      }
      return events.iterator();
    }
    else {
      return Collections.emptyListIterator();
    }
  }
 

/**
 * Used for exception example
 */
@SuppressWarnings("unused")
private void return_empty_list_iterator_java_exception () {

	DomainObject domain = null; // dao populate domain

	ListIterator<String> strings;
	if (domain != null && domain.getStrings() != null 
			&& domain.getStrings().hasNext()) {
		strings = domain.getStrings();
	} else {
		strings = Collections.emptyListIterator();
	}
	
	//...
}
 

public Iterator<IJV> getSparseBlockIterator(int rl, int ru) {
	//check for valid format, should have been checked from outside
	if( !sparse )
		throw new RuntimeException("getSparseBlockInterator should not be called for dense format");
	
	//check for existing sparse block: return empty list
	if( sparseBlock==null )
		return Collections.emptyListIterator();
	
	//get iterator over sparse block
	return sparseBlock.getIterator(rl, ru);
}
 

@Override
    public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
        initialized = false;
        this.context = context;

        // Spout internals
        this.collector = collector;
        numUncommittedOffsets = 0;

        // Offset management
        firstPollOffsetStrategy = kafkaSpoutConfig.getFirstPollOffsetStrategy();
        // with AutoCommitMode, offset will be periodically committed in the background by Kafka consumer
//        consumerAutoCommitMode = kafkaSpoutConfig.isConsumerAutoCommitMode();
        //永远设置为false
        consumerAutoCommitMode = false;

        // Retries management
        retryService = kafkaSpoutConfig.getRetryService();

        if (!consumerAutoCommitMode) {     // If it is auto commit, no need to commit offsets manually
            commitTimer = new Timer(TIMER_DELAY_MS, kafkaSpoutConfig.getOffsetsCommitPeriodMs(), TimeUnit.MILLISECONDS);
        }
        refreshSubscriptionTimer = new Timer(TIMER_DELAY_MS, kafkaSpoutConfig.getPartitionRefreshPeriodMs(), TimeUnit.MILLISECONDS);

        acked = new HashMap<>();
        emitted = new HashSet<>();
        waitingToEmit = Collections.emptyListIterator();

        LOG.info("Kafka Spout opened with the following configuration: {}", kafkaSpoutConfig);
    }
 

public Iterator<IJV> getSparseBlockIterator(int rl, int ru) {
	//check for valid format, should have been checked from outside
	if( !sparse )
		throw new RuntimeException("getSparseBlockInterator should not be called for dense format");
	
	//check for existing sparse block: return empty list
	if( sparseBlock==null )
		return Collections.emptyListIterator();
	
	//get iterator over sparse block
	return sparseBlock.getIterator(rl, ru);
}
 

@Override
public Iterator<Node> iterator() {

    if(nodes.isEmpty()) {
        return Collections.emptyListIterator();
    }

    final Node[] array = nodes.toArray(new Node[nodes.size()]);
    return new Iterator<Node>() {

        int i = 0;

        @Override
        public boolean hasNext() {
            return i < array.length;
        }

        @Override
        public Node next() {
            return array[i++];
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }

    };
}
 

public static void serializeServerMaintainedIndexes(PTable dataTable, ImmutableBytesWritable ptr,
        List<PTable> indexes, PhoenixConnection connection) {
    Iterator<PTable> indexesItr = Collections.emptyListIterator();
    boolean onlyLocalIndexes = dataTable.isImmutableRows() || dataTable.isTransactional();
    if (onlyLocalIndexes) {
        if (!dataTable.isTransactional()
                || !dataTable.getTransactionProvider().getTransactionProvider().isUnsupported(Feature.MAINTAIN_LOCAL_INDEX_ON_SERVER)) {
            indexesItr = maintainedLocalIndexes(indexes.iterator());
        }
    } else {
        indexesItr = maintainedIndexes(indexes.iterator());
    }

    serialize(dataTable, ptr, Lists.newArrayList(indexesItr), connection);
}
 

@Test
public void return_empty_list_iterator_java () {
	
	ListIterator<String> strings = Collections.emptyListIterator();

	assertFalse(strings.hasNext());
}