### Question:
KafkaAdminClient implements Closeable { public void deleteTopic(String topic) { if (StringUtils.isBlank(topic)) throw new IllegalArgumentException("topic cannot be null, empty or blank"); LOG.debug("Deleting topic [{}]", topic); try { getNewAdminClient().deleteTopics(Collections.singleton(topic)).all().get(operationTimeout, TimeUnit.MILLISECONDS); long start = System.currentTimeMillis(); boolean operationCompleted = false; do { LOG.debug("Sleeping for {} ms for delete topic operation to complete for topic [{}]", operationSleep, topic); try { Thread.sleep(operationSleep); } catch (InterruptedException e) { throw new AdminOperationException("Interrupted waiting for topic " + topic + " to be deleted", e); } operationCompleted = !topicExists(topic); } while (!operationCompleted && !operationTimedOut(start)); if (!operationCompleted) throw new AdminOperationException("Timeout waiting for topic " + topic + " to be deleted"); } catch (InterruptedException | ExecutionException | TimeoutException e) { Throwable throwable = e.getCause(); if (throwable instanceof UnknownTopicOrPartitionException) { LOG.warn("Topic [{}] to be deleted was not found", topic, e); } else { throw new AdminOperationException("Unable to delete topic: " + topic, e); } } } KafkaAdminClient(Properties properties); Set<String> getTopics(); Set<TopicAndPartition> getPartitions(); Set<TopicAndPartition> getPartitions(String topic); Authorizer getAuthorizer(); Map<Resource, Set<Acl>> getAcls(); Map<Resource, Set<Acl>> getAcls(KafkaPrincipal principal); Set<Acl> getAcls(Resource resource); void addAcls(Set<Acl> acls, Resource resource); void removeAcls(Set<Acl> acls, Resource resource); void createTopic(String topic, int partitions, int replicationFactor); void createTopic(String topic, int partitions, int replicationFactor, Properties topicConfig); void deleteTopic(String topic); Properties getTopicConfig(String topic); void updateTopicConfig(String topic, Properties properties); int getTopicReplicationFactor(String topic); int getTopicPartitions(String topic); void addTopicPartitions(String topic, int partitions); AdminClient.ConsumerGroupSummary getConsumerGroupSummary(String consumerGroup); Collection<AdminClient.ConsumerSummary> getConsumerGroupSummaries(String consumerGroup); Map<TopicPartition, String> getConsumerGroupAssignments(String consumerGroup); @Override void close(); static final String ZOOKEEPER_SECURE; static final String DEFAULT_ZOOKEEPER_SECURE; static final String OPERATION_TIMEOUT_MS; static final String DEFAULT_OPERATION_TIMEOUT_MS; static final String OPERATION_SLEEP_MS; static final String DEFAULT_OPERATION_SLEEP_MS; }### Answer:
@Test public void deleteTopic() { client.createTopic(topic, 1, 1); assertThat(client.getTopics(), hasItem(topic)); client.deleteTopic(topic); assertThat(client.getTopics(), not(hasItem(topic))); }
@Test public void deleteTopic_doesNotExist() { client.deleteTopic("does_not_exist"); }
@Test (expected = IllegalArgumentException.class) public void deleteTopic_nullTopic() { client.deleteTopic(null); }
@Test (expected = IllegalArgumentException.class) public void deleteTopic_emptyTopic() { client.deleteTopic(""); }