如果Kafka和Zookeeper没有运行，为什么Maven Clean Install无法完成？

为了学习Apache Kafka，我开发了一个Spring Boot应用程序，Kafka如果我将POST请求发送到调用KafkaTemplatesend方法的控制器，该应用程序会将消息发送到主题。我正在运行Ubuntu 19.04，并且已成功在本地安装Kafka和安装Zookeeper。一切正常。

当我关闭Zookeeper或时，就会发生问题Kafka。如果执行此操作，则在启动时Kafka AdminClient，我的应用程序会定期尝试查找信息，但将此消息发送到控制台

Connection to node -1 could not be established. Broker may not be available.

我实施了此处建议的修复程序Kafka + Zookeeper：无法建立到节点-1的连接。经纪人可能不可用，这里是Spring-Boot和Kafka：如何处理经纪人不可用？。但是，如果我跑maven clean install那么构建，如果无法完成Zookeeper，并Kafka没有运行。为什么会这样，并且有一种方法可以配置应用程序，以便Kafka在启动时检查可用性并在服务不可用时正常处理？

这是我的服务类别， KafkaTemplate

@Autowired
public PingMessageServiceImpl(KafkaTemplate kafkaTemplate, KafkaTopicConfiguration kafkaTopicConfiguration) {
    this.kafkaTemplate = kafkaTemplate;
    this.kafkaTopicConfiguration = kafkaTopicConfiguration;
}

@Override
public void sendMessage(String message) {
    log.info(String.format("Received following ping message %s", message));

    if (!isValidPingRequest(message)) {
        log.warn("Received invalid ping request");
        throw new InvalidPingRequestException();
    }
    log.info(String.format("Sending message=[%s]", message));
    ListenableFuture<SendResult<String, String>> future = kafkaTemplate.send(kafkaTopicConfiguration.getPingTopic(), message);
    future.addCallback(buildListenableFutureCallback(message));
}

private boolean isValidPingRequest(String message) {
    return "ping".equalsIgnoreCase(message);
}

private ListenableFutureCallback<SendResult<String, String>> buildListenableFutureCallback(String message) {
    return new ListenableFutureCallback<SendResult<String, String>>() {
        @Override
        public void onSuccess(SendResult<String, String> result) {
            log.info(String.format("Sent message=[%s] with offset=[%d]", message, result.getRecordMetadata().offset()));
        }
        @Override
        public void onFailure(Throwable ex) {
            log.info(String.format("Unable to send message=[%s] due to %s", message, ex.getMessage()));
        }
    };
}

这是我用来从属性文件中提取Kafka的配置属性的配置类

@NotNull(message = "bootstrapAddress cannot be null")
@NotBlank(message = "bootstrapAddress cannot be blank")
private String bootstrapAddress;

@NotNull(message = "pingTopic cannot be null")
@NotBlank(message = "pingTopic cannot be blank")
private String pingTopic;

@NotNull(message = "reconnectBackoffMs cannot be null")
@NotBlank(message = "reconnectBackoffMs cannot be blank")
@Value("${kafka.reconnect.backoff.ms}")
private String reconnectBackoffMs;

@Bean
public KafkaAdmin kafkaAdmin() {
    Map<String, Object> configurations = new HashMap<>();
    configurations.put(AdminClientConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapAddress);
    configurations.put(AdminClientConfig.RECONNECT_BACKOFF_MS_CONFIG, reconnectBackoffMs);
    return new KafkaAdmin(configurations);
}

@Bean
public NewTopic pingTopic() {
    return new NewTopic(pingTopic, 1, (short) 1);
}

@PostConstruct
private void displayOnStartup() {
    log.info(String.format("bootstrapAddress is %s", bootstrapAddress));
    log.info(String.format("reconnectBackoffMs is %s", reconnectBackoffMs));
}