我正在使用spring-kafka 2.1.7来使用JSON消息,并且我想处理无法正确反序列化的消息。
为了覆盖遍历同一条消息的默认行为,我扩展了JsonDeserializer来覆盖deserialize方法。
public class CustomKafkaJsonDeserializer<T> extends JsonDeserializer<T> {
public CustomKafkaJsonDeserializer(Class<T> targetType) {
super(targetType);
this.objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, true);
}
@Override
public T deserialize(String topic, byte[] data) {
try {
return super.deserialize(topic, data);
} catch (Exception e) {
log.error("Problem deserializing data " + new String(data) + " on topic " + topic, e.getMessage());
return null;
}
}
}
这是我的使用者及其配置:
@Service
public class Consumer {
@KafkaListener(topics = "${kafka.topic.out}", containerFactory = "kafkaListenerContainerFactory", errorHandler = "customKafkaListenerErrorHandler")
public void consume(@Payload Lines lines, @Headers MessageHeaders messageHeaders) {
//treatment
}
}
@Configuration
public class ConsumerConfig {
...
@Bean
public ConsumerFactory<String, Lines> consumerFactory() {
return new DefaultKafkaConsumerFactory<>(consumerConfigs(), new StringDeserializer(), new CustomKafkaJsonDeserializer<>(Lines.class));
}
@Bean
public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<String, Lines>> kafkaListenerContainerFactory() {
ConcurrentKafkaListenerContainerFactory<String, Lines> factory = new ConcurrentKafkaListenerContainerFactory<>();
factory.setConsumerFactory(consumerFactory());
return factory;
}
private Map<String, Object> consumerConfigs() {
Map<String, Object> props = new HashMap<>();
props.put("bootstrap.servers", this.bootstrapServers);
props.put("group.id", this.appName);
props.put("key.deserializer", StringDeserializer.class);
props.put("value.deserializer", CustomKafkaJsonDeserializer.class);
props.put("security.protocol", this.securityProtocol);
props.put("sasl.mechanism", this.saslMechanism);
props.put("sasl.jaas.config", this.saslJaasConfig);
return props;
}
}
最后,我实现了自己的错误处理程序,以便将错误的数据发送到另一个主题。
@Component
public class CustomKafkaListenerErrorHandler implements KafkaListenerErrorHandler {
@Autowired
private KafkaErrorService kafkaErrorService;
@Override
public Object handleError(Message<?> message, ListenerExecutionFailedException exception) throws Exception {
log.error("error handler for message: {} [{}], exception: {}", message.getPayload(), message.getHeaders(), exception.getMessage());
kafkaErrorService.sendErrorToKafka(message.getPayload().toString(), exception.getMessage());
throw new RuntimeException(exception);
}
}
这是我收到错误消息时发生的事情:
关于如何实现此目标的任何建议?
答案 0 :(得分:0)
返回包含数据和标头的丰富对象,而不是返回null。