Question

我知道这个问题非常普遍，但是按照不同的解决方案，我找不到任何可行的解决方案。在Kafka中接收消息时，我想反序列化字符串以及我的自定义类对象。使用String会很好，但不能使用我的Class。我在使用者配置中添加了受信任的程序包（其中com.springmiddleware.entities是我的课程所在的程序包）：

@Bean
    public Map<String, Object> consumerConfigs() {


        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "foo");
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        props.put(JsonDeserializer.TRUSTED_PACKAGES, "com.springmiddleware.entities");

        return props;
    }

我的application.yml文件中有这个文件：

spring:
kafka:
    bootstrap-servers: localhost:9092
    consumer:
      group-id: foo
      auto-offset-reset: earliest
      value-deserializer: org.springframework.kafka.support.serializer.JsonDeserializer
      properties:
        spring:
          json:
            trusted:
              packages: 'com.springmiddleware.entities'

并将这些行添加到application.properties

spring.kafka.consumer.value-deserializer=org.springframework.kafka.support.serializer.JsonDeserializer
spring.kafka.consumer.properties.spring.json.trusted.packages=com.springmiddleware.entities
spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer 
spring.kafka.producer.properties.spring.json.add.type.headers=false

但是仍然显示以下错误：

org.apache.kafka.common.errors.SerializationException：错误在偏移量1处将分区topic2-0的键/值反序列化。如果需要，请查找过去的记录以继续消费。造成原因： java.lang.IllegalArgumentException：此类 “ com.springmiddleware.entities.Crime”不在受信任的软件包中： [java.util，java.lang]。如果您认为本课程安全，反序列化，请提供其名称。如果仅序列化由受信任的来源完成，您还可以启用全部信任（*）。

更新

ReceiverConfig：

@EnableKafka
@Configuration
public class ReceiverConfig {

    @Value("${spring.kafka.bootstrap-servers}")
    private String bootstrapServers;

    @Bean
    public Map<String, Object> consumerConfigs() {


        Map<String, Object> props = new HashMap<>();
        props.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
        props.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, StringDeserializer.class);
        props.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, JsonDeserializer.class);
        props.put(ConsumerConfig.GROUP_ID_CONFIG, "foo");
        props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
        props.put(JsonDeserializer.TRUSTED_PACKAGES, "com.springmiddleware.entities");
        props.put(JsonDeserializer.USE_TYPE_INFO_HEADERS, "false");
        return props;
    }

    @Bean
    public ConsumerFactory<String, Object> consumerFactory() {
        return new DefaultKafkaConsumerFactory<>(consumerConfigs(),  new StringDeserializer(),
                new JsonDeserializer<>());
    }

    @Bean
    public KafkaListenerContainerFactory<ConcurrentMessageListenerContainer<String, Object>> kafkaListenerContainerFactory() {
        ConcurrentKafkaListenerContainerFactory<String, Object> factory = new ConcurrentKafkaListenerContainerFactory<>();
        factory.setConsumerFactory(consumerFactory());
        return factory;
    }

更新2

Listener Class (Receiver): 

    @KafkaListener(topics = "${app.topic.foo}")
@Service
public class Receiver {


     private CountDownLatch latch = new CountDownLatch(1);

        public CountDownLatch getLatch() {
            return latch;
        }

   @KafkaHandler
    public void listen(@Payload Crime message) {

            System.out.println("Received " + message);
    }

   @KafkaHandler
    public void listen(@Payload String message) {

        System.out.println("Received " +  message);
}

Answer 1

只需使用重载的JsonDeserializer构造函数

从2.2版开始，您可以使用具有boolean useHeadersIfPresent（默认为true）的重载构造函数之一，将反序列化器显式配置为使用提供的目标类型并忽略标头中的类型信息。

以下示例显示了如何执行此操作：

DefaultKafkaConsumerFactory<Integer, Cat1> cf = new DefaultKafkaConsumerFactory<>(props,
    new IntegerDeserializer(), new JsonDeserializer<>(Cat1.class, false));

您的代码：

@Bean
public ConsumerFactory<String, Object> consumerFactory() {
    return new DefaultKafkaConsumerFactory<>(consumerConfigs(),  new StringDeserializer(),
            new JsonDeserializer<>(Object.class,false));
}

现在在班级使用@KafkaListener

@KafkaListener(topics = "myTopic")
@Service
public class MultiListenerBean {

@KafkaHandler
public void listen(Cat cat) {
    ...
}

@KafkaHandler
public void listen(Hat hat) {
    ...
}

@KafkaHandler(isDefault = true)
public void delete(Object obj) {
    ...
   }

}

Spring Boot Kafka类反序列化-不在受信任的程序包中

1 个答案: