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spring-boot - Spring Cloud Stream 反序列化来自 Kafka 主题的无效 JSON

问题描述

我正在努力将 Spring Cloud Streams 与 Kafka binder 集成。目标是我的应用程序使用主题中的 json 并将其反序列化为 Java 对象。我正在使用功能样式方法而不是命令式方法。我的代码使用结构良好的 json 输入。

另一方面，当我发送无效的 json 时，我希望触发错误记录方法。这在某些测试用例中有效，而在其他测试用例中无效。我的应用程序对 json 进行反序列化，即使它无效并触发包含逻辑的方法，而不是错误记录方法。

我无法解决为什么框架反序列化一些非结构化 json 输入的问题。

@Builder
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class KafkaEventRecord {

    @JsonProperty(value = "transport_metadata", required = true)
    @NonNull
    private TransportMetadata transportMetadata;

    @JsonProperty(value = "payload", required = true)
    @NonNull
    private Payload payload;
}



@Component
public class TokenEventConsumer {

    @Bean
    Consumer<KafkaEventRecord> consumer() {
        return event -> {
            log.info("Kafka Event data consumed from Kafka {}", event);
        };
    }
}


@Configuration
@Slf4j
public class CloudStreamErrorHandler {

    @ServiceActivator(inputChannel = "errorChannel")
    public void handleError(ErrorMessage errorMessage) {
            log.error("Error Message is {}", errorMessage);
    }
}


@EmbeddedKafka(topics = {"batch-in"}, partitions = 3)
@TestPropertySource(properties = {"spring.kafka.producer.bootstrap-servers=${spring.embedded.kafka.brokers}",
        "spring.kafka.consumer.bootstrap-servers=${spring.embedded.kafka.brokers}",
        "spring.cloud.stream.kafka.binder.brokers=${spring.embedded.kafka.brokers}"})
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
@ActiveProfiles("test")
@Slf4j
public class KafkaTokenConsumerTest {

    private static String TOPIC = "batch-in";

    @Autowired
    private EmbeddedKafkaBroker embeddedKafkaBroker;

    @Autowired
    private KafkaTemplate<String, String> kafkaTemplate;

    @Autowired
    private KafkaListenerEndpointRegistry endpointRegistry;

    @Autowired
    private ObjectMapper objectMapper;

    @SpyBean
    KafkaEventHandlerFactory kafkaEventHandlerFactory;

    @SpyBean
    CloudStreamErrorHandler cloudStreamErrorHandler;


    @BeforeEach
    void setUp() {
        for (MessageListenerContainer messageListenerContainer : endpointRegistry.getListenerContainers()) {
            ContainerTestUtils.waitForAssignment(messageListenerContainer, embeddedKafkaBroker.getPartitionsPerTopic());
        }
    }

    // THIS METHOD PASSES
    @Test
    public void rejectCorruptedMessage() throws ExecutionException, InterruptedException {

        kafkaTemplate.send(TOPIC, "{{{{").get(); // synchronous call

        CountDownLatch latch = new CountDownLatch(1);
        latch.await(5L, TimeUnit.SECONDS);

        // The frame works tries two times, no idea why
        verify(cloudStreamErrorHandler, times(2)).handleError(isA(ErrorMessage.class));

    }

    // THIS METHOD FAILS
    @Test
    public void rejectCorruptedMessage2() throws ExecutionException, InterruptedException {

        kafkaTemplate.send(TOPIC, "{}}}").get(); // synchronous call

        CountDownLatch latch = new CountDownLatch(1);
        latch.await(5L, TimeUnit.SECONDS);

        // The frame works tries two times, no idea why
        verify(cloudStreamErrorHandler, times(2)).handleError(isA(ErrorMessage.class));

    }
}

spring.cloud.stream.kafka.bindings.consumer-in-0.consumer.configuration.spring.deserializer.key.delegate.class=org.apache.kafka.common.serialization.StringDeserializer
spring.cloud.stream.kafka.bindings.consumer-in-0.consumer.configuration.spring.deserializer.value.delegate.class=org.springframework.kafka.support.serializer.JsonDeserializer
spring.cloud.stream.kafka.bindings.consumer-in-0.consumer.configuration.key.deserializer=org.springframework.kafka.support.serializer.ErrorHandlingDeserializer
spring.cloud.stream.kafka.bindings.consumer-in-0.consumer.configuration.value.deserializer=org.springframework.kafka.support.serializer.ErrorHandlingDeserializer

// Producer only for testing purpose
spring.kafka.producer.key-serializer=org.apache.kafka.common.serialization.StringSerializer
spring.kafka.producer.value-serializer=org.springframework.kafka.support.serializer.JsonSerializer

rejectCorruptedMessage测试方法中的json ，triggershandleError(ErrorMessage errorMessage)方法，这是预期的，因为它是无效的json。另一方面，rejectCorruptedMessage2测试方法中的 json 触发Consumer<KafkaEventRecord> consumer()了 TokenEventConsumer 类中的方法，这不是预期的行为，但是，我得到了具有空值的 KafkaEventRecord 对象。

标签： spring-bootapache-kafkaspring-cloud-streamembedded-kafka

解决方案

Jackson 不认为这是无效的 JSON，它只是忽略尾随}}并将其解码{}为空对象。

public class So67804599Application {

    public static void main(String[] args) throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        JavaType type = mapper.constructType(Foo.class);
        Object foo = mapper.readerFor(Foo.class).readValue("{\"bar\":\"baz\"}");
        System.out.println(foo);
        foo = mapper.readerFor(Foo.class).readValue("{}}}");
        System.out.println(foo);
    }

    public static class Foo {

        String bar;

        public String getBar() {
            return this.bar;
        }

        public void setBar(String bar) {
            this.bar = bar;
        }

        @Override
        public String toString() {
            return "Foo [bar=" + this.bar + "]";
        }

    }

}

Foo [bar=baz]
Foo [bar=null]

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