Java 21升级后Spring Boot 3的SQS监听器无法解析自定义对象消息

我正在将一个基于微服务的系统从Java 17升级到Java 21，运行在Spring Boot 3和Spring Framework 6上。我的应用程序将自定义对象（Event）发送到AWS SQS队列，但我的消息监听器期望接收String类型。这在Java 17中运行正常，但升级后，监听器因为JSON解析问题无法处理消息。

问题 #

当使用 sqsTemplate.send(queueName, myEvent) 发送Event对象时，监听器抛出以下异常：

Caused by: com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'no': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
 at [Source: REDACTED (`StreamReadFeature.INCLUDE_SOURCE_IN_LOCATION` disabled); line: 1, column: 3]
    at com.fasterxml.jackson.core.JsonParser._constructError(JsonParser.java:2572)
    at com.fasterxml.jackson.core.JsonParser._constructReadException(JsonParser.java:2598)
    at com.fasterxml.jackson.core.JsonParser._constructReadException(JsonParser.java:2606)
    at com.fasterxml.jackson.core.base.ParserMinimalBase._reportError(ParserMinimalBase.java:765)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._reportInvalidToken(ReaderBasedJsonParser.java:3018)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._reportInvalidToken(ReaderBasedJsonParser.java:2996)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._matchToken(ReaderBasedJsonParser.java:2761)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser._matchNull(ReaderBasedJsonParser.java:2747)
    at com.fasterxml.jackson.core.json.ReaderBasedJsonParser.nextToken(ReaderBasedJsonParser.java:750)
    at com.fasterxml.jackson.databind.ObjectMapper._initForReading(ObjectMapper.java:4992)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4898)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3848)
    at org.springframework.messaging.converter.MappingJackson2MessageConverter.convertFromInternal(MappingJackson2MessageConverter.java:251)
    ... 27 common frames omitted

调试后发现，MappingJackson2MessageConverter 内部的 payload.toString() 返回的是对象引用而非JSON字符串：

no.com.common.Event@6f8e5dfd

配置详情 #

SQS监听器与消息转换 #

监听器代码：

@SqsListener(value = "${sqs.queue.event.in}", acknowledgementMode = SqsListenerAcknowledgementMode.MANUAL)
public void receiveHourEvent(Acknowledgement acknowledgement, String event){
    LOG.info("SQSListener triggered");
}

容器工厂与模板配置：

@Bean
SqsMessageListenerContainerFactory<Object> defaultSqsListenerContainerFactory(SqsAsyncClient sqsAsyncClient,
                                                                              SqsMessagingMessageConverter sqsMessagingMessageConverter,
                                                                              SqsReceiverErrorHandler sqsReceiverErrorHandler,
                                                                              @Value("${sqs.poll.timeout}") Duration pollTimeout,
                                                                              @Value("${sqs.poll.messagevisibility}") Duration pollMessageVisibility) {
    return SqsMessageListenerContainerFactory
            .builder()
            .configure(options -> options
                    .maxMessagesPerPoll(10)
                    .pollTimeout(pollTimeout)
                    .messageVisibility(pollMessageVisibility)
                    .messageConverter(sqsMessagingMessageConverter))
            .sqsAsyncClient(sqsAsyncClient)
            .messageInterceptor(new BreadcrumbMessageInterceptor())
            .errorHandler(sqsReceiverErrorHandler)
            .build();
}

@Bean
SqsTemplate sqsTemplate(SqsAsyncClient sqsAsyncClient, SqsMessagingMessageConverter sqsMessagingMessageConverter) {
    SqsTemplate sqsTemplate = SqsTemplate.builder()
            .sqsAsyncClient(sqsAsyncClient)
            .messageConverter(sqsMessagingMessageConverter)
            .build();
    return sqsTemplate;
}

@Bean
public SqsMessagingMessageConverter sqsMessagingMessageConverter(SqsExtendedClient sqsExtendedClient) {
    ExtendedSqsMessagingMessageConverter converter = new ExtendedSqsMessagingMessageConverter(sqsExtendedClient);
    converter.setObjectMapper(JsonMappers.getObjectMapper());
    return converter;
}

ObjectMapper配置：

private static ObjectMapper initializeMapper() {
        final ObjectMapper mapper = new ObjectMapper();
        mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY)
                .setVisibility(PropertyAccessor.GETTER, JsonAutoDetect.Visibility.NONE)
                .setVisibility(PropertyAccessor.IS_GETTER, JsonAutoDetect.Visibility.NONE);

        mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
        mapper.registerModule(new JavaTimeModule());
        mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
        mapper.configure(DeserializationFeature.READ_UNKNOWN_ENUM_VALUES_AS_NULL, true);
        mapper.disable(SerializationFeature.WRITE_DATE_KEYS_AS_TIMESTAMPS);
        mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);

        return mapper;
}

public static <T> T fromJson(String text, Class<T> type) {
    try {
        return getObjectMapper().readValue(text, type);
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

public static <T> String toJson(T value) {
    try {
        return getObjectMapper().writeValueAsString(value);
     } catch (IOException e) {
        throw new RuntimeException(e);
     }
}

Event对象 #

public class Event {
    String eventName;
    Instant dateTime;
}

发送消息的代码：

sqsTemplate.send(queueName, myEvent);

我已经验证手动调用 toJson(myEvent) 可以正确序列化对象，也确认了 sqsMessagingMessageConverter 已正确设置到 SqsTemplate 中。调试时看到 MappingJackson2MessageConverter 里的这行代码返回的是对象引用：

return this.objectMapper.readValue(payload.toString(), javaType)

依赖版本 #

<!--JSON serialization-->
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jsr310</artifactId>
    <version>2.17.2</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.17.2</version>
</dependency>

疑问 #

为什么 payload 被当作对象引用而不是JSON字符串处理？是我的ObjectMapper配置有遗漏，还是需要调整SqsMessagingMessageConverter的序列化处理方式？

备注：内容来源于stack exchange，提问作者Zoe