Mono返回值的缓存注释没有合适的Hazelcast序列化程序

Question

使用spring-boot和spring-webflux并与hazelcast集成时，尝试使用基于注释的缓存时会出现错误。

我试着只使用spring-cache而不使用hazelcast，效果很好。但我应该使用hazelcast。

Maven依赖项

  <dependency>
        <groupId>com.hazelcast</groupId>
        <artifactId>hazelcast</artifactId>
    </dependency>
    <dependency>
        <groupId>com.hazelcast</groupId>
        <artifactId>hazelcast-spring</artifactId>
    </dependency>

在使用可缓存批注时的普通方法中

@Cacheable("ref-id")
public Mono<String> testCache(String testValue) {
    try {
        TimeUnit.SECONDS.sleep(5);  // (1)
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
        return Mono.just(testValue);
}

抛出此错误

com.hazelcast.nio.serialization.HazelcastSerializationException: Failed to serialize 'reactor.core.publisher.MonoJust'
at com.hazelcast.internal.serialization.impl.SerializationUtil.handleSerializeException(SerializationUtil.java:75)
at com.hazelcast.internal.serialization.impl.AbstractSerializationService.toBytes(AbstractSerializationService.java:157)
at com.hazelcast.internal.serialization.impl.AbstractSerializationService.toBytes(AbstractSerializationService.java:133)
at com.hazelcast.internal.serialization.impl.AbstractSerializationService.toData(AbstractSerializationService.java:118)
at com.hazelcast.internal.serialization.impl.AbstractSerializationService.toData(AbstractSerializationService.java:106) 
.
.
Caused by: com.hazelcast.nio.serialization.HazelcastSerializationException: There is no suitable serializer for class reactor.core.publisher.MonoJust
at com.hazelcast.internal.serialization.impl.AbstractSerializationService.serializerFor(AbstractSerializationService.java:487)
at com.hazelcast.internal.serialization.impl.AbstractSerializationService.toBytes(AbstractSerializationService.java:146)

Answer 1

尝试在Reactor附加组件中使用CacheMono。

这里的例外是因为Hazelcast找不到序列化Mono<T>的方法。您放在Hazelcast缓存中的所有内容都必须具有某种序列化机制，因为缓存存储可能位于远程JVM上。Mono本身并不提供一种机制。

Mono<T>对你来说意味着Mono<String>，序列化字符串是内置在Hazelcast中的，所以你不需要担心它是如何完成的。