JCache：指定的缓存键类型不兼容，预期 class java.lang.Object 但 class java.lang.String

Question

我在 Spring 启动时配置缓存时遇到问题。它工作正常，但经过一些不相关的更改后，它停止工作了。

我有以下缓存配置：

@Configuration
public class UserMappingCacheConfig {
    public static final String USER_MAPPING_CACHE = "userMappingCache";

@Bean(name = "userMappingCache")
public Cache<String, String> getUserMappingCache(JCacheCacheManager cacheManager) {
    CacheManager cm = cacheManager.getCacheManager();
    Cache<String, String> cache = cm.getCache(USER_MAPPING_CACHE, String.class, String.class);
    if (cache == null)
        cache = cm.createCache(USER_MAPPING_CACHE, getUserMappingCacheConfiguration());
    return cache;
}

private MutableConfiguration<String, String> getUserMappingCacheConfiguration() {
    MutableConfiguration<String, String> configuration =
            new MutableConfiguration<String, String>()
                    .setStoreByValue(true)
                    .setExpiryPolicyFactory( FactoryBuilder.factoryOf(
                            new CreatedExpiryPolicy( Duration.ONE_DAY)
                    ));
    return configuration;
}

我使用缓存的方式如下：

@CacheResult(cacheName = "userMappingCache")
public String getPayrollUserName(@CacheKey String userName, String description) {...}

但是，当运行服务时出现以下异常：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userMappingCache' defined in class path resource [UserMappingCacheConfig.class]: 
Bean instantiation via factory method failed;
nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.cache.Cache]: Factory method 'getUserMappingCache' threw exception; 
nested exception is java.lang.ClassCastException: Incompatible cache key types specified, expected class java.lang.Object but class java.lang.String was specified
                at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
    ....
    Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.cache.Cache]: Factory method 'getUserMappingCache' threw exception; 
nested exception is java.lang.ClassCastException: Incompatible cache key types specified, expected class java.lang.Object but class java.lang.String was specified
                    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
                    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) ~[spring-beans-4.3.11.RELEASE.jar:4.3.11.RELEASE]
    ....
    Caused by: java.lang.ClassCastException: Incompatible cache key types specified, expected class java.lang.Object but class java.lang.String was specified
                    at com.hazelcast.cache.impl.AbstractHazelcastCacheManager.getCache(AbstractHazelcastCacheManager.java:200) ~[hazelcast-3.10.jar:3.10]
                    at com.hazelcast.cache.impl.AbstractHazelcastCacheManager.getCache(AbstractHazelcastCacheManager.java:67) ~[hazelcast-3.10.jar:3.10]

我四处搜索，发现一些条目大多与 keys/values 的序列化相关。这就是原始 class 的原因吗？我该如何解决？提前致谢。

Answer 1

根据我的评论，答案似乎是 MutableConfiguration 没有使用

setType(Class<K>,Class<V>)

配置缓存的键值类型。没有它，它将默认为 Object，这与 @CacheKey/@CacheResult 配对指示的 String 的（隐含）类型不兼容。

JCache：指定的缓存键类型不兼容，预期 class java.lang.Object 但 class java.lang.String

JCache: Incompatible cache key types specified, expected class java.lang.Object but class java.lang.String

java

jcache

hazelcast

spring-boot