JCache：指定的缓存键类型不兼容

Question

我在 Spring Boot 中配置缓存时遇到问题。它工作正常，经过一些无关的更改后，它停止工作。

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;

}

我按以下方式使用缓存：

@CacheResult(cacheName = "userMappingCache")

public String getPayrollUserName(@CacheKey String userName, String description) {...}

但是，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]

    ....

我搜索了一下，发现了一些条目，这些条目主要与键/值的序列化类似的问题有关。即使是原始类也是这个原因吗？我该如何解决？提前致谢。

Answer 1

从我的评论来看，似乎答案MutableConfiguration是没有使用setType(Class<K>,Class<V>)这将配置缓存的键和值类型。如果没有，它会默认为Object，这是与（隐含的）类型的不兼容String的@CacheKey/@CacheResult配对听写。