如何在Spring Java配置中创建Jcache？

我在使用spring cache abstraction设置jcache时遇到问题.

@Configuration
@EnableCaching
public class CacheConfig {

    @Bean(name = "caffeineCachingProvider")
    public CachingProvider caffeineCachingProvider() {
        return new caffeineCachingProvider();
    }

    @Bean(name = "caffeineCacheManager")
    public jcacheCacheManager getSpringCacheManager() {
        CacheManager cacheManager = caffeineCachingProvider().getCacheManager();
        caffeineConfigurationcaffeineConfiguration = new caffeineConfiguration<>();
        caffeineConfiguration.setExpiryPolicyFactory(FactoryBuilder.factoryOf(new AccessedExpiryPolicy(new Duration(TimeUnit.MINUTES,60))));
        CachecaffeineConfiguration);

        jcacheCacheManager jcacheCacheManager = new jcacheCacheManager(cacheManager);
        return jcacheCacheManager;
    }

} 

我使用Caffein作为jcache.我只是无法理解我做错了什么.你能解释一下如何正确地做到这一点吗？

我得到的是NPE at line cacheManager.createCache(…)

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'caffeineCacheManager' defined in com.myapp.spring.config.CacheConfig: Bean instantiation via factory method Failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cache.jcache.jcacheCacheManager]: Factory method 'getSpringCacheManager' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
    at org.springframework.beans.factory.support.AbstractAutowireCapablebeanfactory.instantiateUsingFactoryMethod(AbstractAutowireCapablebeanfactory.java:1123)
    at org.springframework.beans.factory.support.AbstractAutowireCapablebeanfactory.createBeanInstance(AbstractAutowireCapablebeanfactory.java:1018)
    at org.springframework.beans.factory.support.AbstractAutowireCapablebeanfactory.doCreateBean(AbstractAutowireCapablebeanfactory.java:510)
    at org.springframework.beans.factory.support.AbstractAutowireCapablebeanfactory.createBean(AbstractAutowireCapablebeanfactory.java:482)
    at org.springframework.beans.factory.support.Abstractbeanfactory$1.getobject(Abstractbeanfactory.java:306)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
    at org.springframework.beans.factory.support.Abstractbeanfactory.doGetBean(Abstractbeanfactory.java:302)
    at org.springframework.beans.factory.support.Abstractbeanfactory.getBean(Abstractbeanfactory.java:197)
    at org.springframework.beans.factory.support.DefaultListablebeanfactory.preInstantiateSingletons(DefaultListablebeanfactory.java:772)
    at org.springframework.context.support.AbstractApplicationContext.finishbeanfactoryInitialization(AbstractApplicationContext.java:839)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538)
    at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:668)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:634)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:682)
    at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:553)
    at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:494)
    at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:136)
    at javax.servlet.GenericServlet.init(GenericServlet.java:158)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284)
    at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5266)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5554)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:652)
    at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:677)
    at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1912)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.cache.jcache.jcacheCacheManager]: Factory method 'getSpringCacheManager' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
    ... 34 more
Caused by: java.lang.NullPointerException
    at com.github.benmanes.caffeine.jcache.CacheProxy.nes.caffeine.jcache.CacheFactory$Builder.newCacheProxy(CacheFactory.java:160)
    at com.github.benmanes.caffeine.jcache.CacheFactory$Builder.build(CacheFactory.java:145)
    at com.github.benmanes.caffeine.jcache.CacheFactory.createCache(CacheFactory.java:82)
    at com.github.benmanes.caffeine.jcache.CacheManagerImpl.lambda$createCache$0(CacheManagerImpl.java:98)
    at com.github.benmanes.caffeine.jcache.CacheManagerImpl$$Lambda$23/388708304.apply(UnkNown Source)
    at java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1853)
    at com.github.benmanes.caffeine.jcache.CacheManagerImpl.createCache(CacheManagerImpl.java:94)
    at com.myapp.spring.config.CacheConfig.getSpringCacheManager(CacheConfig.java:55)
    at com.myapp.spring.config.CacheConfig$$EnhancerBySpringcglib$$4f46e611.cglib$getSpringCacheManager$1(fig.CacheConfig$$EnhancerBySpringcglib$$4f46e611$$FastClassBySpringcglib$$b70e5f67.invoke(cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:355)
    at com.myapp.spring.config.CacheConfig$$EnhancerBySpringcglib$$4f46e611.getSpringCacheManager(java.lang.reflect.Method.invoke(Method.java:497)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
    ... 35 more

最佳答案

了解有关咖啡因配置的更多信息.其jcache适配器使用默认规范(jcache)设置,该设置指出条目永不过期并按值存储(从缓存中放入/检索时复制). (reference here).

当缓存设置为复制实例时,您应该选择足够的复制器来处理它.所以你可以写：

caffeineConfiguration.setcopierFactory(JavaSerializationcopier::new);

要么

caffeineConfiguration.setcopierFactory(copier::identity);

这取决于您是否希望在缓存键/值突变的情况下是安全的.

尽管如此,建议的选项是使用default settings禁用store-by-value选项并且需要复印机：

Config config = ConfigFactory.load();
caffeineConfigurationcaffeineConfiguration = TypesafeConfigurator.defaults(config);
caffeineConfiguration.setExpiryPolicyFactory(factoryOf(new AccessedExpiryPolicy(new Duration(
            TimeUnit.MINUTES,60))));

或者,您可以通过以下方式禁用按值设置：

caffeineConfiguration.setStoreByValue(false);