Wie erstelle ich eine Jcache in Spring Java config?

Question

Ich habe ein Problem beim Einrichten eines jcache mit spring cache abstraction.

@Configuration 
@EnableCaching 
public class CacheConfig { 

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

    @Bean(name = "caffeineCacheManager") 
    public JCacheCacheManager getSpringCacheManager() { 
     CacheManager cacheManager = caffeineCachingProvider().getCacheManager(); 
     CaffeineConfiguration<String, List<Product>> caffeineConfiguration = new CaffeineConfiguration<>(); 
     caffeineConfiguration.setExpiryPolicyFactory(FactoryBuilder.factoryOf(new AccessedExpiryPolicy(new Duration(TimeUnit.MINUTES, 60)))); 
     Cache<String, List<Product>> productCache = cacheManager.createCache("productCache", caffeineConfiguration); 

     JCacheCacheManager jCacheCacheManager = new JCacheCacheManager(cacheManager); 
     return jCacheCacheManager; 
    } 

} 

Ich benutze Caffein als Jcache. Ich kann einfach nicht verstehen, was ich falsch mache. Würdest du erklären, wie es richtig gemacht wird?

Was ich erhalte ist NPE in Zeile 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.<init>(CacheProxy.java:109) 
    at com.github.benmanes.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$$4f46e611.CGLIB$getSpringCacheManager$1(<generated>) 
    at com.myapp.spring.config.CacheConfig$$EnhancerBySpringCGLIB$$4f46e611$$FastClassBySpringCGLIB$$b70e5f67.invoke(<generated>) 
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) 
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:355) 
    at com.myapp.spring.config.CacheConfig$$EnhancerBySpringCGLIB$$4f46e611.getSpringCacheManager(<generated>) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:497) 
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) 
    ... 35 more 

Answer 1

mehr über Caffeine Konfiguration lesen. Sein JCache Adapter verwendet Standardspezifikation (JCache) Einstellungen, die besagt, dass Einträge nie ablaufen und nach Wert gespeichert werden (kopiert, wenn put/aus dem Cache abgerufen). (reference here).

Wenn der Cache auf das Kopieren von Instanzen eingestellt ist, sollten Sie eine geeignete Copier auswählen, die das übernimmt. So können Sie einfach schreiben:

caffeineConfiguration.setCopierFactory(JavaSerializationCopier::new); 

oder

caffeineConfiguration.setCopierFactory(Copier::identity); 

Es hängt davon ab, ob Sie im Falle eines Cache-Schlüssel/Wert-Mutationen, sicher sein möchten.

Dennoch die empfohlene Option istdefault settings zu verwenden, wo store-by-value Option deaktiviert ist und Kopierer ist notwendig:

Config config = ConfigFactory.load(); 
CaffeineConfiguration<String, List<Product>> caffeineConfiguration = TypesafeConfigurator.defaults(config); 
caffeineConfiguration.setExpiryPolicyFactory(factoryOf(new AccessedExpiryPolicy(new Duration(
      TimeUnit.MINUTES, 60)))); 

Alternativ können Sie nur store-by-value Einstellung deaktivieren:

caffeineConfiguration.setStoreByValue(false);