java.lang.ClassNotFoundException: net.spy.memcached.compat.log.SLF4JLogger

Question

dodałem Java zdecyduje -Dnet.spy.log.LoggerImpl = net.spy.memcached.compat.log.SLF4JLogger do powołanego do spymemcached użyj slf4j jako logger. Ale jestem coraz następujące ostrzeżenie w dziennikach tomcat6 i jestem zaskoczony nad błędem

net.spy.memcached.compat.log.SLF4JLogger not found while initializing net.spy.compat.log.LoggerFactory java.lang.ClassNotFoundException: net.spy.memcached.compat.log.SLF4JLogger 

Jak to może być możliwe, że SLF4JLogger klasa nie została znaleziona. To, że inicjowało LoggerFactory, oznacza, że ​​pakiet net.spy był dostępny i ogólnie rzecz biorąc, był dostępny pojemnik memcache szpiegującego. Jak więc może nie znaleźć drugiej klasy.

log4j: setFile ended log4j: Adding appender named [SecurityAuditAppender] to category [SecurityAuditLogger]. Warning: net.spy.memcached.compat.log.SLF4JLogger not found while initializing net.spy.compat.log.LoggerFactory java.lang.ClassNotFoundException: net.spy.memcached.compat.log.SLF4JLogger 
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680) 
     at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526) 
     at java.lang.Class.forName0(Native Method) 
     at java.lang.Class.forName(Class.java:191) 
     at net.spy.memcached.compat.log.LoggerFactory.getConstructor(LoggerFactory.java:131) 
     at net.spy.memcached.compat.log.LoggerFactory.getNewInstance(LoggerFactory.java:115) 
     at net.spy.memcached.compat.log.LoggerFactory.internalGetLogger(LoggerFactory.java:98) 
     at net.spy.memcached.compat.log.LoggerFactory.getLogger(LoggerFactory.java:87) 
     at net.spy.memcached.compat.log.LoggerFactory.getLogger(LoggerFactory.java:73) 
     at net.spy.memcached.compat.SpyThread.getLogger(SpyThread.java:60) 
     at net.spy.memcached.MemcachedConnection.createConnections(MemcachedConnection.java:152) 
     at net.spy.memcached.MemcachedConnection.<init>(MemcachedConnection.java:128) 
     at net.spy.memcached.DefaultConnectionFactory.createConnection(DefaultConnectionFactory.java:176) 
     at net.spy.memcached.MemcachedClient.<init>(MemcachedClient.java:193) 
     at net.spy.memcached.spring.MemcachedClientFactoryBean.getObject(MemcachedClientFactoryBean.java:72) 
     at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.doGetObjectFromFactoryBean(FactoryBeanRegistrySupport.java:142) 
     at org.springframework.beans.factory.support.FactoryBeanRegistrySupport.getObjectFromFactoryBean(FactoryBeanRegistrySupport.java:102) 
     at org.springframework.beans.factory.support.AbstractBeanFactory.getObjectForBeanInstance(AbstractBeanFactory.java:1442) 
     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:248) 
     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) 
     at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:322) 
     at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:106) 
     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1360) 
     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1118) 
     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517) 
     at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) 
     at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294) 
     at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225) 
     at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291) 
     at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193) 
     at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585) 
     at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913) 
     at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464) 
     at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:385) 
     at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:284) 
     at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:111) 
     at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4210) 
     at org.apache.catalina.core.StandardContext.start(StandardContext.java:4709) 
     at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799) 
     at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779) 
     at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:583) 
     at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:675) 
     at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:601) 
     at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:502) 
     at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317) 
     at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324) 
     at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142) 
     at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065) 
     at org.apache.catalina.core.StandardHost.start(StandardHost.java:822) 
     at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057) 
     at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463) 
     at org.apache.catalina.core.StandardService.start(StandardService.java:525) 
     at org.apache.catalina.core.StandardServer.start(StandardServer.java:754) 
     at org.apache.catalina.startup.Catalina.start(Catalina.java:595) 
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) 
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
     at java.lang.reflect.Method.invoke(Method.java:606) 
     at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289) 
     at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414) 

Answer 1

Jeśli WebAppClassLoader rzuca ClassNotFoundException, to klasa nie jest w aplikacji internetowej. Uzyskaj latest version słoiczka klienta spymemcached (2.12.1 w chwili pisania tego wpisu) i umieść go w katalogu swojej aplikacji internetowej w katalogu WEB-INF/lib. Usuń wszystkie inne słoiki z tego katalogu, aby uniknąć konfliktów związanych z ładowaniem klas.

net.spy.memcached.compat.log.SLF4JLogger został wprowadzony dopiero w wersji 2.9.0, więc jeśli używasz starszej wersji net.spy:spymemcached, które mogłyby wyjaśnić, dlaczego to może znaleźć LoggerFactory ale nie SLF4JLogger.

Answer 2

można sprawdzić drzewa zależności z Dependency Plugin

mvn dependency:tree -Dverbose -Dincludes=spymemcached 

jeśli widzisz żadnej innej wersji obok 2.12.1, sprawdź to top odniesienia i dodać tag wykluczeniu na to Maven elementem zależność jak:

<dependency> 
    <groupId>org.springframework</groupId> 
    <artifactId>spring-beans</artifactId> 
    <version>3.0.3.RELEASE</version> 
    <exclusions> 
     <exclusion> 
      <groupId>net.spy</groupId> 
      <artifactId>spymemcached</artifactId> 
     </exclusion> 
    </exclusions> 
</dependency