title: java.lang.NoClassDefFoundError: org/zkoss/util/resource/XMLResourcesLocator Issue
body: <p>I have created a web application with Maven and ZK in IntelliJ. I have the following error that is giving me massive headaches. It says that I can't find the XMLResourceLocator class, which is in org.zkoss.common. I do have the artifact of this package in my POM file, but the problem is still there. Can someone please tell me where the problem may be?</p>
  
  <pre><code>SEVERE: Exception thrown by attributes event listener
  java.lang.NoClassDefFoundError: org/zkoss/util/resource/XMLResourcesLocator
  at org.zkoss.zk.ui.http.HttpSessionListener23.attributeAdded(HttpSessionListener23.java:87)
  at org.apache.catalina.core.ApplicationContext.setAttribute(ApplicationContext.java:859)
  at org.apache.catalina.core.ApplicationContextFacade.setAttribute(ApplicationContextFacade.java:400)
  at org.springframework.web.context.support.WebApplicationContextUtils.registerWebApplicationScopes(WebApplicationContextUtils.java:153)
  at org.springframework.web.context.support.AbstractRefreshableWebApplicationContext.postProcessBeanFactory(AbstractRefreshableWebApplicationContext.java:143)
  at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:448)
  at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:282)
  at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:204)
  at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
  at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
  at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)
  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:633)
  at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657)
  at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1637)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
  at java.lang.Thread.run(Thread.java:679)
  Caused by: java.lang.ClassNotFoundException: org.zkoss.util.resource.XMLResourcesLocator
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
  ... 23 more
  Apr 22, 2013 12:38:31 PM org.apache.catalina.core.ApplicationContext log
  SEVERE: Exception thrown by attributes event listener
  java.lang.NoClassDefFoundError: org/zkoss/util/resource/XMLResourcesLocator
  at org.zkoss.zk.ui.http.HttpSessionListener23.attributeAdded(HttpSessionListener23.java:87)
  at org.apache.catalina.core.ApplicationContext.setAttribute(ApplicationContext.java:859)
  at org.apache.catalina.core.ApplicationContextFacade.setAttribute(ApplicationContextFacade.java:400)
  at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:205)
  at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:47)
  at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
  at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)
  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:633)
  at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657)
  at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1637)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
  at java.lang.Thread.run(Thread.java:679)
  Caused by: java.lang.ClassNotFoundException: org.zkoss.util.resource.XMLResourcesLocator
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
  ... 19 more
   Apr 22, 2013 12:38:31 PM org.apache.catalina.core.StandardContext listenerStart
  SEVERE: Exception sending context initialized event to listener instance of class org.zkoss.zk.ui.http.HttpSessionListener
  java.lang.NoClassDefFoundError: org/zkoss/util/resource/XMLResourcesLocator
  at org.zkoss.zk.ui.http.HttpSessionListener23.contextInitialized(HttpSessionListener23.java:139)
  at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4791)
  at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5285)
  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:633)
  at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657)
  at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1637)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
  at java.lang.Thread.run(Thread.java:679)
  Caused by: java.lang.ClassNotFoundException: org.zkoss.util.resource.XMLResourcesLocator
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
  ... 15 more
  Apr 22, 2013 12:38:31 PM org.apache.catalina.core.ApplicationContext log
  INFO: Closing Spring root WebApplicationContext
  Apr 22, 2013 12:38:31 PM org.apache.catalina.core.ApplicationContext log
  SEVERE: Exception thrown by attributes event listener
  java.lang.NoClassDefFoundError: org/zkoss/util/resource/XMLResourcesLocator
  at org.zkoss.zk.ui.http.HttpSessionListener23.attributeRemoved(HttpSessionListener23.java:96)
  at org.apache.catalina.core.ApplicationContext.removeAttribute(ApplicationContext.java:782)
  at org.apache.catalina.core.ApplicationContextFacade.removeAttribute(ApplicationContextFacade.java:410)
  at org.springframework.web.context.ContextLoader.closeWebApplicationContext(ContextLoader.java:395)
  at org.springframework.web.context.ContextLoaderListener.contextDestroyed(ContextLoaderListener.java:78)
  at org.apache.catalina.core.StandardContext.listenerStop(StandardContext.java:4831)
  at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5478)
  at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:232)
  at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:160)
  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:633)
  at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:657)
  at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1637)
  at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
  at java.util.concurrent.FutureTask.run(FutureTask.java:166)
  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
  at java.lang.Thread.run(Thread.java:679)
  Caused by: java.lang.ClassNotFoundException: org.zkoss.util.resource.XMLResourcesLocator
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
  at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
  ... 20 more
  </code></pre>