Fórum Tutorial Spring social java edição 99 #426346

Estou com o seguinte problema quando subo a aplicação:

GRAVE: Error configuring application listener of class org.springframework.web.context.ContextLoaderListener
java.lang.ClassNotFoundException: org.springframework.web.context.ContextLoaderListener
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1688)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1533)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:525)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:507)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:124)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4701)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5260)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1525)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1515)
at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
16/10/2012 17:24:41 org.apache.catalina.core.StandardContext listenerStart
GRAVE: Skipped installing application listeners due to previous error(s)
16/10/2012 17:24:41 org.apache.catalina.core.StandardContext startInternal
GRAVE: Error listenerStart
16/10/2012 17:24:41 org.apache.catalina.core.StandardContext startInternal
GRAVE: Context [/exemplo-spring-social] startup failed due to previous errors

Alguem pode me ajudar?