出现这样的错误是怎么回事呢,求解答
七月 08, 2016 11:25:18 下午 org.apache.catalina.core.AprLifecycleListener init
信息: Loaded APR based Apache Tomcat Native library 1.1.29 using APR version 1.4.8.
七月 08, 2016 11:25:18 下午 org.apache.catalina.core.AprLifecycleListener init
信息: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
七月 08, 2016 11:25:18 下午 org.apache.tomcat.util.digester.SetPropertiesRule begin
警告: [SetPropertiesRule]{Server/Service/Engine/Host/Context} Setting property 'source' to 'org.eclipse.jst.jee.server:HelloWorld' did not find a matching property.
七月 08, 2016 11:25:19 下午 org.apache.catalina.core.AprLifecycleListener initializeSSL
信息: OpenSSL successfully initialized (OpenSSL 1.0.1e 11 Feb 2013)
七月 08, 2016 11:25:19 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["http-apr-8088"]
七月 08, 2016 11:25:19 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["ajp-apr-8009"]
七月 08, 2016 11:25:19 下午 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 1832 ms
七月 08, 2016 11:25:19 下午 org.apache.catalina.core.StandardService startInternal
信息: Starting service Catalina
七月 08, 2016 11:25:19 下午 org.apache.catalina.core.StandardEngine startInternal
信息: Starting Servlet Engine: Apache Tomcat/7.0.52
七月 08, 2016 11:25:21 下午 org.apache.catalina.util.SessionIdGenerator createSecureRandom
信息: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [168] milliseconds.
七月 08, 2016 11:25:22 下午 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter struts2
java.lang.ClassNotFoundException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1718)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:529)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:511)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:139)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:258)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4809)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5485)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559)
at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549)
at java.util.concurrent.FutureTask.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
七月 08, 2016 11:25:22 下午 org.apache.catalina.core.StandardContext startInternal
严重: Error filterStart
七月 08, 2016 11:25:22 下午 org.apache.catalina.core.StandardContext startInternal
严重: Context [/HelloWorld] startup failed due to previous errors
七月 08, 2016 11:25:22 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-apr-8088"]
七月 08, 2016 11:25:22 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["ajp-apr-8009"]
七月 08, 2016 11:25:22 下午 org.apache.catalina.startup.Catalina start
信息: Server startup in 2807 ms