下面就是我的异常信息：
HTTP Status 404 - /a/

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type Status report

message /a/

description The requested resource is not available.


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Apache Tomcat/7.0.42

十月 15, 2013 2:41:44 下午 org.apache.catalina.core.AprLifecycleListener init
信息: Loaded APR based Apache Tomcat Native library 1.1.27 using APR version 1.4.6.
十月 15, 2013 2:41:44 下午 org.apache.catalina.core.AprLifecycleListener init
信息: APR capabilities: IPv6 [true], sendfile [true], accept filters [false], random [true].
十月 15, 2013 2:41:45 下午 org.apache.catalina.core.AprLifecycleListener initializeSSL
信息: OpenSSL successfully initialized (OpenSSL 1.0.1d 5 Feb 2013)
十月 15, 2013 2:41:46 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["http-apr-8080"]
十月 15, 2013 2:41:46 下午 org.apache.coyote.AbstractProtocol init
信息: Initializing ProtocolHandler ["ajp-apr-8009"]
十月 15, 2013 2:41:46 下午 org.apache.catalina.startup.Catalina load
信息: Initialization processed in 2718 ms
十月 15, 2013 2:41:46 下午 org.apache.catalina.core.StandardService startInternal
信息: Starting service Catalina
十月 15, 2013 2:41:46 下午 org.apache.catalina.core.StandardEngine startInternal
信息: Starting Servlet Engine: Apache Tomcat/7.0.42
十月 15, 2013 2:41:46 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["http-apr-8080"]
十月 15, 2013 2:41:46 下午 org.apache.coyote.AbstractProtocol start
信息: Starting ProtocolHandler ["ajp-apr-8009"]
十月 15, 2013 2:41:46 下午 org.apache.catalina.startup.Catalina start
信息: Server startup in 858 ms
十月 15, 2013 2:42:06 下午 org.apache.catalina.startup.HostConfig deployDescriptor
信息: Deploying configuration descriptor D:\eclipse\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp2\conf\Catalina\localhost\d.xml
十月 15, 2013 2:42:06 下午 org.apache.catalina.startup.SetContextPropertiesRule begin
警告: [SetContextPropertiesRule]{Context} Setting property 'source' to 'org.eclipse.jst.jee.server:d' did not find a matching property.
十月 15, 2013 2:42:56 下午 org.apache.catalina.startup.HostConfig deployDescriptor
信息: Deploying configuration descriptor D:\eclipse\workspace\.metadata\.plugins\org.eclipse.wst.server.core\tmp2\conf\Catalina\localhost\a.xml
十月 15, 2013 2:42:57 下午 org.apache.catalina.startup.SetContextPropertiesRule begin
警告: [SetContextPropertiesRule]{Context} Setting property 'source' to 'org.eclipse.jst.jee.server:a' did not find a matching property.
十月 15, 2013 2:42:57 下午 org.apache.catalina.core.StandardContext filterStart
严重: Exception starting filter CharactorFilter
java.lang.ClassNotFoundException: a.CharactorFilter
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:527)
at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:509)
at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:137)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:107)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4775)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5452)
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:656)
at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1635)
at java.util.concurrent.Executors$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:722)

十月 15, 2013 2:42:57 下午 org.apache.catalina.core.StandardContext startInternal
严重: Error filterStart
十月 15, 2013 2:42:57 下午 org.apache.catalina.core.StandardContext startInternal
严重: Context [/a] startup failed due to previous errors