Exception starting filter simple

严重: Exception starting filter simple
java.lang.ClassNotFoundException: org.lxh.filterdemo.SimpleFilter
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1680)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:269)
at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:424)
at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4076)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4730)
at org.apache.catalina.startup.HostConfig.checkResources(HostConfig.java:1284)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1382)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:306)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1389)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1653)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1662)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1642)
at java.lang.Thread.run(Thread.java:619)