嚴重: Allocate exception for servlet ListServlet

java.lang.ClassNotFoundException: cn.edu.ujn.servlet.ListServlet

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1892)

at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1735)

at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:504)

at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:486)

at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:113)

at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1133)

at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:853)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:134)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:442)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1083)

at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:640)

at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

at java.lang.Thread.run(Thread.java:745)