今天用myEclipse写servlet的时候,报了下面的错。百度的方法说jar包冲突,或者改pom.xml文件,OMG,我连文件都没有找到好吗。。。
严重: Allocate exception for servlet [UserUpdate_servlet]
java.lang.ClassCastException: User.UserUpdate_servlet cannot be cast to javax.servlet.Servlet
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1042)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:761)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:135)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:688)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
后来发现是servlet
没有继承父类HttpServlet
的问题。。。要加上方框里面的语句。