写Servlet时为了方便，我就复制 了一个Servlet，只改了逻辑但是运行时就出现了如下
Tomcat无法启动的情况：
严重: A child container failed during start
java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException:
Failed to start component
[StandardEngine[Catalina].StandardHost[localhost].StandardContext[/mysql_crud]]
at java.util.concurrent.FutureTask.report(Unknown Source) at java.util.concurrent.FutureTask.get(Unknown Source) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1119) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:819) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1571) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1561) 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) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/mysql_crud]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162) ... 6 more Caused by: java.lang.IllegalArgumentException: The servlets named [cn.iponkan.service.AddServlet] and [cn.iponkan.service.UpdateServlet] are both mapped to the url-pattern [/UpdateServlet] which is not permittedat org.apache.catalina.deploy.WebXml.addServletMapping(WebXml.java:293)
原因是：我这个地方没改，更改为当前Servlet名称后问题成功解决。
