Server Tomcat v7.0 Server at localhost failed to start

使用Servlet写了一个小项目，利用Eelipse创建了一个servlet，

自带了有@WebServlet("/LYPosition")，项目运行起来没毛病。杠杠的！

但是运行几次过后，就出现了问题了，报错了，启动失败！

以为是端口问题，关闭重启了，一看界面才发现不是端口，端口被占用会有提示的！真是想当然啊！！！！啪啪啪！要给自己长长记性！

看报错信息啊！报错信息如下

严重: A child container failed during startjava.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/LYPosition]]at java.util.concurrent.FutureTask.report(FutureTask.java:122)at java.util.concurrent.FutureTask.get(FutureTask.java:192)at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1122)at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:819)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1574)at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1564)at java.util.concurrent.FutureTask.run(FutureTask.java:266)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)at java.lang.Thread.run(Thread.java:745)Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/LYPosition]]at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)... 6 moreCaused by: java.lang.IllegalArgumentException: The servlets named [LYPosition] and [cn.newer.action.LYPosition] are both mapped to the url-pattern [/LYPosition] which is not permittedat org.apache.catalina.deploy.WebXml.addServletMapping(WebXml.java:293)at org.apache.catalina.startup.ContextConfig.processAnnotationWebServlet(ContextConfig.java:2443)at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:2118)at org.apache.catalina.startup.ContextConfig.processAnnotationsFile(ContextConfig.java:2079)at org.apache.catalina.startup.ContextConfig.processAnnotationsFile(ContextConfig.java:2072)at org.apache.catalina.startup.ContextConfig.processAnnotationsFile(ContextConfig.java:2072)at org.apache.catalina.startup.ContextConfig.processAnnotationsFile(ContextConfig.java:2072)at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1304)at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5479)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)... 6 more九月 08, 2017 3:22:43 下午 org.apache.catalina.core.ContainerBase startInternal严重: A child container failed during startjava.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]at java.util.concurrent.FutureTask.report(FutureTask.java:122)at java.util.concurrent.FutureTask.get(FutureTask.java:192)at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1122)at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)at org.apache.catalina.startup.Catalina.start(Catalina.java:693)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:497)at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:428)Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1574)at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1564)at java.util.concurrent.FutureTask.run(FutureTask.java:266)at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)at java.lang.Thread.run(Thread.java:745)Caused by: org.apache.catalina.LifecycleException: A child container failed during startat org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1130)at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:819)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)... 6 more九月 08, 2017 3:22:43 下午 org.apache.catalina.startup.Catalina start严重: The required Server component failed to start so Tomcat is unable to start.org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)at org.apache.catalina.startup.Catalina.start(Catalina.java:693)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)at java.lang.reflect.Method.invoke(Method.java:497)at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:428)Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)... 7 moreCaused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)... 9 moreCaused by: org.apache.catalina.LifecycleException: A child container failed during startat org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1130)at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)... 11 more

最关键的来了：

The servlets named [LYPosition] and [cn.newer.action.LYPosition] are both mapped to the url-pattern [/LYPosition] which is not permitted

翻译的意思是：

名为[ lyposition ]和[ cn.newer.action.lyposition ]的servlet都映射到不允许的URL模式[ / lyposition ]

也就是说web.xml中配置的<url-pattern>和servlet注解中的冲突了。解决其中一个就行啦。

恩，又学到一手！不积跬步无以至千里！

好好学，好好练！