eclipse 中新建的Dynamic Web Project 3.0之后无web.xml中Servlet的配置问题

一时失言乱红尘 2021-09-22 16:20 521阅读 0赞

在eclipse 中新建Dynamic Web Project时如果之间点击finish，项目中会没有web.xml，但是不会影响本地的项目运行，如果需要web.xml则需要在新建时点击next，最后勾选生成web.xml。  
![在这里插入图片描述][20161104194737334]  
那么没有web.xml，servlet的对应关系在哪呢？我今天就遇到了这样的问题，将本地的项目部署到服务器上时，报找不到servlet的错误，所以需要考一个web.xml到WEB-INF下，并且在下面添加servlet的映射关系：

<servlet>
 <servlet-name>Sevlet1</servlet-name>
 <servlet-class>com.Sevlet.InfoSevlet</servlet-class>
 </servlet>
 <servlet-mapping>
 <servlet-name>Sevlet1</servlet-name>
 <url-pattern>/InfoSevlet</url-pattern>
 </servlet-mapping>

上面是一个servlet的配置：红色的地方是可以随便起的一个名字，但是标签中的和中的要一致，蓝色部分是servlet所在的包名（包名.servlet）.但是重启tomcat之后报如下错误：

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/InfoManager]]
 	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
 	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:725)
 	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
 	at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
 	at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:586)
 	at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1750)
 	at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
 	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: java.lang.IllegalArgumentException: The servlets named [Sevlet1] and [com.Sevlet.InfoSevlet] are both mapped to the url-pattern [/InfoSevlet] which is not permitted
 	at org.apache.tomcat.util.descriptor.web.WebXml.addServletMapping(WebXml.java:308)
 	at org.apache.catalina.startup.ContextConfig.processAnnotationWebServlet(ContextConfig.java:2342)
 	at org.apache.catalina.startup.ContextConfig.processAnnotationsStream(ContextConfig.java:2024)
 	at org.apache.catalina.startup.ContextConfig.processAnnotationsWebResource(ContextConfig.java:1918)
 	at org.apache.catalina.startup.ContextConfig.processAnnotationsWebResource(ContextConfig.java:1913)
 	at org.apache.catalina.startup.ContextConfig.processAnnotationsWebResource(ContextConfig.java:1913)
 	at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1139)
 	at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:771)
 	at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:305)
 	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:5066)
 	at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
 	... 10 more
 十一月 04, 2016 7:59:39 下午 org.apache.catalina.startup.HostConfig deployDescriptor
 严重: Error deploying configuration descriptor D:\eclipse\work.metadata.plugins\org.eclipse.wst.server.core\tmp0\conf\Catalina\localhost\InfoManager.xml
 java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/InfoManager]]
 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:729)
 at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:701)
 at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
 at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:586)
 at org.apache.catalina.startup.HostConfigDeployDescriptor.run(HostConfig.java:1750) at java.util.concurrent.ExecutorsDeployDescriptor.run(HostConfig.java:<spanclass="hljs−number">1750)atjava.util.concurrent.ExecutorsRunnableAdapter.call(Unknown Source)
 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)

网上查了好久才知道原因如下：  
![在这里插入图片描述][20161104195945647]新建servlet时它会自动加一个url-pattern声明，所以才会在没有web.xml中配置信息的情况找到对应的servlet。

这样如果你在web.xml中再加上映射关系的话就会重复。所以删除servlet里的声明即可

[20161104194737334]: /images/20210920/f1f1ba6b94044e6d8e47f86e5b971931.png
[20161104195945647]: /images/20210920/17d064d49c88454f8be6c4208d9af3e1.png