java web程序中web.xml文件中servlet-name、url-pattern的值不能与映射的类名一致，否则tomcat启动不了，报错误： Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/Servlet_day02]]

     新建一个web程序Servlet_day02新建一个ServletDemo1类继承HttpServlet，然后配置web.xml：

启动tomcat，一直报错：

  

报的错误是：Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/Servlet_day02]]，

Caused by: java.lang.IllegalArgumentException: The servlets named [ServletDemo1] and [com.guan.servlet.ServletDemo1] are both mapped to the url-pattern [/ServletDemo1] which is not permitted

说明：servlet-name与url-pattern不能都与映射的类文件名相同。修改之：

启动tomcat，成功。