我得到的org.apache.catalina。LifecycleException:在使用tomcat7配置动态web项目时，未能启动组件错误

This is my web.xml

这是我的web . xml

    <?xml version="1.0" encoding="UTF-8"?>

    <web-app xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance" 
    xmlns="https://java.sun.com/xml/ns/javaee" 
    xsi:schemaLocation="https://java.sun.com/xml/ns/javaee https://java.sun.com/xml/ns/javaee/web-
    app_3_0.xsd" id="WebApp_ID" version="3.0">

     <display-name>VideoPlayer</display-name>

     <welcome-file-list>

        <welcome-file>index.html</welcome-file>

        <welcome-file>index.htm</welcome-file>

        <welcome-file>index.jsp</welcome-file>

        <welcome-file>default.html</welcome-file>

        <welcome-file>default.htm</welcome-file>

        <welcome-file>default.jsp</welcome-file>

      </welcome-file-list>

      <servlet>
    <servlet-name>UploadServlet</servlet-name>
    <servlet-class>com.videoplayer.controller.UploadServlet</servlet-class>

     </servlet>

    <servlet-mapping>
    <servlet-name>UploadServlet</servlet-name>
    <url-pattern>/UploadServlet</url-pattern>

    </servlet-mapping>

    </web-app>
    <?xml