web.xml代碼：<?xml?version="1.0"?encoding="UTF-8"?> <web-app?xmlns="http://xmlns.jcp.org/xml/ns/javaee" ?????????xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ?????????xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee?http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" ?????????version="4.0"?metadata-complete="true"> ????<servlet> ????????<servlet-name>registerServlet</servlet-name> ????????<servlet-class>servlet.HelloServlet</servlet-class> ????</servlet> ????<servlet-mapping> ????????<servlet-name>registerServlet</servlet-name> ????????<url-pattern>/servlet/HelloServlet</url-pattern> ????</servlet-mapping> ????<welcome-file-list> ????????<welcome-file>index.jsp</welcome-file> ????</welcome-file-list> </web-app>項目路徑：