向JSP添加注释

您需要有一个servlet和一个servlet-mapping标签。

<?xml version="1.0" encoding="UTF-8"?><web-app version="3.1" 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_3_1.xsd"><session-config>    <session-timeout>        30    </session-timeout></session-config><servlet>   <servlet-name>uploadfile</servlet-name><jsp-file>/mainPage.jsp</jsp-file><multipart-config>    <location>/temp</location>    <max-file-size>20848820</max-file-size>    <max-request-size>418018841</max-request-size>    <file-size-threshold>1048576</file-size-threshold></multipart-config></servlet><servlet-mapping> <servlet-name>uploadfile</servlet-name> <url-pattern>/mainPage.jsp</url-pattern></servlet-mapping</web-app>