web.xml is missing and <failOnMissingWebXml> is set to true

1、错误描述
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>com.you.cup</groupId>
<artifactId>CUP</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>

</project>

web.xml is missing and <failOnMissingWebXml> is set to true

2、错误原因
      由错误提示可知，缺少web.xml文件

3、解决办法
（1）选中项目，鼠标右键，点击“Java EE Tools”
（2）选择“Generate Deployment Descriptor Sub”，生成WEB-INF文件夹和web.xml