缺少javax.servlet包
解决方法:
引入下面代码即可
<project>
<dependencies>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
</dependencies>
</project>
转载:https://blog.csdn.net/tomcat_2014/article/details/50292411