MacBook + IDEA + JSP learning problem solving process

One problem: ClassNotFoundException: org.apache.commons.fileupload.FileItemFactory
solve one: go to the official website to download Apache commons-fileupload-1.3.3.jar, placed in the lib directory of the local tomcat can be solved.
Provided that already commons-fileupload-1.3.3.jar into the project, add the jar package IDEA, the reference following this blog.
https://www.cnblogs.com/mracale/p/10493823.html