<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
报错library descriptor for "http://java.sun.com/jsp/jstl/ core"
正确的做法是准备好jar包jstl.jar、standard-1.1.2.jar，把jar放到WEB-INF/lib里面就可以了
参考：https://blog.csdn.net/kolamemo/article/details/51407467
https://blog.csdn.net/u012251836/article/details/53881738
