Can not find the tag library descriptor for "http://java.sun.com/jstl/core_rt"

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/fmt"

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/functions"

缺少jstl.jar,standard.jar

Can not find the tag library descriptor for "http://java.sun.com/jstl/core_rt"