对于Facelets 1.x，您需要在以下XML名称空间中声明JSTL核心标记库:

For Facelets 1.x, you need to declare the JSTL core taglib in the following XML namespace:

xmlns:c="http://java.sun.com/jstl/core"

请注意，Facelets 1.x的URI中没有/jsp.

Please note that there's no /jsp in the URI for Facelets 1.x.