To use the JSTL tag library, keep in mind this:
To use an EL-based JSTL library, you must declare the library using a taglib directive, similar to declaring a regular custom tag library:
<@ taglib prefix="c" uri="http://java.sun.com/jstl/core">
Similarly, to use a runtime-based JSTL tag library, you must declare the library using a taglib directive:
<@ taglib prefix="c_rt" uri="http://java.sun.com/jstl/core_rt">