1) The include directive: <%@ include file="header.html" %>

Static: adds the content from the value of the file attribute to the current page at translation time. The directive was originally intended for static layout templates, like HTML headers.
2) The <jsp:include> standard action <jsp:include page="header.jsp" />

Dynamic: adds the content from the value of the page attribute to the current page at request time. Was intended more for dynamic content coming from JSPs.
3) The <c:import> JSTL tag: <c:import url=”http://www.example.com/foo/bar.html” />

Dynamic: adds the content from the value of the URL attribute to the current page, at request time. It works a lot like <jsp:include>, but it’s more powerful and flexible: unlike the other two includes, the <c:import> url can be from outside the web Container!

ref :http://stackoverflow.com/questions/14580120/whats-the-difference-between-including-files-with-jsp-include-directive-jsp-in