how to use <c:if> in jsp file. eclipse said it is unknown tag [duplicate]
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20-06-2021 - |
Pregunta
I want to write a simple web page in .jsp file. I need to use <c:if>
tag. but it is not recognized. eclipse said it is unknown tag.
I googled it and some said I need to include the standard lib (which is JSTL?).
I just want to use some basic tags in jsp file such as <c:if>
. Do I really need to include any libraries?
If so, what libraries do I need to include? And how to do that in Eclipse?
Please let me know step by step about how to import/include these libraries or build path so that I can use <c:if>
in my jsp file.
Solución
Make sure that you have a taglib declaration in your JSP file
<%@ taglib
prefix="c"
uri="http://java.sun.com/jsp/jstl/core"
%>
Also, make sure that you've added JSTL jar files to your project classpath.
Otros consejos
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>
<HTML>
<HEAD><TITLE>JSTL 'if' tag</TITLE></HEAD>
<BODY>
<c:if test="true">Hello world!</c:if>
</BODY>
</HTML>
You need to see this link JSTL tag library to select the right libraries version and its header:
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
or
<%@ taglib uri="http://java.sun.com/jstl/core" prefix="c" %>
add this tag..
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
and copy this two jar file in your project folder web-inf->lib
javax.servlet.jsp.jstl-1.2.1.jar javax.servlet.jsp.jstl-api-1.2.1.jar