You can have a look at the EL (expression language) description here. Both your code are correct, but I prefer the second one, as comparing a boolean to true or false is redundant. For better readibility, you can also use the not operator: <c:if test=”${not theBooleanVariable}”>It’s false!</c:if>
This look like a duplicate of JSTL conditional check. The error is having the && outside the expression. Instead use <c:if test=”${ISAJAX == 0 && ISDATE == 0}”>
EL 3.0 or newer If you’re already on Java EE 7 / EL 3.0, then the @page import will also import class constants in EL scope. <%@ page import=”com.example.YourConstants” %> This will under the covers be imported via ImportHandler#importClass() and be available as ${YourConstants.FOO}. Note that all java.lang.* classes are already implicitly imported and available … Read more
The variable set by varStatus is a LoopTagStatus object, not an int. Use: <div id=”divIDNo${theCount.index}”> To clarify: ${theCount.index} starts counting at 0 unless you’ve set the begin attribute ${theCount.count} starts counting at 1
Yes, since some genius in the Java API creation committee decided that, even though certain classes have size() members or length attributes, they won’t implement getSize() or getLength() which JSF and most other standards require, you can’t do what you want. There’s a couple ways to do this. One: add a function to your Bean … Read more
Jun 2002: JSTL 1.0 was introduced with EL for first time. It were those ${} things which works in JSTL tags only. It is designed to call Javabean get methods. Nov 2003: JSP 2.0 was introduced and EL was moved from JSTL 1.0 to JSP 2.0 in javax.servlet.jsp.el package and it became standard EL as … Read more
1. Target Unreachable, identifier ‘bean’ resolved to null This boils down to that the managed bean instance itself could not be found by exactly that identifier (managed bean name) in EL like so #{bean}. Identifying the cause can be broken down into three steps: a. Who’s managing the bean? b. What’s the (default) managed bean … Read more
This is caused by the nature of deferred expressions #{} (note that “legacy” standard expressions ${} behave exactly the same when Facelets is used instead of JSP). The deferred expression is not immediately evaluated, but created as a ValueExpression object and the getter method behind the expression is executed everytime when the code calls ValueExpression#getValue(). … Read more
How can I validate if a String is null or empty using the c tags of JSTL? You can use the empty keyword in a <c:if> for this: <c:if test=”${empty var1}”> var1 is empty or null. </c:if> <c:if test=”${not empty var1}”> var1 is NOT empty or null. </c:if> Or the <c:choose>: <c:choose> <c:when test=”${empty var1}”> … Read more