jstl – Page 4 – Tarik Billa

Ternary operator in JSTL/EL

June 14, 2023 by Tarik

I tested the following page in Tomcat 5.59, JSP 2.0 and JSTL 1.1. It ran without any errors. <%@taglib uri=”http://java.sun.com/jsp/jstl/core” prefix=”c”%> <c:set var=”value” scope=”request” value=”someValue”/> <c:out default=”None” escapeXml=”true” value=”${not empty value ? value : ‘None’}” /> <c:out default=”None” escapeXml=”true” value=”${empty value ? ‘None’ : value}” /> <c:set var=”value” scope=”request” value=”” /> <br/> <c:out default=”None” escapeXml=”true” … Read more

How to call parameterized method from JSP using JSTL/EL

June 2, 2023 by Tarik

You can only invoke methods with arguments in EL if you’re targeting and running at least a Servlet 3.0 compatible container (e.g. Tomcat 7 or newer, WildFly 8 or newer, GlassFish 3 or newer, etc) with a web.xml declared conform at least Servlet 3.0. This servlet version comes along with EL 2.2 which allows invoking … Read more

Checking attribute exists in JSP

June 1, 2023 by Tarik

Make use of JSTL c:catch. <c:catch var=”exception”>${myObject.myAttribute}</c:catch> <c:if test=”${not empty exception}”>Attribute not available.</c:if>

How to compare two object variables in EL expression language?

May 31, 2023 by Tarik

In Expression Language you can just use the == or eq operator to compare object values. Behind the scenes they will actually use the Object#equals(). This way is done so, because until with the current EL 2.1 version you cannot invoke methods with other signatures than standard getter (and setter) methods (in the upcoming EL … Read more

How can I replace newline characters using JSP and JSTL?

May 30, 2023 by Tarik

Here is a solution I found. It doesn’t seem very elegant, though: <%@ taglib prefix=”fn” uri=”http://java.sun.com/jsp/jstl/functions” %> <% pageContext.setAttribute(“newLineChar”, “\n”); %> ${fn:replace(item.comments, newLineChar, “; “)}

Tomcat 7 and JSTL

May 19, 2023 by Tarik

I have been fighting with this for several hours. Here is a complete solution. I am using Tomcat 7, which is a Servlet 3.0-compliant server. If you desire to use the Servlet 3.0 spec, you must have your web.xml as follows: <web-app xmlns=”http://java.sun.com/xml/ns/javaee” xmlns:xsi=”http://www.w3.org/2001/XMLSchema-instance” xsi:schemaLocation=”http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd” version=”3.0″> If you’re using Maven, your pom.xml should have … Read more

Check if parameter exists in Expression Language [duplicate]

May 19, 2023 by Tarik

Use the not empty check. <c:if test=”${not empty param.username}” > </c:if> Edit: If you have a parameter of the form ?username (no value), it is safer to use ${param.username ne null}

javax.servlet.jsp.PageContext cannot be resolved to a type [duplicate]

May 15, 2023 by Tarik

You will need to import in your project the JSP APIs, which are not included in servlet-api In my project, the solution is: <dependency> <groupId>javax.servlet.jsp</groupId> <artifactId>jsp-api</artifactId> <version>2.1</version> <scope>provided</scope> </dependency>

The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application

April 28, 2023 by Tarik

Remove the standard.jar. It’s apparently of old JSTL 1.0 version when the TLD URIs were without the /jsp path. With JSTL 1.2 as available here you don’t need a standard.jar at all. Just the jstl-1.2.jar in /WEB-INF/lib is sufficient. See also: How to install JSTL? The absolute uri: http://java.sun.com/jstl/core cannot be resolved Our JSTL wiki … Read more

Get value from hashmap based on key to JSTL

April 27, 2023 by Tarik

if all you’re trying to do is get the value of a single entry in a map, there’s no need to loop over any collection at all. simplifying gautum’s response slightly, you can get the value of a named map entry as follows: <c:out value=”${map[‘key’]}”/> where ‘map’ is the collection and ‘key’ is the string … Read more