E.g.

    &lt;c:if test=&quot;${post}&quot;&gt;
    	&lt;h3&gt;${post.title}&lt;/h3&gt;	
    &lt;/c:if&gt;



How can i check if an attribute is set (not null and not an empty string) with jstl?

The following code causes an error:

	 &lt;c:set var=&quot;test&quot; value=&quot;test1&quot;/&gt;
	 &lt;%
	   String resp = &quot;abc&quot;;
       resp = resp + test;
	   pageContext.setAttribute(&quot;resp&quot;, resp);
	 %&gt;
	 &lt;c:out value=&quot;${resp}&quot;/&gt;

The error says 

    &quot;error a line 4: unknown symbol &#39;test&#39;&quot;.

How do I pass `test` from the JSTL code to the JSP scriptlet?

I can pass a variable from a JSP scriptlet to JSTL but not from JSTL to a JSP scriptlet without an error

I have a JSP file and in that file I am including another JSP file:

    &lt;c:forEach var=&quot;instanceVar&quot; items=&quot;${instanceList}&quot;&gt;
        &lt;c:set var=&quot;instance&quot;&gt;&lt;jsp:include page=&quot;instance.jsp&quot;/&gt;&lt;/c:set&gt;
        ...
    &lt;/c:forEach

&lt;br&gt;
In the file _instance.jsp_ I want to use a variable `instanceVar`. I want to do it using JSTL. Is there any way to do this?



Passing parameters to another JSP file using &lt;jsp:include&gt; tag

I want to output some HTML code based on some condition in a JSP file.

&lt;!-- language: none --&gt;

    if (condition 1) {
        Some HTML code specific for condition 1
    }
    else if (condition 2) {
        Some HTML code specific for condition 2
    }

How can I do that? Should I use JSTL?



if...else within JSP or JSTL

I have a java class that sets an servlet attribute to a HashMap object:

    request.setAttribute(&quot;types&quot;, da.getSecurityTypes());

where `request` is an HttpServletRequest Object, and `da.getSecurityTypes()` returns a HashMap Object.

Is there a way to go through the HashMap collection using c:foreach or some other JSTL tags?

I was thinking:   

     &lt;c:forEach var=&quot;type&quot; items=&quot;${types}&quot;&gt;
                     ...
         &lt;/c:forEach&gt;
Or if it can&#39;t be done, how would one make a custom tag to process this?

Resorting to Java code in my JSP page is be my last resort and I&#39;d like to know if this is possible with JSTL.

Thanks,
Jonas.

Use &lt;c:forEach&gt; with HashMap

I have a text to render in three different possible colors using **thymeleaf**.

So the code I&#39;ve made so far to test the value is:

    th:if=&quot;${evaluation} &amp;gt; 50&quot;
    th:if=&quot;${evaluation} &amp;lt; 30&quot;

And that works well.

But the third test is for values between those two.
So I tried:

    th:if=&quot;(${evaluation} &amp;lt; 49) &amp;and; (${evaluation} &amp;gt; 29)&quot;

but it&#39;s not working, I&#39;ve got this error while parsing:

    org.thymeleaf.exceptions.TemplateProcessingException: Could not parse as expression: &quot;(${evaluation} &lt; 49) &amp;and; (${evaluation} &gt; 29)&quot; (/property.html:41)

Of course, these lines are between tags since the first two are working properly.

Maybe the and operand is not correct, but the documentation of thymeleaf is not really explicit on those operands.

All ideas are welcome!


**Update:** I got the answer from the thymeleaf forum. The way to do it is:

    th:if=&quot;${evaluation &amp;lt; 49 and evaluation &amp;gt; 29}&quot;

Problem solved!

How to have multiple condition in an th:if tag using thymeleaf

is it possible to do something like this in JSTL:

    &lt;div class=&quot;firstclass&lt;c:if test=&#39;true&#39;&gt; someclass&lt;/c:if&gt;&quot;&gt;
       &lt;p&gt;some other stuff...&lt;/p&gt;
    &lt;/div&gt;

Is there any way to get this to work, or is there a better way to add a class by looking at a JSTL-if-statement?

JSTL if-statement inside HTML-attribute

I managed to do it with the next code but there must be an easier way. 

    &lt;%@ taglib prefix=&quot;c&quot; uri=&quot;http://java.sun.com/jsp/jstl/core&quot; %&gt;
    &lt;%@ taglib prefix=&quot;fn&quot; uri=&quot;http://java.sun.com/jsp/jstl/functions&quot; %&gt;
    
    
    &lt;c:if test=&quot;${fn:length(attachments) &gt; 0}&quot;&gt;
        &lt;c:forEach var=&quot;attachment&quot; items=&quot;${attachments}&quot; varStatus=&quot;loopCount&quot;&gt;
            &lt;c:if test=&quot;${loopCount.count eq 1}&quot;&gt;
    	     attachment.id
            &lt;/c:if&gt;
        &lt;/c:forEach&gt;
    &lt;/c:if&gt;

How to select the first element of a set with JSTL?

I am using JDK 1.7, Apache Tomcat 7.0.23 and I have placed JSTL core library(1.2) and STANDARD jar in WEB_INF lib folder it is not giving me any warning but when I will try to run the code 

&lt;!-- language: lang-html --&gt;

    &lt;%@ taglib uri=&quot;http://java.sun.com/jsp/jstl/core&quot; prefix=&quot;c&quot; %&gt;
    &lt;!DOCTYPE html PUBLIC &quot;-//W3C//DTD HTML 4.01 Transitional//EN&quot; &quot;http://www.w3.org/TR/html4/loose.dtd&quot;&gt;
    &lt;!-- Create Bean Instance--&gt;
    &lt;jsp:useBean id=&quot;listdomain&quot; class=&quot;bean.PopulateMultiDomain&quot; scope=&quot;session&quot;&gt;&lt;/jsp:useBean&gt;
    
    &lt;jsp:setProperty property=&quot;*&quot; name=&quot;listdomain&quot;/&gt;
    
    &lt;c:forEach var=&quot;item&quot; items=&quot;${listdomain.status}&quot;&gt;
        &lt;option&gt;
            &lt;c:out value=&quot;${item}&quot; /&gt;
        &lt;/option&gt;
    &lt;/c:forEach&gt; 

it gives me the following error:

&lt;!-- language: none --&gt;

    org.apache.jasper.JasperException: 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
    	org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:56)
    	org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:410)
    	org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:117)
    	org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:311)
    	org.apache.jasper.compiler.TagLibraryInfoImpl.&lt;init&gt;(TagLibraryInfoImpl.java:152)
    	org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:410)
    	org.apache.jasper.compiler.Parser.parseDirective(Parser.java:475)
    	org.apache.jasper.compiler.Parser.parseElements(Parser.java:1425)
    	org.apache.jasper.compiler.Parser.parse(Parser.java:138)
    	org.apache.jasper.compiler.ParserController.doParse(ParserController.java:242)
    	org.apache.jasper.compiler.ParserController.parse(ParserController.java:102)
    	org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
    	org.apache.jasper.compiler.Compiler.compile(Compiler.java:373)
    	org.apache.jasper.compiler.Compiler.compile(Compiler.java:353)
    	org.apache.jasper.compiler.Compiler.compile(Compiler.java:340)
    	org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:646)
    	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:357)
    	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
    	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
    	javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

Can anyone suggest me what mistake I am making?

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

I want to get the value of `HashMap` based on key.&lt;br&gt;

    HashMap&lt;String, ArrayList&lt;String&gt;&gt; map 
        = new HashMap&lt;String, ArrayList&lt;String&gt;&gt;();
    ArrayList&lt;String&gt; arrayList = new ArrayList&lt;String&gt;();
        
    map.put(&quot;key&quot;, arrayList);
    request.setAttribute(&quot;key&quot;, map);

What i did is&lt;br&gt;

    &lt;c:forEach var=&quot;map&quot; items=&quot;${requestScope.key}&quot;&gt;
    	&lt;c:forEach var=&quot;hash&quot; items=&quot;${map.value}&quot;&gt;
    		&lt;option&gt;&lt;c:out value=&quot;${hash}&quot;/&gt;&lt;/option&gt;
    	&lt;/c:forEach&gt;
    &lt;/c:forEach&gt;

But it seems it&#39;s printing everything, what i want to do is to get the value depends on key like: `hash.key` or something

&lt;b&gt;UPDATE:&lt;/b&gt;&lt;br&gt;
I did something like this but it still doesn&#39;t work

    &lt;c:forEach var=&quot;map&quot; items=&quot;${requestScope.key}&quot;&gt;
        &lt;c:forEach var=&quot;hash&quot; items=&quot;${map[&#39;key&#39;]}&quot;&gt;
            &lt;option&gt;&lt;c:out value=&quot;${hash}&quot;/&gt;&lt;/option&gt;
        &lt;/c:forEach&gt;
    &lt;/c:forEach&gt;

and the StackTrace: `Property &#39;External&#39; not found on type java.util.HashMap$Entry` &lt;br&gt;
I&#39;m pretty sure that there is really that kind of key.

Get value from hashmap based on key to JSTL

When I am run my application after entering the URL, this exception is coming.I am using Eclipse and Tomcat7.0.35. I also added Jstl.jar and jstl1.2.jar

My code is

    java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config
    	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
    	at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
    	at org.apache.myfaces.view.jsp.JspViewDeclarationLanguage.buildView(JspViewDeclarationLanguage.java:91)
    	at org.apache.myfaces.lifecycle.RenderResponseExecutor.execute(RenderResponseExecutor.java:78)
    	at org.apache.myfaces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:241)
    	at javax.faces.webapp.FacesServlet.service(FacesServlet.java:199)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
    	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)
    	at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:936)
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
    	at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1004)
    	at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)
    	at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:310)
    	at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    	at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    	at java.lang.Thread.run(Unknown Source)




java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config

How can I check the size of a collection with JSTL?

Something like:

    &lt;c:if test=&quot;${companies.size() &gt; 0}&quot;&gt;
    
    &lt;/c:if&gt;

Check a collection size with JSTL

I would like to output a bit of Facelets code conditionally.

For that purpose, the JSTL tags seem to work fine:

&lt;!-- language: xhtml --&gt;

    &lt;c:if test=&quot;${lpc.verbose}&quot;&gt;
        ...
    &lt;/c:if&gt;

However, I&#39;m not sure if this is a best practice?  Is there another way to achieve my goal?

JSTL in JSF2 Facelets... makes sense?

I don&#39;t know what I&#39;ve done incorrectly, but I can&#39;t include JSTL. I have jstl-1.2.jar, but unfortunately I get exception: 

&lt;!-- language: none --&gt;

    org.apache.jasper.JasperException: The absolute uri: http://java.sun.com/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
    	at org.apache.jasper.compiler.DefaultErrorHandler.jspError(DefaultErrorHandler.java:51)
    	at org.apache.jasper.compiler.ErrorDispatcher.dispatch(ErrorDispatcher.java:409)
    	at org.apache.jasper.compiler.ErrorDispatcher.jspError(ErrorDispatcher.java:116)
    	at org.apache.jasper.compiler.TagLibraryInfoImpl.generateTLDLocation(TagLibraryInfoImpl.java:315)
    	at org.apache.jasper.compiler.TagLibraryInfoImpl.&lt;init&gt;(TagLibraryInfoImpl.java:148)
    	at org.apache.jasper.compiler.Parser.parseTaglibDirective(Parser.java:429)
    	at org.apache.jasper.compiler.Parser.parseDirective(Parser.java:492)
    	at org.apache.jasper.compiler.Parser.parseElements(Parser.java:1439)
    	at org.apache.jasper.compiler.Parser.parse(Parser.java:137)
    	at org.apache.jasper.compiler.ParserController.doParse(ParserController.java:255)
    	at org.apache.jasper.compiler.ParserController.parse(ParserController.java:103)
    	at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:170)
    	at org.apache.jasper.compiler.Compiler.compile(Compiler.java:332)
    	at org.apache.jasper.compiler.Compiler.compile(Compiler.java:312)
    	at org.apache.jasper.compiler.Compiler.compile(Compiler.java:299)
    	at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586)
    	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317)
    	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342)
    	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267)
    	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
    	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
    	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
    	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
    	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
    	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
    	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
    	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
    	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:849)
    	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
    	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:454)
    	at java.lang.Thread.run(Thread.java:619)

I have:

-   `pom.xml`
    
        &lt;dependency&gt;
          &lt;groupId&gt;javax.servlet&lt;/groupId&gt;
          &lt;artifactId&gt;servlet-api&lt;/artifactId&gt;
          &lt;version&gt;2.5&lt;/version&gt;
          &lt;scope&gt;provided&lt;/scope&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
          &lt;groupId&gt;javax.servlet.jsp&lt;/groupId&gt;
          &lt;artifactId&gt;jsp-api&lt;/artifactId&gt;
          &lt;version&gt;2.1&lt;/version&gt;
          &lt;scope&gt;provided&lt;/scope&gt;
        &lt;/dependency&gt;
    
        &lt;dependency&gt;
          &lt;groupId&gt;taglibs&lt;/groupId&gt;
          &lt;artifactId&gt;standard&lt;/artifactId&gt;
          &lt;version&gt;1.1.2&lt;/version&gt;
        &lt;/dependency&gt;
        &lt;dependency&gt;
          &lt;groupId&gt;javax.servlet&lt;/groupId&gt;
          &lt;artifactId&gt;jstl&lt;/artifactId&gt;
          &lt;version&gt;1.2&lt;/version&gt;
        &lt;/dependency&gt;
    
-    `web.xml`
    
        &lt;web-app xmlns=&quot;http://java.sun.com/xml/ns/javaee&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
          xsi:schemaLocation=&quot;http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd&quot;
          version=&quot;2.5&quot;&gt;
    
-   `index.jsp`
    
        &lt;%@ taglib uri=&quot;http://java.sun.com/jstl/core&quot; prefix=&quot;c&quot; %&gt;
        &lt;html&gt; 
        &lt;head&gt;&lt;/head&gt;
        &lt;body&gt;&lt;/body&gt;
        &lt;/html&gt;



How to install JSTL? The absolute uri: http://java.sun.com/jstl/core cannot be resolved

What&#39;s the best way to do a simple `if`-`else` in Thymeleaf?

I want to achieve in Thymeleaf the same effect as

    &lt;c:choose&gt;
      &lt;c:when test=&quot;${potentially_complex_expression}&quot;&gt;
         &lt;h2&gt;Hello!&lt;/h2&gt;
      &lt;/c:when&gt;
      &lt;c:otherwise&gt;
         &lt;span class=&quot;xxx&quot;&gt;Something else&lt;/span&gt;
      &lt;/c:otherwise&gt;
    &lt;/c:choose&gt;

in JSTL.

What I&#39;ve figured so far:

&lt;!-- language: lang-html --&gt;

    &lt;div th:with=&quot;condition=${potentially_complex_expression}&quot; th:remove=&quot;tag&quot;&gt;
        &lt;h2 th:if=&quot;${condition}&quot;&gt;Hello!&lt;/h2&gt;
        &lt;span th:unless=&quot;${condition}&quot; class=&quot;xxx&quot;&gt;Something else&lt;/span&gt;
    &lt;/div&gt;

I don&#39;t want to evaluate `potentially_complex_expression` twice. That&#39;s why I introduced local variable `condition`. Still I don&#39;t like using both `th:if=&quot;${condition}` and `th:unless=&quot;${condition}&quot;`.

An important thing is that I use two different HTML tags: let&#39;s say `h2` and `span`.

Can you suggest a better way to achieve it?


How to do if-else in Thymeleaf?

I&#39;m looking to have JSTL loop through a `Map&lt;String, String&gt;` and output the value of the key and it&#39;s value.

For example I have a `Map&lt;String, String&gt;` which can have any number of entries, i&#39;d like to loop through this map using JSTL and output both the key and it&#39;s value.

I know how to access the value using the key, `${myMap[&#39;keystring&#39;]}`, but how do I access the key?

Loop through a Map with JSTL

I&#39;ve been trying to evaluate if this array list is empty or not but none of these have even compiled:

    &lt;c:if test=&quot;${myObject.featuresList.size == 0 }&quot;&gt;					
    &lt;c:if test=&quot;${myObject.featuresList.length == 0 }&quot;&gt;					
    &lt;c:if test=&quot;${myObject.featuresList.size() == 0 }&quot;&gt;					
    &lt;c:if test=&quot;${myObject.featuresList.length() == 0 }&quot;&gt;					
    &lt;c:if test=&quot;${myObject.featuresList.empty}&quot;&gt;					
    &lt;c:if test=&quot;${myObject.featuresList.empty()}&quot;&gt;					
    &lt;c:if test=&quot;${myObject.featuresList.isEmpty}&quot;&gt;	

How can I evaluate if an ArrayList is empty?				


Evaluate if list is empty JSTL

How would I get the length of an `ArrayList` using a JSF EL expression? 

    #{MyBean.somelist.length}

does not work.

How do you get the length of a list in the JSF expression language?

I have a value set in the `request` object like the following,

    String[] categoriesList=null;
    categoriesList = engine.getCategoryNamesArray();
    request.setAttribute(&quot;categoriesList&quot;, categoriesList );

and this is how I iterate in jsp page

    &lt;% if(request.getAttribute(&quot;categoriesList&quot;) != null) { %&gt;
    &lt;c:forEach var=&quot;categoryName&quot; items=&quot;${categoriesList}&quot;&gt;
       &lt;li&gt;&lt;a onclick=&quot;getCategoryIndex()&quot; href=&quot;#&quot;&gt;${categoryName}&lt;/a&gt;&lt;/li&gt;
    &lt;/c:forEach&gt;
    &lt;% }%&gt;

How do I get index of each element and pass it to JavaScript function `onclick=&quot;getCategoryIndex()&quot;`.


How to get a index value from foreach loop in jstl

Writing a JSP page, what exactly does the `&lt;c:out&gt;` do? I&#39;ve noticed that the following both has the same result:

    &lt;p&gt;The person&#39;s name is &lt;c:out value=&quot;${person.name}&quot; /&gt;&lt;/p&gt;
    &lt;p&gt;The person&#39;s name is ${person.name}&lt;/p&gt;



JSP : JSTL&#39;s &lt;c:out&gt; tag

I want to use the count from the JSTL forEach loop, but my code doesnt seem to work.

    &lt;c:forEach items=&quot;${loopableObject}&quot; var=&quot;theObject&quot; varStatus=&quot;theCount&quot;&gt;
        &lt;div id=&quot;divIDNo${theCount}&quot;&gt;
        &lt;/div&gt;
    &lt;/c:forEach&gt;

produces 

    &lt;div id=&quot;divIDNojavax.servlet.jsp.jstl.core.LoopTagSupport$1Status@5570e2&quot; &gt;



Use JSTL forEach loop&#39;s varStatus as an ID

I have an Enum called Status defined as such:

    public enum Status { 
  
        VALID(&quot;valid&quot;), OLD(&quot;old&quot;);
    
        private final String val;

        Status(String val) {
            this.val = val;
        }
    
        public String getStatus() {
            return val;
        }

    }

I would like to access the value of `VALID` from a JSTL tag. Specifically the `test` attribute of the `&lt;c:when&gt;` tag. E.g.

    &lt;c:when test=&quot;${dp.status eq Status.VALID&quot;&gt;

I&#39;m not sure if this is possible.

Access Enum value using EL with JSTL

How do I check two conditions in one `&lt;c:if&gt;`? I tried this, but it raises an error:

    &lt;c:if test=&quot;${ISAJAX == 0} &amp;&amp; ${ISDATE == 0}&quot;&gt; 



How do I check two or more conditions in one &lt;c:if&gt;?

    &lt;%@ taglib prefix=&quot;c&quot; uri=&quot;http://java.sun.com/jsp/jstl/core&quot; %&gt;
    &lt;%@ page import=&quot;com.library.controller.*&quot;%&gt;
    &lt;%@ page import=&quot;com.library.dao.*&quot; %&gt;
    &lt;%@ page import=&quot;java.util.*&quot; %&gt;
    &lt;%@ page import=&quot;java.lang.*&quot; %&gt;
    &lt;%@ page import=&quot;java.util.Date&quot; %&gt;
    &lt;meta http-equiv=&quot;Content-Type&quot; content=&quot;text/html; charset=ISO-8859-1&quot;&gt;
    &lt;title&gt;Return Page&lt;/title&gt;
    &lt;/head&gt;
    &lt;body bgcolor=&quot;#aabcde&quot;&gt;
    &lt;div align=&quot;right&quot;&gt;&lt;a href=&quot;Login.jsp&quot;&gt;Logout&lt;/a&gt;&lt;/div&gt;
    &lt;table align=&quot;center&quot; border=&quot;2&quot; cellspacing=&quot;3&quot; cellpadding=&quot;3&quot;&gt;
    &lt;tr&gt;&lt;th&gt;BookID&lt;/th&gt;&lt;th&gt;BookName&lt;/th&gt;&lt;th&gt;Issuedate&lt;/th&gt;&lt;th&gt;returndate&lt;/th&gt;&lt;/tr&gt;
    &lt;c:forEach var=&quot;element&quot; items=&quot;${list}&quot;&gt;
        &lt;tr&gt;
            &lt;td&gt;${element.getBookid}&lt;/td&gt;&lt;td&gt;${element.getBookname()}&lt;/td&gt;  
            &lt;td&gt;${element.getIssuedate()}&lt;/td&gt;&lt;td&gt;${element.getReturndate()}&lt;/td&gt;
        &lt;/tr&gt;
    &lt;/c:forEach&gt;
The Eclipse IDE is showing red underline and when I focus it the tag is : can not find the library descriptor for http://java.sun.com/jsp/jstl/core

How to resolve : Can not find the tag library descriptor for &quot;http://java.sun.com/jsp/jstl/core&quot;

I need to hide an element if certain values are present in the JSP 

The values are stored in a List so I tried:


    &lt;c:if test=&quot;${  mylist.contains( myValue ) }&quot;&gt;style=&#39;display:none;&#39;&lt;/c:if&gt;

But, it doesn&#39;t work. 

How can I evaluate if a list contains a value in JSTL, the list and the values are strings.


Evaluate list.contains string in JSTL

I&#39;ve got a variable from an object on my JSP page:

`&lt;%= ansokanInfo.getPSystem() %&gt;`

The value of the variable is NAT which is correct and I want to apply certain page elements for this value. How do I use a tag to know the case? I tried something like

	

    &lt;c:if test = &quot;${ansokanInfo.getPSystem() == &#39;NAT&#39;}&quot;&gt;      
       process  
    &lt;/c:if&gt; 

But the above doesn&#39;t display anything. How should I do it? Or can I just as well use scriptlets i.e.

	&lt;% if (ansokanInfo.getPSystem().equals(&quot;NAT&quot;){ %&gt;
	process
	&lt;% } %&gt;
Thanks for any answer or comment. 

JSTL if tag for equal strings

I have a Map keyed by Integer. Using EL, how can I access a value by its key?

    Map&lt;Integer, String&gt; map = new HashMap&lt;Integer, String&gt;();
    map.put(1, &quot;One&quot;);
    map.put(2, &quot;Two&quot;);
    map.put(3, &quot;Three&quot;);

I thought this would work but it doesn&#39;t (where map is already in the request&#39;s attributes):

    &lt;c:out value=&quot;${map[1]}&quot;/&gt;

**Follow up:** I tracked down the problem. Apparently `${name[1]}` does a map lookup with the number as a `Long`. I figured this out when I changed `HashMap` to `TreeMap` and received the error:

    java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Long

If I change my map to be:

    Map&lt;Long, String&gt; map = new HashMap&lt;Long, String&gt;();
    map.put(1L, &quot;One&quot;);

then `${name[1]}` returns &quot;One&quot;. What&#39;s with that? Why does `&lt;c:out&gt;` treat a number as a long. Seems counterintuitive to me (as int is more commonly used than long).

So my new question is, is there a EL notation to access a map by an `Integer` value?

EL access a map value by Integer key

How can I validate if a `String` is null or empty using the `c` tags of `JSTL`?

I have a variable of name `var1` and I can display it, but I want to add a comparator to validate it.

    &lt;c:out value=&quot;${var1}&quot; /&gt;

I want to validate when it is null or empty (my values are strings).

Evaluate empty or null JSTL c tags

I&#39;m trying to only show something based on if a string is not equal to:


    &lt;c:if test=&quot;${content.getContentType().getName() != &quot;MCE&quot;}&quot;&gt;
    &lt;li&gt;&lt;a href=&quot;#publish-history&quot; id=&quot;publishHistoryTab&quot;&gt;Publish History&lt;/a&gt;&lt;/li&gt;
    &lt;/c:if&gt;

It keeps throwing the error `org.apache.jasper.JasperException: /WEB-INF/jsp/content/manage.jsp(14,60) PWC6212: equal symbol expected`

I&#39;ve also tried `not eq` instead of `!=`

What is the valid syntax for `not equal to`?

How do I compare if a string is not equal to?

This question is related to my previous question :

https://stackoverflow.com/questions/4729183/jsp-iterate-trough-object-list

I want to insert counter that starts from 0 in my for loop, I&#39;ve tried several combinations so far :

#1. 

    &lt;c:forEach var=&quot;tableEntity&quot; items=&#39;${requestScope.tables}&#39;&gt;
       &lt;c:forEach var=&quot;rowEntity&quot; items=&#39;${tableEntity.rows}&#39; varStatus=&quot;count&quot;&gt;    		
    		&lt;c:out value=&quot;${count}&quot; /&gt;
        &lt;/c:forEach&gt;
    &lt;/c:forEach&gt;

#2. 

    &lt;c:set var=&quot;count&quot; value=&quot;0&quot; scope=&quot;page&quot; /&gt;
    &lt;c:forEach var=&quot;tableEntity&quot; items=&#39;${requestScope.tables}&#39;&gt;
       &lt;c:forEach var=&quot;rowEntity&quot; items=&#39;${tableEntity.rows}&#39;&gt;      
       &lt;%=count++%&gt;  
    &lt;c:out value=&quot;${count}&quot; /&gt;
        &lt;/c:forEach&gt;
    &lt;/c:forEach&gt;

Problem with first approach is that outer loop has 3 items and inner loop has 7 items, so for each outer item the count starts from 0. The second one I get compile error. Here is basically what I want :

    counter = 0;
    outer for loop 
        inner for loop 
           counter++;
           //cout/echo/print counter value should start from 0
        end inner loop
    end outer loop

I&#39;m just not totally familiar with the syntax. thank you


Increment counter with loop

trying to use this jstl to formulate a json string, how can i make the segment not to put a comma in the end of the last record? note the comma in the end

    &lt;c:forEach items=&quot;${fileList}&quot; var=&quot;current&quot;&gt;
        { id:1001,data:[&quot;&lt;c:out value=&quot;${current.fileName}&quot; /&gt;&quot; , &quot;&lt;c:out value=&quot;${current.path}&quot; /&gt;&quot; , &quot;&lt;c:out value=&quot;${current.size}&quot; /&gt;&quot; , &quot;&lt;c:out value=&quot;${current.type}&quot; /&gt;&quot;] },
    &lt;/c:forEach&gt;

jstl foreach omit an element in last record

I am using a JSP page to print an array of values. I&#39;m trying to use JSTL `&lt;c:forEach&gt;` for this.

    &lt;c:forEach items=&quot;${objects}&quot; var=&quot;object&quot;&gt;
        &lt;td&gt;${object.name} &lt;/td&gt;
    &lt;/c:forEach&gt;

The problem is my JSTL taglib declaration:

     &lt;%@ taglib prefix=&quot;c&quot; uri=&quot;http://java.sun.com/jsp/jstl/core&quot;%&gt;

The IDE shows an error on this line

&gt; Can not find the tag library descriptor.

Many of the forums point to the old Sun site to download the JSTL libraries. Now all of these links point to the Oracle home page with no link to JSTL binaries. This is leading me to believe there is a newer approach to accomplish this.

Sun JSTL taglib declaration fails with &quot;Can not find the tag library descriptor&quot;

Is there an if-else tag available in JSTL?

How to use if-else option in JSTL

Does anyone know because all the places I&#39;ve tried seem to timeout!

Where can I download JSTL jar

Currently I use:

    &lt;%
    final String message = (String) request.getAttribute (&quot;Error_Message&quot;);
    %&gt;

and then

    &lt;%= message %&gt;

However I wonder if the same can be done with EL or JSTL instead of using a scriptlet.

How to access at request attributes in JSP?

I would like to concatenate a string within a ternary operator in EL(Expression Language).

Suppose there is a variable named value. If it&#39;s empty, I want to use some default text. Otherwise, I need to append it with some static text.

    ${(empty value)? &quot;none&quot; : value + &quot; enabled&quot;}

This will not compile however. What would be a correct way to write this? Or is this even possible?

String Concatenation in EL

If I have a JSF backing bean return an object of type ArrayList, I should be able to use `&lt;c:foreach&gt;` to iterate over the elements in the list.  Each element contains a map and although the question of how to access the map content through JSTL has been answered [here][1], if I pass an array of such maps, I can&#39;t find how to iterate over them and still access the map content using JSTL.  There&#39;s documentation which refers to simple iterators but not to those whose items are themselves maps.

If anyone can give me a simple example of how a java List is iterated over in JSP I&#39;d be massively appreciative.
Mark

  [1]: https://stackoverflow.com/questions/2141464/how-to-access-complex-java-maps-in-jsf-richfaces

Iterate over elements of List and Map using JSTL &lt;c:forEach&gt; tag

I need a while loop within JSTL. I cannot seem to find how to loop over something a specified number of times. Any ideas how I can accomplish this?

I am thinking I could use a forEach but I do not really care to loop over a collection.

How to loop over something a specified number of times in JSTL?

I have included this at the very top of my JSP page:

    &lt;%@ taglib prefix=&quot;c&quot; uri=&quot;http://java.sun.com/jsp/jstl/core&quot; %&gt;

I already placed the JSTL JAR file in the `WEB-INF/lib` directory. But still, the JSP can&#39;t resolve the taglib. I get the below error:

&gt; Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core”

I am using Eclipse Juno and the project structure is shown below:

![enter image description here][1]


  [1]: http://i.stack.imgur.com/pEj8S.png

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