[Either `!=` or `ne` will work][1], but you need to get the [accessor syntax and nested quotes][2] sorted out.

&lt;!-- language: xhtml --&gt;

    &lt;c:if test=&quot;${content.contentType.name ne &#39;MCE&#39;}&quot;&gt;
        &lt;%-- snip --%&gt;
    &lt;/c:if&gt;


  [1]: http://docs.oracle.com/javaee/6/tutorial/doc/bnaik.html
  [2]: http://docs.oracle.com/javaee/6/tutorial/doc/bnahu.html#bnahx

I did a `bundle show` and get the complete path to a gem directory.

Unfortunately, I removed the directory using `rm -r gem_path`. Then my rails app isn&#39;t working anymore. If I try start server or start rails console it outputs the following error:

&gt; `&lt;class:Application&gt;`: uninitialized constant `MyAPP::Application::Gem` (NameError)

**What should I do to have it back?**

I tried `bundle install` or `bundle update` in hope of forcing the bundle to search the gem and install it back, but didn&#39;t work.

I also tried delete the `Gemfile.lock` and run `bundle install`. Nothing changed, same error.

The gem in question is [**Act as taggable on**][1].


[1]: http://rubygems.org/gems/acts-as-taggable-on

How to reinstall a gem using bundler

I am filtering my list using an EditText control. I want to filter the list **0.5 seconds after the user has finished typing in EditText**. I used the `afterTextChanged` event of `TextWatcher` for this purpose. But this event rises for each character changes in EditText.

What should I do?



How can I do something 0.5 seconds after text changed in my EditText control?

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?

I'm trying to only show something based on if a string is not equal to:
<pre><code class="hljs language-bash">&#x3C;c:if test="${content.getContentType().getName() != "MCE"}">
&#x3C;li>&#x3C;a href="#publish-history" id="publishHistoryTab">Publish History&#x3C;/a>&#x3C;/li>
&#x3C;/c:if>
</code></pre>
It keeps throwing the error <code>org.apache.jasper.JasperException: /WEB-INF/jsp/content/manage.jsp(14,60) PWC6212: equal symbol expected</code>
I've also tried <code>not eq</code> instead of <code>!=</code>
What is the valid syntax for <code>not equal to</code>?

I have a `Class` object. I want to determine if the type that the `Class` object represents implements a specific interface. I was wondering how this could be achieved?

I have the following code. Basically what it does is gets an array of all the classes in a specified package. I then want to go through the array and add the Class objects that implement an interface to my map. Problem is the `isInstance()` takes an object as a parameter. I can&#39;t instantiate an interface. So I am kind of at a loss with this. Any ideas?

    Class[] classes = ClassUtils.getClasses(handlersPackage);
    for(Class clazz : classes)
    {
        if(clazz.isInstance(/*Some object*/)) //Need something in this if statement
        {
            retVal.put(clazz.getSimpleName(), clazz);
        }
    }

Determine if a Class implements a interface in Java

I would like to know what is the cleanest and best way to perform form validation of user inputs. I have seen some developers implement [`org.springframework.validation.Validator`][1]. A question about that: I saw it validates a class. Does the class have to be filled manually with the values from the user input, and then passed to the validator?

I am confused about the cleanest and best way to validate the user input. I know about the traditional method of using `request.getParameter()` and then manually checking for `nulls`, but I don&#39;t want to do all the validation in my `Controller`. Some good advice on this area will be greatly appreciated. I am not using Hibernate in this application.


  [1]: http://docs.spring.io/spring-framework/docs/4.2.x/javadoc-api/org/springframework/validation/Validator.html

Spring MVC: How to perform validation?

Say I have a class with no equals() method, to which do not have the source.  I want to assert equality on two instances of that class.

I can do multiple asserts:

    assertEquals(obj1.getFieldA(), obj2.getFieldA());
    assertEquals(obj1.getFieldB(), obj2.getFieldB());
    assertEquals(obj1.getFieldC(), obj2.getFieldC());
    ...

I don&#39;t like this solution because I don&#39;t get the full equality picture if an early assert fails.

I can manually compare on my own and track the result:

    String errorStr = &quot;&quot;;
    if(!obj1.getFieldA().equals(obj2.getFieldA())) {
    	errorStr += &quot;expected: &quot; + obj1.getFieldA() + &quot;, actual: &quot; + obj2.getFieldA() + &quot;\n&quot;;
    }
    if(!obj1.getFieldB().equals(obj2.getFieldB())) {
    	errorStr += &quot;expected: &quot; + obj1.getFieldB() + &quot;, actual: &quot; + obj2.getFieldB() + &quot;\n&quot;;
    }
    ...
    assertEquals(&quot;&quot;, errorStr);

This gives me the full equality picture, but is clunky (and I haven&#39;t even accounted for possible null problems).  A third option is to use Comparator, but compareTo() will not tell me which fields failed equality.

Is there a better practice to get what I want from the object, without subclassing and overridding equals (ugh)?


How do I assert equality on two classes without an equals method?

In Swing you can simply use `setDefaultCloseOperation()` to shut down the entire application when the window is closed.

However in JavaFX I can&#39;t find an equivalent. I have multiple windows open and I want to close the entire application if a window is closed. What is the way to do that in JavaFX?

Edit:

I understand that I can override `setOnCloseRequest()` to perform some operation on window close. The question is what operation should be performed to terminate the entire application?

    stage.setOnCloseRequest(new EventHandler&lt;WindowEvent&gt;() {
        @Override
        public void handle(WindowEvent event) {
    	    stop();
        }
    });

The `stop()` method defined in `Application` class does nothing.

How to close a JavaFX application on window close?

How to convert or cast hashmap to JSON object in Java, and again convert JSON object to JSON string?

How to convert hashmap to JSON object in Java

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 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;

It seems that there are two methods for templating with JSP. Including files with one of these statements 

    &lt;%@ include file=&quot;foo.html&quot; %&gt;
    &lt;jsp:include page=&quot;foo.html&quot; /&gt;

or using JSP tag files 

    // Save this as mytag.tag
    &lt;%@ tag description=&quot;Description&quot; pageEncoding=&quot;UTF-8&quot;%&gt;
    &lt;html&gt;
    &lt;head&gt;
    &lt;/head&gt;
    &lt;body&gt;
        &lt;jsp:doBody/&gt;
    &lt;/body&gt;
    &lt;/html&gt;

And in another JSP page call it with

    &lt;%@ taglib prefix=&quot;t&quot; tagdir=&quot;/WEB-INF/tags&quot; %&gt;
        
    &lt;t:mytag&gt;
        &lt;h1&gt;Hello World&lt;/h1&gt;
    &lt;/t:mytag&gt;

So which method should I use? Is one now considered deprecated or are they both valid and cover different use cases?

**Edit**

Isn&#39;t using this tag file the same as using an include?

    // Save this as product.tag
    &lt;%@ tag description=&quot;Product templage&quot; pageEncoding=&quot;UTF-8&quot;%&gt;
    &lt;%@ tag import=&quot;com.myapp.Product&quot; %&gt;
    &lt;%@ attribute name=&quot;product&quot; required=&quot;true&quot; type=&quot;com.myapp.Product&quot;%&gt;
    
    Product name: ${product.name} &lt;br/&gt;
    Quantity: ${product.quantity} &lt;br/&gt;

And call it on another JSP with

    &lt;%@ taglib prefix=&quot;t&quot; tagdir=&quot;/WEB-INF/tags&quot; %&gt;
    
    &lt;t:product&gt;
        &lt;c:forEach items=&quot;${cart.products}&quot; var=&quot;product&quot;&gt;
            &lt;t:product product=&quot;${product}&quot;/&gt;
        &lt;/c:forEach&gt;
    &lt;/t:product&gt;

That seems to me to be the very same as using an include and passing parameters to it. So are Tag Files the same as includes?

What&#39;s the difference between including files with JSP include directive, JSP include action and using JSP Tag Files?

I have the following code setting a variable in my controller:

    model.set(&quot;type&quot;, type);

In the thymeleaf view I want to construct a form with action url:

    /mycontroller/{type}

Any ideas how to achieve this? I&#39;ve read thymeleaf documentation with no luck.

Thymeleaf construct URL with variable

I am developing web app using spring frame work, but i am getting following error in some of the jsp pages.

    javax.servlet.ServletException cannot be resolved to a type

I have included `servlet-api` also but still same error message is displaying. How to over come this problem?

javax.servlet.ServletException cannot be resolved to a type in spring web app

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

Can not find the tag library descriptor for “http://java.sun.com/jsp/jstl/core”

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

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!

Content Type	Original Author	Original Content on Stackoverflow
Question	Ben	View Question on Stackoverflow
Solution 1 - Java	Matt Ball	View Answer on Stackoverflow

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

Java Problem Overview

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Solution 1 - Java

How can I do something 0.5 seconds after text changed in my EditText control?

How to reinstall a gem using bundler

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