title: Struts2, String null check
body: <p>I'm trying to do a null check on a String but it won't work.</p>
  
  <pre><code>&lt;s:iterator value="matrix" var="row"&gt;
      &lt;tr&gt;
         &lt;s:iterator value="value" var="col"&gt;
              &lt;td&gt;    
                  &lt;s:if test="%{#col==null}"&gt;0&lt;/s:if&gt;
                  &lt;s:else&gt;&lt;s:property value="col"/&gt;&lt;/s:else&gt;
              &lt;/td&gt;
          &lt;/s:iterator&gt;
      &lt;/tr&gt;
  &lt;/s:iterator&gt;
  </code></pre>
  
  <p>matrix is a</p>
  
  <pre><code>Map&lt;Integer, List&lt;String&gt;&gt;
  </code></pre>
  
  <p>The var "col" is correctly assigned a String value from the List.<br>
  The list may look like this [ "hello" , null , "world ] </p>
  
  <p>Current output: hello world<br>
  Wanted output: hello <strong>0</strong> world</p>
  
  <p>/Thanks in advance</p>