title: Parameter 'directory' is not a directory for a parameter which is a directory
body: <p>I'm getting a strange error where the parameter I supply to a method complains that it's not a directory but it IS in fact a directory with files in it...I don't understand what's wrong...</p>
  
  <p><strong>Toplevel:</strong></p>
  
  <pre><code>public static File mainSchemaFile = new File("src/test/resources/1040.xsd");
  public static File contentDirectory = new File("src/test/resources/input");
  public static File outputDirectory = new File("src/test/resources/output");
  
  
  DecisionTableBuilder builder =constructor.newInstance(log, contentDirectory, outputDirectory);
  
  // Here is where the error occurs
  builder.compile(mainSchemaFile);
  </code></pre>
  
  <p><strong>The class I'm using:</strong></p>
  
  <pre><code>public class DecisionTableBuilder {
  
     public void compiler(File schemaFile) {
        ...
        // It's complaining about contentDirectory, it goes to FileUtils class for this
        Collection&lt;File&gt; flowchartFiles = FileUtils.listFiles(contentDirectory, mapExtension, true);
        ...
     }
  }
  </code></pre>
  
  <p><strong>Here is the apache FileUtils class:</strong></p>
  
  <pre><code>public class FileUtils {
  
      private static void validateListFilesParameters(File directory, IOFileFilter fileFilter) {
          if (!directory.isDirectory()) {
              throw new IllegalArgumentException("Parameter 'directory' is not a directory");
          }
          if (fileFilter == null) {
              throw new NullPointerException("Parameter 'fileFilter' is null");
          }
      }
  
  }
  </code></pre>
  
  <p>Output: Parameter 'directory' is not a directory</p>
  
  <p>Which is the error output I am getting...</p>
  
  <p>Anyone have any idea what is happening here I'm super confused...any help will be greatly appreciated. </p>
  
  <p><strong>EDIT:</strong></p>
  
  <p>In my toplevel I added the following line:</p>
  
  <pre><code>if(contentDirectory.isDirectory()) {
      System.out.println("Content Directory: "+contentDirectory);
  }
  
  Output: src/test/resources/input
  </code></pre>