title: How to link a form path with a static map key in SpringMVC?
body: <p>I have an object FileDTO containing a static Map (Map).</p>
  
  <pre><code>public class FileDTO implements Serielizable {
  
      private Map&lt;String, MultipartFile&gt; fileMap;
  
      public Map&lt;String, MultipartFile&gt; getFileMap() {
          return fileMap;
      }
  
      public void setFileMap(Map&lt;String, MultipartFile&gt; fileMap) {
          this.fileMap= fileMap;
      }
  }
  </code></pre>
  
  <p>I linked my form to FileDTO using modelAttribute tag.</p>
  
  <pre><code>&lt;form:form modelAttribute="fileDTO"&gt;
  ....
  &lt;/form:form&gt;
  </code></pre>
  
  <p>I try to send an entry via this form but the fileMap is null.</p>
  
  <pre><code>&lt;form:input type="file" id="${inputName}" name="${inputName}" 
      path="${fileMap[inputName]}" /&gt;
  </code></pre>
  
  <p>The controller is a PostMapping having the parameter ModelAttribute FileDTO fileDTO.</p>
  
  <p>Do you have any idea?</p>
  
  <p>Thank you in advance</p>