title: request.getParameterNames() is empty after setting the form's enctype to "multipart/form-data"
body: <p>Im developing a simple file upload using JSP, everything works fine until I set the form's enctype to "multipart/form-data", <code>request.getParameterNames()</code> is returning empty. Any idea?</p>
  
  <p>Here's my code:</p>
  
  <p>upload.jsp</p>
  
  <pre><code>&lt;%@page contentType="text/html" pageEncoding="UTF-8"%&gt;
  &lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;
          &lt;title&gt;File Upload&lt;/title&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;form method="POST" action="login.jsp" enctype="multipart/form-data"&gt;
              &lt;input type="text" name="name" placeholder="File Name"&gt;&lt;/input&gt;
              &lt;br&gt;
              &lt;input type="file" name="file" id="file"&gt;&lt;/input&gt;
              &lt;br&gt;&lt;br&gt;
              &lt;input type="submit" name="submit" id="submit" value="Submit"&gt;&lt;/input&gt;
          &lt;/form&gt;
      &lt;/body&gt;
      &lt;/html&gt;
  </code></pre>
  
  <p>login.jsp</p>
  
  <pre><code>&lt;%@page import="java.util.Enumeration"%&gt;
  &lt;%@page import="java.io.InputStream"%&gt;
  &lt;!DOCTYPE html&gt;
  &lt;html&gt;
      &lt;head&gt;
          &lt;meta http-equiv="Content-Type" content="text/html; charset=UTF-8"&gt;
          &lt;title&gt;JSP Page&lt;/title&gt;
      &lt;/head&gt;
      &lt;body&gt;
          &lt;%
              Enumeration params = request.getParameterNames();
              boolean empty = true;
              while(params.hasMoreElements()){
                  String param = params.nextElement().toString();
                  out.println(param);
                  empty = true;
              }
              if(empty) out.println("No parameters received!");
          %&gt;
      &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>