src/main/java/org/jboss/net/protocol/file/FileURLConnection.java
public String getHeaderField(final String name)
   {
      String headerField = null;
      if (name.equalsIgnoreCase("last-modified"))
      {
         long lastModified = getLastModified();
         if (lastModified != 0)
         {
            // return the last modified date formatted according to RFC 1123
            Date modifiedDate = new Date(lastModified);
            SimpleDateFormat sdf = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'", Locale.US);
            sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
            headerField = sdf.format(modifiedDate);
         }
      }
      else if (name.equalsIgnoreCase("content-length"))
      {
         headerField = String.valueOf(file.length());
      }
      else if (name.equalsIgnoreCase("content-type"))
      {
         if (file.isDirectory())
         {
            headerField = "text/plain";
         }
         else
         {
            headerField = getFileNameMap().getContentTypeFor(file.getName());
            if (headerField == null)
            {
               try
               {
                  InputStream is = getInputStream();
                  BufferedInputStream bis = new BufferedInputStream(is);
                  headerField = URLConnection.guessContentTypeFromStream(bis);
                  bis.close();
               }
               catch(IOException e)
               {
                  // ignore
               }
            }
         }
      }
      else if (name.equalsIgnoreCase("date"))
      {
         headerField = String.valueOf(getLastModified());
      }
      else
      {
         // This always returns null currently
         headerField = super.getHeaderField(name);
      }
      return headerField;
   }
public String getHeaderField(final String name)
   {
      String headerField = null;
      if (name.equalsIgnoreCase("last-modified"))
      {
         long lastModified = getLastModified();
         if (lastModified != 0)
         {
            // return the last modified date formatted according to RFC 1123
            Date modifiedDate = new Date(lastModified);
            SimpleDateFormat sdf = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss 'GMT'", Locale.US);
            sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
            headerField = sdf.format(modifiedDate);
         }
      }
      else if (name.equalsIgnoreCase("content-length"))
      {
         headerField = String.valueOf(file.length());
      }
      else if (name.equalsIgnoreCase("content-type"))
      {
         if (file.isDirectory())
         {
            headerField = "text/plain";
         }
         else
         {
            headerField = getFileNameMap().getContentTypeFor(file.getName());
            if (headerField == null)
            {
               try
               {
                  InputStream is = getInputStream();
                  BufferedInputStream bis = new BufferedInputStream(is);
                  headerField = URLConnection.guessContentTypeFromStream(bis);
                  bis.close();
               }
               catch(IOException e)
               {
                  // ignore
               }
            }
         }
      }
      else if (name.equalsIgnoreCase("date"))
      {
         headerField = String.valueOf(getLastModified());
      }
      else
      {
         // This always returns null currently
         headerField = super.getHeaderField(name);
      }
      return headerField;
   }
Provides support for the following headers:

<tt>last-modified</tt>
<tt>content-length</tt>
<tt>content-type</tt>
<tt>date</tt>