UpdateExtractSolrConfig.xml

<requestHandler name="/update/extract"
                   startup="lazy"
                   class="solr.extraction.ExtractingRequestHandler" >
  <lst name="defaults">
    <str name="lowernames">true</str>
    <str name="capture">h1</str>
    <str name="fmap.h1">heading-one</str>
    <str name="capture">h2</str>
    <str name="fmap.h2">heading-two</str>
    <str name="capture">li</str>
    <str name="fmap.li">listing</str>
  </lst>
</requestHandler>

<updateRequestProcessorChain name="remove">
   <processor class="solr.RemoveBlankFieldUpdateProcessorFactory">
   <lst name="exclude">
     <str name="fieldRegex">.*_literal</str>
   </lst>
 </processor>
</updateRequestProcessorChain>