final String mimeType = responseData.getMimeType();
        if (logger.isDebugEnabled()) {
            logger.debug("mimeType: {}", mimeType);
        }
        if (mimeType == null) {
            response.contentTypeOctetStream();
            return;
        }
        if (mimeType.startsWith("text/")) {
            final String charset = responseData.getCharSet();

}

private fun Main.mediaType(): MediaType? {
  val mimeType =
    headers?.let {
      for (header in it) {
        val parts = header.split(':', limit = 2)
        if ("Content-Type".equals(parts[0], ignoreCase = true)) {
          return@let parts[1].trim()
        }
      }
      return@let null
    } ?: "application/x-www-form-urlencoded"

  return mimeType.toMediaTypeOrNull()
}

        }
        return buf.toString();
    }

    /**
     * Sets the MIME type.
     * @param mimeType The MIME type.
     */
    public void setMimeType(final String mimeType) {
        this.mimeType = mimeType;
    }

                case FessConfig.INDEX_FIELD_FILETYPE:
                    return "filetype";
                case FessConfig.INDEX_FIELD_FILENAME:
                    return "filename";
                case FessConfig.INDEX_FIELD_THUMBNAIL:
                    return "thumbnail";
                case FessConfig.INDEX_FIELD_MIMETYPE:
                    return "mimetype";

                // Crawler settings

      },
      "filetype": {
        "type": "keyword"
      },
      "host": {
        "type": "keyword"
      },
      "lang": {
        "type": "keyword"
      },
      "last_modified": {
        "type": "date",
        "format": "date_optional_time"
      },
      "location": {
        "type": "geo_point"
      },
      "mimetype": {
        "type": "keyword"
      },

      },
      "filetype": {
        "type": "keyword"
      },
      "host": {
        "type": "keyword"
      },
      "lang": {
        "type": "keyword"
      },
      "last_modified": {
        "type": "date",
        "format": "date_optional_time"
      },
      "location": {
        "type": "geo_point"
      },
      "mimetype": {
        "type": "keyword"
      },

		documents which has "Fess" as the document title, you can enter:
		<pre>title:Fess</pre>
		The available fields are "url", "host", "site", "title", "content",
		"content_length", "last_modified" and "mimetype", and they are
		customizable.
	</dd>
	<dt>Sort</dt>
	<dd>
		sort field sorts documents by a specified field name. The format is
		"sort:&lt;field&gt;.&lt;order&gt;", where &lt;order&gt; is asc or

            }

            @Override
            public String getIndexFieldMimetype() {
                return "mimetype";
            }

            @Override
            public String getIndexFieldFiletype() {
                return "filetype";
            }

            @Override
            public String getIndexFieldFilename() {
                return "filename";
            }

        fileTypeHelper.add("text/plain", "text");

        assertEquals("pdf", fileTypeHelper.get("application/pdf"));
        assertEquals("text", fileTypeHelper.get("text/plain"));

        // Test non-existent mimetype returns default value
        assertEquals("others", fileTypeHelper.get("non/existent"));
    }

    public void test_get_withNullMimetype() {
        assertEquals("others", fileTypeHelper.get(null));
    }

    default boolean isHtmlMimetypeForCache(final String mimetype) {
        final String[] mimetypes = getCrawlerDocumentCacheHtmlMimetypes().split(",");
        if (mimetypes.length == 1 && StringUtil.isBlank(mimetypes[0])) {
            return true;
        }
        return stream(mimetypes).get(stream -> stream.anyMatch(s -> s.equalsIgnoreCase(mimetype)));
    }

    String getCrawlerDocumentCacheSupportedMimetypes();