code: public void process(final Exchange exchange) throws Exception {
          final Message in = exchange.getIn();
  
          final String contentType = in.getHeader(CONTENT_TYPE, "", String.class);
          final String body = in.getBody(String.class);
          final Set<String> endpoints = new HashSet<>();
  
          for (final String s : in.getHeader(REINDEXING_RECIPIENTS, "", String.class).split(",")) {
              endpoints.add(s.trim());
          }
  
          if (contentType.equals("application/json") && body != null && !body.trim().isEmpty()) {
              try {
                  final JsonNode root = MAPPER.readTree(body);
                  final Iterator<JsonNode> ite = root.elements();
                  while (ite.hasNext()) {
                      final JsonNode n = ite.next();
                      endpoints.add(n.asText());
                  }
              } catch (JsonProcessingException e) {
                  LOGGER.debug("Invalid JSON", e);
                  in.setHeader(HTTP_RESPONSE_CODE, BAD_REQUEST);
                  in.setBody("Invalid JSON");
              }
          }
          in.setHeader(REINDEXING_RECIPIENTS, join(",", endpoints));
      }
docs: Convert the incoming REST request into the correct
  Fcrepo header fields.
  
  @param exchange the current message exchange