code: public static String readCorrelationId(Message message) {
          String correlationId = null;
          Map<String, List<String>> headers = getOrCreateProtocolHeader(message);
          List<String> correlationIds = headers.get(CORRELATION_ID_KEY);
          if (correlationIds != null && correlationIds.size() > 0) {
              correlationId = correlationIds.get(0);
              if (LOG.isLoggable(Level.FINE)) {
                  LOG.fine("HTTP header '" + CORRELATION_ID_KEY + "' found: " + correlationId);
              }
          } else {
              if (LOG.isLoggable(Level.FINE)) {
                  LOG.fine("No HTTP header '" + CORRELATION_ID_KEY + "' found");
              }
          }
  
          return correlationId;
      }
docs: Read correlation id from message.
  
  @param message the message
  @return the CorrelationId as string