How to use

appendHeader

method

in

org.apache.camel.http.common.HttpHelper

protected void populateRequestParameters(HttpServletRequest request, HttpMessage message) throws Exception {
  //we populate the http request parameters without checking the request method
  Map<String, Object> headers = message.getHeaders();
  Enumeration<?> names = request.getParameterNames();
  while (names.hasMoreElements()) {
    String name = (String)names.nextElement();
    // there may be multiple values for the same name
    String[] values = request.getParameterValues(name);
    LOG.trace("HTTP parameter {} = {}", name, values);
    if (values != null) {
      for (String value : values) {
        if (headerFilterStrategy != null
          && !headerFilterStrategy.applyFilterToExternalHeaders(name, value, message.getExchange())) {
          HttpHelper.appendHeader(headers, name, value);
        }
      }
    }
  }
}

protected void readHeaders(HttpServletRequest request, HttpMessage message) {
  LOG.trace("readHeaders {}", request);
  Map<String, Object> headers = message.getHeaders();
  //apply the headerFilterStrategy
  Enumeration<?> names = request.getHeaderNames();
  while (names.hasMoreElements()) {
    String name = (String)names.nextElement();
    String value = request.getHeader(name);
    // use http helper to extract parameter value as it may contain multiple values
    Object extracted = HttpHelper.extractHttpParameterValue(value);
    // mapping the content-type
    if (name.toLowerCase().equals("content-type")) {
      name = Exchange.CONTENT_TYPE;
    }
    if (headerFilterStrategy != null
        && !headerFilterStrategy.applyFilterToExternalHeaders(name, extracted, message.getExchange())) {
      HttpHelper.appendHeader(headers, name, extracted);
    }
  }
  if (request.getCharacterEncoding() != null) {
    headers.put(Exchange.HTTP_CHARACTER_ENCODING, request.getCharacterEncoding());
    message.getExchange().setProperty(Exchange.CHARSET_NAME, request.getCharacterEncoding());
  }
  try {
    populateRequestParameters(request, message);
  } catch (Exception e) {
    throw new RuntimeCamelException("Cannot read request parameters due " + e.getMessage(), e);
  }
}

if (headerFilterStrategy != null
    && !headerFilterStrategy.applyFilterToExternalHeaders(name, value, message.getExchange())) {
  HttpHelper.appendHeader(headers, name, value);

HttpHelper.appendHeader(headers, name, value);
if (getHeaderFilterStrategy() != null
  && !getHeaderFilterStrategy().applyFilterToExternalHeaders(name, value, message.getExchange())) {
  HttpHelper.appendHeader(headers, name, value);

HttpHelper.appendHeader(answer.getHeaders(), name, extracted);