request.getHeader中区分大小写参数

import javax.servlet.http.HttpServletRequest;
  //...
  private HttpServletRequest request;
  //get request headers
  private Map<String, String> getHeadersInfo() {
    Map<String, String> map = new HashMap<String, String>();
    Enumeration headerNames = request.getHeaderNames();
    while (headerNames.hasMoreElements()) {
        String key = (String) headerNames.nextElement();
        String value = request.getHeader(key);
        map.put(key, value);
    }
    return map;
  }