@Override
  public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

    if (checkPrerequisites(servletRequest)) {
      doFilterInternal(servletRequest, servletResponse);
    }

    filterChain.doFilter(servletRequest, servletResponse);
  }
The value for the Charset HTTP response header.
ambari-server/src/main/java/org/apache/ambari/server/security/AbstractSecurityHeaderFilter.java