Servlet过滤器：如何从ServletRequest中获取所有标头？

类型转换

ServletRequest

HttpServletRequest

ServletRequestrequest

instanceof

HttpServletRequest

然后可以使用

HttpServletRequest.getHeader()

HttpServletRequest.getHeaderNames()

像这样：

@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {    HttpServletRequest httpRequest = (HttpServletRequest) request;    Enumeration<String> headerNames = httpRequest.getHeaderNames();    if (headerNames != null) { while (headerNames.hasMoreElements()) {         System.out.println("Header: " + httpRequest.getHeader(headerNames.nextElement())); }    }    //doFilter    chain.doFilter(httpRequest, response);}