如何区分Ajax请求和普通的Http请求？

Ajax请求通常具有一个

X-Requested-With:XMLHttpRequest

ExternalContext#getRequestHeaderMap()

ExternalContext externalContext = facesContext.getExternalContext();Map<String, String> headers = externalContext.getRequestHeaderMap();boolean ajax = "XMLHttpRequest".equals(headers.get("X-Requested-With"));