java 后台获取访问客户端ip地址

 protected String getClientIpAddress(HttpServletRequest request) {
         String clientIp = request.getHeader("x-forwarded-for");
         if(clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {
             clientIp = request.getHeader("Proxy-Client-IP");
         }
         if(clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {
             clientIp = request.getHeader("WL-Proxy-Client-IP");
         }
         if(clientIp == null || clientIp.length() == 0 || "unknown".equalsIgnoreCase(clientIp)) {
             clientIp = request.getRemoteAddr();
         }
         return clientIp;
     }