添加白名单黑名单的目的是控制请求

使用拦截器或者过滤器都是可以的！

以下主要是使用拦截器（Interceptor）

1.先要能获取到IP，所以需要一个ip工具类

public class IPUtils {
    /**
     * 获取用户真实IP地址，不使用request.getRemoteAddr()的原因是有可能用户使用了代理软件方式避免真实IP地址,
     * 可是，如果通过了多级反向代理的话，X-Forwarded-For的值并不止一个，而是一串IP值
     * @return ip
     */
    public static String getRealIP(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip != null && ip.length() != 0 && !"unknown".equalsIgnoreCase(ip)) {
            // 多次反向代理后会有多个ip值，第一个ip才是真实ip
            if( ip.indexOf(",")!=-1 ){
                ip = ip.split(",")[0];
            }
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
            System.out.println("Proxy-Client-IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
            System.out.println("WL-Proxy-Client-IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
            System.out.println("HTTP_CLIENT_IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
            System.out.println("HTTP_X_FORWARDED_FOR ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("X-Real-IP");
            System.out.println("X-Real-IP ip: " + ip);
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
            System.out.println("getRemoteAddr ip: " + ip);
        }
        return ip;
    }
}

2.创建一个拦截器去实现拦截，这里我想的是从配置文件读取，常规的@value是无法直接获取到的，所以需要先通过注解@Compont实现拦截器注册给spring管理，再通过set的办法赋值

public class IPInterceptor implements HandlerInterceptor {


    private static String ipWhite;

    @Value("${ip.white}")
    public void setIpWhite(String ipWhite) {
        IPInterceptor.ipWhite = ipWhite;
    }

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println(ipWhite);
        if(StringUtils.isBlank(ipWhite)) return true;//全部不拦截
        String[] split = {};
        if(ipWhite.contains(",")){
            split = ipWhite.split(",");
        }else {
             split = new String[]{ipWhite};
         }
        List<String> list = Arrays.asList(split);
        //获取请求的IP
        String realIP = IPUtils.getRealIP(request);
        if(!list.contains(realIP))return false; //非指定IP 拦截不通过
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        HandlerInterceptor.super.postHandle(request, response, handler, modelAndView);
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        HandlerInterceptor.super.afterCompletion(request, response, handler, ex);
    }
}

3.最后一步也是最关键的一步，让我们的拦截器生效是要把拦截器注册进来

@Configuration //拦截器注册进来
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new IPInterceptor())
                .addPathPatterns("/test/*");
    }
}