package com.it.filter;import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.SneakyThrows;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;/*** 网关里面 通过设置过滤器进行ip拦截* ip拦截：* 请求都有一个来源* 请求-->gateway-->service* 黑名单：具体的业务服务用黑名单* 白名单：访问数据库用白名单，防止别人恶意访问*/
public class IPCheckFilter implements GlobalFilter, Ordered {/*** 网关的并发量比较高，不要在网关里面直接操作mysql* 后台的系统可以查询数据库 用户量  并发量不大* 如果并发量大  可以查看redis  或则在内存中写好*/public static final List<String> BACK_LIST= Arrays.asList("127.0.0.1","192.168.12.115");/*** 1.拿到ip* 2.校验ip是否符合规范* 3.放行或则拦截* @param exchange* @param chain* @return*/@SneakyThrows@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {ServerHttpRequest request = exchange.getRequest();String ip= request.getHeaders().getHost().getHostString();//查询数据库，看这个ip是否存在在黑名单里面if (!BACK_LIST.contains(ip)){//放行return chain.filter(exchange);}//拦截ServerHttpResponse response = exchange.getResponse();response.getHeaders().set("content-type","application/json;charset=utf-8");HashMap<String, Object> map = new HashMap<>(4);map.put("code", 438);map.put("msg","你是黑名单");ObjectMapper objectMapper = new ObjectMapper();byte[] bytes = objectMapper.writeValueAsBytes(map);DataBuffer wrap = response.bufferFactory().wrap(bytes);return response.writeWith(Mono.just(wrap));}@Overridepublic int getOrder() {return -5;}
}

一般把token放在请求头里面，请求头里面是key-value结构，key统一设置成Authorization  value统一设置成 bearer token

1.拿到请求的url

2.判断放行

3.拿到请求头

4.拿到token

5.在redis中校验

6.放行或拦截