SpringCloud Gateway鉴权

参考：https://blog.csdn.net/weixin_43296313/article/details/121126811
基于从前的项目：https://www.cnblogs.com/xsj1989/p/18350213
在网关项目下创建全局过滤器

package com.xcg.filters;

import com.auth0.jwt.interfaces.Claim;
import com.auth0.jwt.interfaces.DecodedJWT;
import com.xcg.common.JwtUtil;
import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.Map;
@Component
public class AuthorizeFilter implements GlobalFilter, Ordered {
    //自定密钥，最好搞长一点
    public static final String TokenKey = "8FA593CF2445AB0A0AF1F173641583AB";
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        //1. 获取请求
        ServerHttpRequest request = exchange.getRequest();
        //2. 则获取响应
        ServerHttpResponse response = exchange.getResponse();
        //3. 如果是登录请求则放行
        if (request.getURI().getPath().contains("/UserLogin")) {
            return chain.filter(exchange);
        }
        //4. 获取请求头
        HttpHeaders headers = request.getHeaders();
        //5. 请求头中获取令牌
        String token = headers.getFirst("Authorization");
        //6. 判断请求头中是否有令牌
        if (StringUtils.isEmpty(token)) {
            //7. 响应中放入返回的状态吗, 没有权限访问
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            //8. 返回
            return response.setComplete();
        }
        token = token.toString().replace("Bearer ","");

        //9. 如果请求头中有令牌则解析令牌
        try {
            //校验token，不正确会报异常。
            DecodedJWT verify = JwtUtil.verify(token);
            Map<String, Claim> claims = verify.getClaims();
            var sysUserId = Integer.parseInt(claims.get("SysUserId").asString());
            if (sysUserId > 0){
                //其他判断，例如权限。
            }
        } catch (Exception e) {
            e.printStackTrace();
            //10. 解析jwt令牌出错, 说明令牌过期或者伪造等不合法情况出现
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            //11. 返回
            return response.setComplete();
        }
        //12. 放行
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}

第三步排除掉免登录的请求，其他请求都会校验登录票证。不通过就返回401状态码。