网关（Gateway）- 自定义过滤器工厂

自定义过滤工厂类

DemoGatewayFilterFactory

package com.learning.springcloud.custom;import org.apache.commons.lang.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.http.HttpStatus;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;import java.util.Arrays;
import java.util.List;@Component
public class DemoGatewayFilterFactory extends AbstractGatewayFilterFactory<DemoGatewayFilterFactory.Config> {public DemoGatewayFilterFactory() {super(Config.class);}public List<String> shortcutFieldOrder() {return Arrays.asList("name", "value");}@Overridepublic GatewayFilter apply(DemoGatewayFilterFactory.Config config) {return new GatewayFilter() {public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {String value = exchange.getRequest().getQueryParams().getFirst("name");if (StringUtils.isBlank(value)) {// 为空 则证明是正常的请求 需要放行return chain.filter(exchange);}if ("YES".equals(value)) {return chain.filter(exchange);}exchange.getResponse().setStatusCode(HttpStatus.NOT_FOUND);return exchange.getResponse().setComplete();}};}public static class Config {private String name;private String value;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getValue() {return value;}public void setValue(String name) {this.value = name;}}
}

过滤器配置说明

server:port: 8088
spring:application:name: api-gatewaycloud:nacos:discovery:server-addr: 127.0.0.1:8847username: nacospassword: nacosgateway:routes:- id: order_route # 路由唯一标识#uri: http://localhost:8020 # 需要转发的地址uri: lb://order-service # 需要转发的地址# 断言规则  用于路由规则的匹配predicates:
#            - Path=/order-serv/**
#            - After=2024-01-01T23:00:11.518+08:00[Asia/Shanghai]
#            - Before=2025-01-01T23:00:11.518+08:00[Asia/Shanghai]- Between=2024-01-01T23:00:11.518+08:00[Asia/Shanghai],2025-01-01T23:00:11.518+08:00[Asia/Shanghai]
#            - Header=X-Request-Id,\d+
#            - Host=127.0.0.1
#            - Query=name,lq
#            - Method=GET,POST# http://localhost:8088/order-serv/order/add  => http://localhost:8020/order-serv/order/add- Demo=YES#配置过滤器工厂filters:- StripPrefix=1 # 转发去掉第一层路径- AddRequestHeader=X-Request-name,tom #添加请求头- AddRequestParameter=color, blue # 添加请求参数- PrefixPath=/demo
#            - RedirectTo=302, https://www.baidu.com/ #重定向到百度- Demo=name,YES  # 自定义过滤工厂配置# http://localhost:8020/order-serv/order/add => http://localhost:8020/order/add

访问效果

• 不带name参数的请求放行

• 带name参数值不是YES的拦截,返回 not found

• 带name参数值是YES的放行

实现说明 

• 命名必须需要以 FilterFactory 结尾（约定规范）
• 继承 AbstractGatewayFilterFactory 类
• 必须为spring的组件bean（@Component）
• 必须要有内部类 Config 以及 对应的 shortcutFieldOrder 方法
• 重写 apply 方法的逻辑 （apply(DemoGatewayFilterFactory.Config config)）
• 可通过 exchange.getRequest() 获取到 ServerHttpRequest 对象
• 从而获取到请求的参数、请求方式、请求头等信息