SpringCloud局部过滤器自定义

一、实现步骤：

在gateway_service中编写MyParamGatewayFilterFactory类
实现业务代码：循环请求参数中是否包含name，如果包含则输出参数值
修改配置文件
访问请求测试，带name参数

二、在gateway_service中编写MyParamGatewayFilterFactory类

package com.william.filters;
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.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;
import java.util.Arrays;
import java.util.List;
/*** 命名有要求：* MyParam(自定义) GatewayFilterFactory(固定写法)*/
@Component//千万不要忘记注入Spring容器
public class MyParamGatewayFilterFactory extends AbstractGatewayFilterFactory<MyParamGatewayFilterFactory.Config> {/*** Prefix key.*/public static final String PARAM_NAME = "name";public MyParamGatewayFilterFactory() {super(Config.class);}@Overridepublic List<String> shortcutFieldOrder() {return Arrays.asList(PARAM_NAME);}public GatewayFilter apply(Config config) {GatewayFilter gatewayFilter  = new GatewayFilter() {@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {/*** 拦截所有请求，如果参数中包含name,把参数打印到控制台*///获取请求对象ServerHttpRequest request = exchange.getRequest();//获取所有参数String name = request.getQueryParams().getFirst("name");//如果name有值 = null "" "  " "   "if (!StringUtils.isEmpty(name)) {System.out.printf("局部过滤器，拦截 name=%s !!!!", name);}return chain.filter(exchange);//放行所有请求}};return gatewayFilter;}public static class Config {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}}
}