Customize the gateway filter factory on the specified route

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Preface : The core API

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One 、 demand ： Intercept request , Print log

1. Plus dependence

<dependency>
   <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

2. Create custom filters factory

import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractNameValueGatewayFilterFactory;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;

@Slf4j
@Component
// The name of the custom filter factory should start with GatewayFilterFactory ending , Just prefix it , And match the prefix to the configuration file 
public class PreLogGatewayFilterFactory extends AbstractNameValueGatewayFilterFactory {
    
    @Override
    public GatewayFilter apply(NameValueConfig config) {
    

        return ((exchange, chain) -> { // The parameters written on the configuration are config.getName(),config.getValue() Come and get it  //config.getName() Get is a,config.getValue() Get is b log.info(" The request came in , Parameters :{},{}",config.getName(),config.getValue());

            //Request.mutate You can modify the request , After modification build()
            ServerHttpRequest modifiedRequest = exchange.getRequest().mutate().build();
            // Put the modified Request to Exchange
            ServerWebExchange modifiedExchange = exchange.mutate().request(modifiedRequest).build();
            // Continue to the next filter 
            return chain.filter(modifiedExchange);
        });
    }
}

3. Add configuration

spring:
  application:
    name: gateway
  cloud:
    nacos:
      discovery:
        server-addr: localhost:8848
    gateway:
      discovery:
        locator:
          enabled: true # Give Way gateway stay nacos Find wechat 
      routes:
        - id: before_route
          uri: lb://user-center #lb :nacos Microservices on 
          predicates:
            - MyTimeBetween= In the morning 9:00, Afternoon 11:00 # Specify a routing rule , there MyTimeBetween Is custom , have access to spring-cloud-gateway Self contained .
          filters:
            - PreLog=a,b # Just write a prefix , The following is the parameters passed to the factory 

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4. verification

adopt gateway Access to microservices , The premise is that the request path needs to meet routes Predicate of , Will walk into this factory .

http://localhost:8040/users/1