我们在开发系统的时候可能会对系统进行限流的需求， springcloudGateway有自带限流的方案，在此之前可以先去学习一下springcloud gateway中的filter。

springcloud Gateway中提供了一个RequestRateLimiterGatewayFilterFactory。这种限流方式用到了redis， 先添加redis的依赖。

配置类如下：

public class RemoteAddrKeyResolver implements KeyResolver {    public static final String BEAN_NAME = "remoteAddrKeyResolver";    @Override    public Mono
    
      resolve(ServerWebExchange exchange) {        System.out.println("hello");        Mono
     
       just = Mono.just(exchange.getRequest().getRemoteAddress().getAddress().getHostAddress());        return just;    }}
     
    

@Configurationpublic class RemoteKeyResolver {    @Bean(name="remoteAddrKeyResolver")    public RemoteAddrKeyResolver remoteAddrKeyResolver() {        return new RemoteAddrKeyResolver();    }}

在此我们是根据ip地址限流的， Mono<String> just = Mono.just(exchange.getRequest().getRemoteAddress().getAddress().getHostAddress())

application.yml配置文件配置如下：

spring:  application:    name: gateway-service#  redis:#    database: 0#    host: localhost#    port: 6379#    password:#    timeout: 1000ms#    lettuce:#      pool:#        max-active: 8#        max-idle: 8#        min-idle: 1#        max-wait: 1000ms#  cache:#    type: REDIS  cloud:    gateway:      discovery:        locator:          enabled: true      routes:        - id: order          uri: lb://order-service          predicates:          - Path=/api/order-service/**          filters:          - StripPrefix=1          - name: RequestRateLimiter            args:              key-resolver: '#{@remoteAddrKeyResolver}'              redis-rate-limiter.replenishRate: 1              redis-rate-limiter.burstCapacity: 2

上面贴出的是完整的springcloud Gateway的配置, 主要配置为filters下的-RequestRateLimiter,

key-resolver表示使用名为remoteAddKeyResolver的限流配置配置类，此限流方式采用的是令牌桶算法的限流方式redis-rate-limiter.repleushRate ：令牌桶每秒填充平均速率。redis-rate-limiter.burstCapacity: 令牌桶的总容量