Spring Cloud Gateway限流（一）

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

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

spring:
  redis:
    host: localhost
    port: 6379

public class RedisRateLimiterGatewayFilterFactory extends AbstractGatewayFilterFactory<RedisRateLimiterGatewayFilterFactory.Config> {

    private final RedisTemplate<String, String> redisTemplate;

    public RedisRateLimiterGatewayFilterFactory(RedisTemplate<String, String> redisTemplate) {
        super(Config.class);
        this.redisTemplate = redisTemplate;
    }

    @Override
    public GatewayFilter apply(Config config) {
        return (exchange, chain) -> {
            String key = exchange.getRequest().getHeaders().getFirst(config.getHeader());
            if (key == null) {
                throw new IllegalArgumentException("Header " + config.getHeader() + " not found");
            }
            String redisKey = config.getKeyResolver().apply(exchange);
            String permits = redisTemplate.opsForValue().get(redisKey);
            if (permits == null) {
                redisTemplate.opsForValue().set(redisKey, String.valueOf(config.getPermits()));
                redisTemplate.expire(redisKey, config.getDuration());
            } else {
                int remaining = Integer.parseInt(permits) - 1;
                if (remaining < 0) {
                    throw new RateLimiterException();
                }
                redisTemplate.opsForValue().set(redisKey, String.valueOf(remaining));
            }
            return chain.filter(exchange);
        };
    }

    public static class Config {
        private String header = "X-RateLimit-Header";
        private int permits = 10;
        private Duration duration = Duration.ofSeconds(1);
        private Function<ServerWebExchange, String> keyResolver = exchange -> exchange.getRequest().getPath().toString();

        public String getHeader() {
            return header;
        }

        public void setHeader(String header) {
            this.header = header;
        }

        public int getPermits() {
            return permits;
        }

        public void setPermits(int permits) {
            this.permits = permits;
        }

        public Duration getDuration() {
            return duration;
        }

        public void setDuration(Duration duration) {
            this.duration = duration;
        }

        public Function<ServerWebExchange, String> getKeyResolver() {
            return keyResolver;
        }

        public void setKeyResolver(Function<ServerWebExchange, String> keyResolver) {
            this.keyResolver = keyResolver;
        }
    }

    public static class RateLimiterException extends RuntimeException {
        public RateLimiterException() {
            super("Rate limit exceeded");
        }
    }
}