如何为Spring Cloud Gateway加上全局过滤器

@Component

public class AuthFilter implements GlobalFilter, Ordered {

   @Override

   public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

     String token = exchange.getRequest().getHeaders().getFirst( "Authorization" );

     //不为空则通过

     if (!StringUtils.isEmpty(token)) return chain.filter(exchange);

     ServerHttpResponse response = exchange.getResponse();

     // 封装错误信息

     Map<String, Object> responseData = Maps.newHashMapWithExpectedSize( 3 );

     responseData.put( "code" , HttpStatus.UNAUTHORIZED.value());

     responseData.put( "message" , "Token is empty" );

     responseData.put( "cause" , "Token is empty" );

     // 将信息转换为 JSON

     ObjectMapper objectMapper = new ObjectMapper();

     byte [] data = new byte [ 0 ];

     try {

       data = objectMapper.writeValueAsBytes(responseData);

     } catch (JsonProcessingException e) {

       e.printStackTrace();

     }

     // 返回错误信息json

     DataBuffer buffer = response.bufferFactory().wrap(data);

     response.setStatusCode(HttpStatus.UNAUTHORIZED);

     response.getHeaders().add( "Content-Type" , "application/json;charset=UTF-8" );

     return response.writeWith(Mono.just(buffer));

   }

   //最后执行

   @Override

   public int getOrder() {

     return Ordered.LOWEST_PRECEDENCE;

   }

}

<!--Redis begin-->

< dependency >

   < groupId >org.springframework.boot</ groupId >

   < artifactId >spring-boot-starter-data-redis</ artifactId >

</ dependency >

< dependency >

   < groupId >org.springframework.boot</ groupId >

   < artifactId >spring-boot-starter-data-redis-reactive</ artifactId >

</ dependency >

< dependency >

   < groupId >redis.clients</ groupId >

   < artifactId >jedis</ artifactId >

</ dependency >

<!--Redis end-->

@Configuration

public class RedisConfig {

   @Bean

   public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {

     RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();

     StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();

     redisTemplate.setKeySerializer(stringRedisSerializer);

     redisTemplate.setHashKeySerializer(stringRedisSerializer);

     redisTemplate.setValueSerializer( new Jackson2JsonRedisSerializer<Object>(Object. class ));

     redisTemplate.setHashValueSerializer( new GenericJackson2JsonRedisSerializer());

     redisTemplate.setConnectionFactory(connectionFactory);

     return redisTemplate;

   }

}

@Configuration

public class GatewayRateLimiterConfig {

   /**

    * Gateway通过内置的RequestRateLimiter过滤器实现限流，用的是令牌桶算法，借助Redis保存中间数据

    * 这里自定义一个KeyResolver

    * 作用是对来源ip进行限流

    */

   @Bean (value = "ipKeyResolver" )

   public KeyResolver ipKeyResolver() {

     return exchange -> Mono.just(exchange.getRequest().getRemoteAddress().getAddress().getHostAddress());

   }

}

spring:

  application:

   # 应用名称

   name: sc-demo-alibaba-gateway

  cloud:

   nacos:

    discovery:

     server-addr: 192.168.3.105:8848 #注册进nacos

   # 使用 Sentinel 作为熔断器

   sentinel:

    transport:

     port: 18102

     dashboard: 192.168.3.105:8858

   # 路由网关配置

   gateway:

    # 这里是设置与服务注册发现组件结合，这样可以采用服务名的路由策略

    discovery:

     locator:

      enabled: true

    # 配置路由规则

    routes:

     - id : ROUTER #sc-demo-alibaba-consumer #这个是路由ID，需要保证在所有路由定义中唯一，值随便写就是了

      # 采用 LoadBalanceClient 方式请求，以 lb:// 开头，后面的是注册在 Nacos 上的服务名

      uri: lb: //sc-demo-alibaba-consumer

      predicates:

       # Method ，这里是匹配 GET 和 POST 请求

       - Method=GET,POST

      filters:

       - name: RequestRateLimiter

        args:

         redis-rate-limiter.burstCapacity: 20

         redis-rate-limiter.replenishRate: 5

         key-resolver: '#{@ipKeyResolver}'

     - id : ROUTER #sc-demo-alibaba-provider

      uri: lb: //sc-demo-alibaba-provider

      predicates:

       - Method=GET,POST

  #Redis配置

  redis:

   host: 192.168.3.105

   port: 6379

   #Redis连接池配置

   jedis:

    pool:

     min-idle: 0

     max-idle: 8

     max-active: 8

     max-wait: -1ms

server:

  port: 8888

feign:

  sentinel:

   enabled: true

management:

  endpoints:

   web:

    exposure:

     include: "*"

# 配置日志级别，方别调试

logging:

  level:

   org.springframework.cloud.gateway: debug