谷粒商城笔记+踩坑（25）——整合Sentinel实现流控和熔断降级

<dependency>
    <groupId>com.alibaba.cloudgroupId>
    <artifactId>spring-cloud-starter-alibaba-sentinelartifactId>
dependency>
<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-actuatorartifactId>
dependency>

hgw@HGWdeAir SpringCloudSentinel# java -jar sentinel-dashboard-1.6.3.jar --server.port=8333

#sentinel控制台地址
spring.cloud.sentinel.transport.dashboard=127.0.0.1:8333
#sentinel传输端口
spring.cloud.sentinel.transport.port=8713
#Spring Boot声明哪些端点是可公开的，即暴露给外部访问的。
#默认情况下会将所有端点都暴露出去，包括health、info等常用端点，这在生产环境中可能会存在一定的安全隐患。
#一般暴露health,info就行了
management.endpoints.web.exposure.include=*

package com.atguigu.gulimall.seckill.config;
/**
 * Description: Sentinel-自定义流控响应
 */
@Configuration
public class SeckillSentinelConfig {
    public SeckillSentinelConfig() {
        WebCallbackManager.setUrlBlockHandler(new UrlBlockHandler() {
            @Override
            public void blocked(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws IOException {
                R error = R.error(BizCodeEnume.TO_MANY_REQUEST.getCode(), BizCodeEnume.TO_MANY_REQUEST.getMsg());
                httpServletResponse.setCharacterEncoding("UTF-8");
                httpServletResponse.setContentType("application/json");
                httpServletResponse.getWriter().write(JSON.toJSONString(error));
            }
        });
    }
}

<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-actuatorartifactId>
dependency>

#sentinel控制台地址
spring.cloud.sentinel.transport.dashboard=127.0.0.1:8333
management.endpoints.web.exposure.include=*

#sentinel是不会对feign进行监控的，需要开启配置
feign.sentinel.enabled=true

#sentinel是不会对feign进行监控的，需要开启配置
feign.sentinel.enabled=true

package com.atguigu.gulimall.product.feign.fallback;
 
@Slf4j
@Component
public class SeckillFeignServiceFallBack implements SeckillFeignService {
    @Override
    public R getSkuSeckillInfo(Long skuId) {
        log.error("熔断方法调用...getSkuSeckillInfo");
        return R.error(BizCodeEnume.TO_MANY_REQUEST.getCode(),BizCodeEnume.TO_MANY_REQUEST.getMsg());
    }
}

package com.atguigu.gulimall.product.feign;
 
@FeignClient(value = "gulimall-seckill", fallback = SeckillFeignServiceFallBack.class)
public interface SeckillFeignService {
    @GetMapping("/sku/seckill/{skuId}")
    R getSkuSeckillInfo(@PathVariable("skuId") Long skuId);
}

     try(Entry entity = SphU.entry("自定义受保护资源名")) {
      // 业务逻辑
      } catch (BlockException e) {
         //一定要配置被限流以后的默认返回
      }

try(Entry entity = SphU.entry("自定义受保护资源名")) {
	  // 业务逻辑
} catch (BlockException e) {
  	//一定要配置被限流以后的默认返回
}

/**
 * 获取当前参与秒杀的商品
 *
 * @return
 */
@Override
public List getCurrentSeckillSkus() {
    try(Entry entity = SphU.entry("seckillSkus")) {
        // 1、确定当前时间属于哪个秒杀场次
        long time = new Date().getTime();
        Set keys = redisTemplate.keys(SESSION_CACHE_PREFIX + "*");
        for (String key : keys) {
            // seckill:sessions:1650153600000_1650160800000
            String replace = key.replace(SESSION_CACHE_PREFIX, "");
            String[] s = replace.split("_");
            long start = Long.parseLong(s[0]);
            long end = Long.parseLong(s[1]);
            if (time >= start && time <= end) {
                // 2、获取指定秒杀场次需要的所有商品信息
                List range = redisTemplate.opsForList().range(key, -100, 100);
                BoundHashOperations hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
                List list = hashOps.multiGet(range);
                if (list != null) {
                    List collect = list.stream().map(item -> {
                        SecKillSkuRedisTo redis = JSON.parseObject((String) item, SecKillSkuRedisTo.class);
                        redis.setRandomCode(null);  // 当前秒杀开始了需要随机码
                        return redis;
                    }).collect(Collectors.toList());
                    return collect;
                }
                break;
            }
        }
    } catch (BlockException e) {
        log.error("资源被限流{}"+e.getMessage());
    }
    return null;
}

 @SentinelResource(value = "getCurrentSeckillSkusResource",blockHandler = "blockHandler",fallback = "fallback")

/**
 * getCurrentSeckillSkus()方法被限流/降级/系统保护的时候调用
 * @return
 */
public List blockHandler(BlockException e){
    log.error("getCurrentSeckillSkus()方法被限流/降级/系统保护");
    return null;
}
/**
 * 获取当前参与秒杀的商品
 * blockHandler 函数会在原方法被限流/降级/系统保护的时候调用
 * fallback 会针对所有类型的异常
 * @return
 */
@SentinelResource(value = "getCurrentSeckillSkusResource",blockHandler = "blockHandler")
@Override
public List getCurrentSeckillSkus() {
    try(Entry entity = SphU.entry("seckillSkus")) {
        // 1、确定当前时间属于哪个秒杀场次
        long time = new Date().getTime();
        Set keys = redisTemplate.keys(SESSION_CACHE_PREFIX + "*");
        for (String key : keys) {
            // seckill:sessions:1650153600000_1650160800000
            String replace = key.replace(SESSION_CACHE_PREFIX, "");
            String[] s = replace.split("_");
            long start = Long.parseLong(s[0]);
            long end = Long.parseLong(s[1]);
            if (time >= start && time <= end) {
                // 2、获取指定秒杀场次需要的所有商品信息
                List range = redisTemplate.opsForList().range(key, -100, 100);
                BoundHashOperations hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
                List list = hashOps.multiGet(range);
                if (list != null) {
                    List collect = list.stream().map(item -> {
                        SecKillSkuRedisTo redis = JSON.parseObject((String) item, SecKillSkuRedisTo.class);
                        redis.setRandomCode(null);  // 当前秒杀开始了需要随机码
                        return redis;
                    }).collect(Collectors.toList());
                    return collect;
                }
                break;
            }
        }
    } catch (BlockException e) {
        log.error("资源被限流{}"+e.getMessage());
    }
    return null;
}

<dependency>
    <groupId>com.alibaba.cloudgroupId>
    <artifactId>spring-cloud-alibaba-sentinel-gatewayartifactId>
    <version>2.1.0.RELEASEversion>
dependency>

package com.atguigu.gulimall.gateway.config;
@Configuration
public class SentinelGatewayConfig {
    public SentinelGatewayConfig() {
        GatewayCallbackManager.setBlockHandler(new BlockRequestHandler() {
           // 网关限制了请求，就会调用此回调 Mono Flux
            @Override
            public Mono handleRequest(ServerWebExchange serverWebExchange, Throwable throwable) {
                R error = R.error(BizCodeEnume.TO_MANY_REQUEST.getCode(), BizCodeEnume.TO_MANY_REQUEST.getMsg());
                String errJson = JSON.toJSONString(error);
 
                Mono body = ServerResponse.ok().body(Mono.just(errJson), String.class);
                return body;
            }
        });
    }
}