《Seckill秒杀系统》第88章：业务网关整合Sentinel流控

@Configuration
@ComponentScan(value = {"io.binghe.seckill", "com.alibaba.cola"})
@ServletComponentScan(basePackages = {"io.binghe.seckill"})
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class SeckillGatewayConfig {
    private final List<ViewResolver> viewResolvers;

    private final ServerCodecConfigurer serverCodecConfigurer;

    @Value("${spring.cloud.gateway.discovery.locator.route-id-prefix}")
    private String routeIdPrefix;

    public SeckillGatewayConfig(ObjectProvider<List<ViewResolver>> viewResolversProvider,
                                ServerCodecConfigurer serverCodecConfigurer) {
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }
    /**
     * 初始化一个限流的过滤器
     */
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public GlobalFilter sentinelGatewayFilter() {
        return new SentinelGatewayFilter();
    }
    @PostConstruct
    public void init() {
        this.initGatewayRules();
        this.initBlockHandlers();
    }
    /**
     * 配置初始化的限流参数
     */
    private void initGatewayRules() {
        Set<GatewayFlowRule> rules = new HashSet<>();
        //用户微服务
        rules.add(this.getGatewayFlowRule(getResource("seckill-user")));
        //秒杀活动微服务
        rules.add(this.getGatewayFlowRule(getResource("seckill-activity")));
        //秒杀商品微服务
        rules.add(this.getGatewayFlowRule(getResource("seckill-goods")));
        //秒杀订单微服务
        rules.add(this.getGatewayFlowRule(getResource("seckill-order")));
        //库存微服务
        rules.add(this.getGatewayFlowRule(getResource("seckill-stock")));
        //预约微服务
        rules.add(this.getGatewayFlowRule(getResource("seckill-reservation")));
        //加载规则
        GatewayRuleManager.loadRules(rules);
    }

    private String getResource(String targetServiceName){
        if (routeIdPrefix == null){
            routeIdPrefix = "";
        }
        return routeIdPrefix.concat(targetServiceName);
    }

    private GatewayFlowRule getGatewayFlowRule(String resource){
        //传入资源名称生成GatewayFlowRule
        GatewayFlowRule gatewayFlowRule = new GatewayFlowRule(resource);
        //限流阈值
        gatewayFlowRule.setCount(1);
        //统计的时间窗口，单位为
        gatewayFlowRule.setIntervalSec(1);
        return gatewayFlowRule;
    }

    /**
     * 配置限流的异常处理器
     */
    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public SentinelGatewayBlockExceptionHandler sentinelGatewayBlockExceptionHandler() {
        return new SentinelGatewayBlockExceptionHandler(viewResolvers, serverCodecConfigurer);
    }
    /**
     * 自定义限流异常页面
     */
    private void initBlockHandlers() {
        BlockRequestHandler blockRequestHandler = (serverWebExchange, throwable)-> {
            Map<String, Object> map = new HashMap<>();
            map.put("code", 1001);
            map.put("codeMsg", "Sentinel-接口被限流了");
            return ServerResponse.status(HttpStatus.OK).
                    contentType(MediaType.APPLICATION_JSON_UTF8).
                    body(BodyInserters.fromObject(map));
        };
        GatewayCallbackManager.setBlockHandler(blockRequestHandler);
    }
}