基于注解的Sentinel限流熔断

依赖

<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-annotation-aspectj</artifactId>
    <version>1.8.8</version>
    <exclusions>
        <exclusion>
            <groupId>com.alibaba.csp</groupId>
            <artifactId>sentinel-core</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>com.alibaba.csp</groupId>
    <artifactId>sentinel-core</artifactId>
    <version>1.8.8</version>
</dependency>

配置

全局配置

@Configuration
public class SentinelAspectConfiguration {
    @Bean
    public SentinelResourceAspect sentinelResourceAspect() {
        return new SentinelResourceAspect();
    }
}

注入限流熔断规则

@Component
public class SentinelConfig {

    /* 只需要在nacos中配置flowRule，也可以根据nacos配置动态刷新配置，看情况 */
    @PostConstruct
    public void initFlowRules() {
        List<FlowRule> flowRules = new ArrayList<>();

        FlowRule rule = new FlowRule();
        rule.setResource(SentinelResourceConstant.TEST_API); // 资源名要与 @SentinelResource 的 value 一致
        rule.setGrade(RuleConstant.FLOW_GRADE_QPS);
        rule.setCount(1); // QPS 限流阈值

        FlowRule rul2 = new FlowRule();
        rul2.setResource(SentinelResourceConstant.HELLO_API); // 资源名要与 @SentinelResource 的 value 一致
        rul2.setGrade(RuleConstant.FLOW_GRADE_QPS);
        rul2.setCount(2); // QPS 限流阈值

        flowRules.add(rule);
        flowRules.add(rul2);
        FlowRuleManager.loadRules(flowRules);
    }
}

服务

@Service
@Slf4j
public class TestService {

    @Resource
    private HelloClient helloClient;

    @SentinelResource(value = SentinelResourceConstant.TEST_API, blockHandler = "blockHandler", blockHandlerClass = ExceptionUtil.class)
    public String chain(String pa) {
        return pa + "OKK";
    }

    @SentinelResource(value = SentinelResourceConstant.HELLO_API, blockHandler = "blockHandlerForHello", blockHandlerClass = ExceptionUtil.class)
    public String hello() {
        return helloClient.hello();
    }
}

异常

@Slf4j
public class ExceptionUtil {

    public static String blockHandler(String pa, BlockException ex) {
        log.error("限流：{}", String.valueOf(ex));
        return "限流";
    }

    public static String blockHandlerForHello(BlockException ex) {
        log.error("限流：{}", String.valueOf(ex));
        return "限流";
    }
}

注意事项

• SentinelResource注解中的value必须和SentinelConfig 中rule的resource保持完全一致
• FlowRule的具体限流指标有多种，可以参考官方文档选择