SpringCloud Alibaba Sentinel 对feign 的支持

1.开启支持

# 打开 Sentinel 对 Feign 的支持
feign:
  sentinel:
    enabled: true

2.pom添加

<!-- Sentinel 适配了 Feign, 可以实现服务间调用的保护 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

3.添加feign支持

/**
 * <h1>Sentinel 集成到 SpringCloud 工程中</h1>
 * */
@EnableFeignClients
@EnableDiscoveryClient
@SpringBootApplication
public class SentinelClientApplication {

    public static void main(String[] args) {

        SpringApplication.run(SentinelClientApplication.class, args);
    }
}

4.feign调用

/**
 * <h1>通过 Sentinel 对 OpenFeign 实现熔断降级</h1>
 * */
@FeignClient(
        value = "e-commerce-imooc",
        fallback = SentinelFeignClientFallback.class
)
public interface SentinelFeignClient {

    @RequestMapping(value = "qinyi", method = RequestMethod.GET)
    CommonResponse<String> getResultByFeign(@RequestParam Integer code);
}

/**
 * <h1>Sentinel 对 OpenFeign 接口的降级策略</h1>
 * */
@Slf4j
@Component
public class SentinelFeignClientFallback implements SentinelFeignClient {

    @Override
    public CommonResponse<String> getResultByFeign(Integer code) {

        log.error("request supply for test has some error: [{}]", code);
        return new CommonResponse<>(
                -1,
                "sentinel feign fallback",
                "input code: "+ code
        );
    }
}

/**
 * <h1>OpenFeign 集成 Sentinel 实现熔断降级</h1>
 * */
@Slf4j
@RestController
@RequestMapping("/sentinel-feign")
public class SentinelFeignController {

    private final SentinelFeignClient sentinelFeignClient;

    public SentinelFeignController(SentinelFeignClient sentinelFeignClient) {
        this.sentinelFeignClient = sentinelFeignClient;
    }

    /**
     * <h2>通过 Feign 接口去获取结果</h2>
     * */
    @GetMapping("/result-by-feign")
    public CommonResponse<String> getResultByFeign(@RequestParam Integer code) {
        log.info("coming in get result by feign: [{}]", code);
        return sentinelFeignClient.getResultByFeign(code);
    }
}