feign.hystrix.enabled=true

@Component
public class GradeClientImpl implements GradeClient {

    @Override
    public List<Grade> findAll() {
    	//可以：
        //打印日志
        //使用消息隊(duì)列發(fā)送消息
        //發(fā)送短信

        //測(cè)試用
        List<Grade> list = new ArrayList<Grade>();
        Grade grade = new Grade();
        grade.setGradeId(404);
        grade.setGradeName("進(jìn)入了熔斷器");
        list.add(grade);
        return list;
    }
}

@FeignClient(name="eureka-grade",fallback = GradeClientImpl.class)
public interface GradeClient {

    @GetMapping(value = "/grades")
    List<Grade> findAll();
}

<dependency>
	<groupId>org.springframework.cloud</groupId>
	<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
</dependency>

@EnableHystrix

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
@EnableHystrix
public class EurekaStudentApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaStudentApplication.class, args);
    }

}

@RestController
public class StudentController {

    @Autowired
    private StudentService studentService;

    @Autowired
    private GradeClient gradeClient;

    @GetMapping(value = "/grades")
    //一旦出錯(cuò)則執(zhí)行Grades方法
    @HystrixCommand(fallbackMethod = "Grades")
    public List<Grade> findAll1(){
        return gradeClient.findAll();
    }
	
	//出錯(cuò)執(zhí)行的方法
    public List<Grade> Grades() {
        //可以：
        //打印日志
        //使用消息隊(duì)列發(fā)送消息
        //發(fā)送短信

        //測(cè)試
        List<Grade> list = new ArrayList<>();
        Grade grade = new Grade();
        grade.setGradeId(0);
        grade.setGradeName("出錯(cuò)了,執(zhí)行了熔斷器");
        list.add(grade);
        return list;
    }


    @GetMapping(value = "/students")
    public List<Student> findAll(){
        return studentService.findAll();
    }
}