SpringCloud--Feign

Feign主要用于服务之间的互相调用，内部集成了Robbin负载均衡以及Hystrix熔断
导入依赖

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

Feign的客户端
首先开启Hystrix

feign:
hystrix:
enabled: true # 开启Feign的熔断功能

首先，我们要定义一个类，实现刚才编写的UserFeignClient，作为fallback的处理类

@Component
public class UserFeignClientFallback implements UserFeignClient {
@Override
public User queryUserById(Long id) {
User user = new User();
user.setId(id);
user.setName("用户查询出现异常！");
return user;
}
}

然后在UserFeignClient中，指定刚才编写的实现类

@FeignClient(value = "user-service", fallback = UserFeignClientFallback.class)
public interface UserFeignClient {

@GetMapping("/user/{id}")
User queryUserById(@PathVariable("id") Long id);
}

启动类

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