SpringCloud-基于feign自带熔断器实现熔断

一、maven配置

 <groupId>com.wk.sc</groupId>
    <artifactId>springcloud-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
    </properties>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.4.RELEASE</version>
        <relativePath/>
    </parent>

    <dependencies>
         <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

二、application.yml配置

server:
  port: 7071

eureka:
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka
spring:
  application:
    name: service-feign
feign:
  hystrix:
    enabled: true  # feign自带熔断器，默认是关闭的，需要手动开启

三、启动类

@SpringBootApplication
@EnableDiscoveryClient
@EnableEurekaClient
@EnableFeignClients
public class ServiceFeignApplication {

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

}

四、服务调用

• 接口定义

/**
 * feign服务调用示例
 *
 */
@FeignClient(value = "service-hi",fallback = HelloServiceImpl.class)  //配置feign自带熔断器，fallback指定熔断后调用方法
public interface IHelloService {
    /**
     * 调用服务
     *
     * @param name
     * @return
     */
    @RequestMapping(value = "/hi", method = RequestMethod.GET)
    String sayHi(@RequestParam("name") String name);
}

• 接口实现

/**
 * Feign 熔断服务实现
 *
 */
@Component
public class HelloServiceImpl implements IHelloService {
    @Override
    public String sayHi(String name) {
        return "sorry  " + name;
    }
}

五、控制器调用服务

/**
 * feign远程调用
 *
 */
@RestController
public class HiController {

    @Autowired
    private IHelloService helloService;

    @GetMapping(value = "/hi")
    public String sayHi(@RequestParam String name) {
        return helloService.sayHi(name);
    }

}