Spring Cloud（十）Hystrix实战

矫情吗；* 2022-12-16 09:27 159阅读 0赞

## 前期准备 ##

1、创建一个Eureka Server工程，项目名称：eureka-server

2、创建一个Eureka Client 服务提供者 工程，项目名称：eureka-client1

工程eureka-server和eureka-client1 创建请参考

[Spring Cloud（三）Eureka实战][Spring Cloud_Eureka]

## 1、启动Eureka 服务提供者、Eureka注册中心 ##

启动`eureka-server、eureka-client1`

PS：eureka-client1 在idea中通过多实例启动

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTE0ODM3_size_16_color_FFFFFF_t_70_pic_center]

查看 Eureka 控制台

![在这里插入图片描述][20201018212436642.png_pic_center]

## 2、创建并启动服务消费者 ##

项目名称：service-hystrix

<?xml version="1.0" encoding="UTF-8"?>
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
    
        <groupId>com.yi</groupId>
        <artifactId>serice-hystrix</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <name>serice-hystrix</name>
        <description>serice-hystrix</description>
    
        <parent>
            <groupId>com.yi</groupId>
            <artifactId>finchley</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </parent>
    
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
            </dependency>
        </dependencies>
    
    </project>

eureka:
      client:
        serviceUrl:
          defaultZone: http://localhost:8761/eureka/
    server:
      port: 8764
    spring:
      application:
        name: service-hystrix

@EnableHystrix
    @SpringBootApplication
    @EnableEurekaClient
    @EnableDiscoveryClient
    public class ServiceRibbonApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(ServiceRibbonApplication.class, args);
        }
    
        @Bean
        @LoadBalanced
        RestTemplate restTemplate() {
            return new RestTemplate();
        }
    }

> @EnableHystrix注解开启Hystrix

@Service
    public class HelloService {
    
        @Autowired
        RestTemplate restTemplate;
    
        @HystrixCommand(fallbackMethod = "helloHystrix")
        public String helloService(String name) {
            return restTemplate.getForObject("http://SERVICE-CLIENT/hello?name=" + name, String.class);
        }
    
        public String helloHystrix(String name) {
            return "hello :"+name+",服务繁忙，稍后再试!";
        }
    }

> @HystrixCommand ：提供熔断器的功能，并指定了fallbackMethod熔断方法

@RestController
    public class HelloControler {
    
        @Autowired
        HelloService helloService;
    
        @GetMapping(value = "/hello")
        public String hello(@RequestParam String name) {
            return helloService.helloService(name);
        }
    }

访问：`http://localhost:876/hello?name=yi`

1、如果`service-client` 服务正常启动，

轮询出现，与前章节ribbon一致

hello yi ，port is 8762
    hello yi ，port is 8763

2、如果`service-client` 服务关闭，出现

hello : yi，服务繁忙，稍后再试!

## 3、Feign结合使用Hystrix ##

Feign整合了Hystrix，具有熔断的能力。

[Spring Cloud（八）Feign实战（hystrix断路器）][Spring Cloud_Feign_hystrix]

--------------------

git项目源码：[https://github.com/yilei111/-Spring-Cloud-Finchley][https_github.com_yilei111_-Spring-Cloud-Finchley]

[Spring Cloud_Eureka]: https://blog.csdn.net/qq_29914837/article/details/109085405
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzI5OTE0ODM3_size_16_color_FFFFFF_t_70_pic_center]: /images/20221123/dcd5d949ef464fd9a181c950d74aa2af.png
[20201018212436642.png_pic_center]: /images/20221123/0e46996f9aa04eb685fb2e24fff1cfd5.png
[Spring Cloud_Feign_hystrix]: https://blog.csdn.net/qq_29914837/article/details/109171563
[https_github.com_yilei111_-Spring-Cloud-Finchley]: https://github.com/yilei111/-Spring-Cloud-Finchley