springcloud之Hystrix初识篇—结合ResTeamplate使用简例

喜欢ヅ旅行 2023-07-18 14:04 44阅读 0赞

1、添加pom依赖。

<dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
       <version>2.2.1.RELEASE</version>
    </dependency>

2、coding

启动项添加配置

@SpringBootApplication
    @EnableHystrix
    public class TestDemoApplication {
        public static void main(String[] args) {
            SpringApplication.run(TestDemoApplication.class, args);
        }
    }

编写service实例

public interface HystrixRestTemplateService {
    
        String hystrixRestTemplateSend(String body);
    }

import com.example.springcloud.testdemo.exception.HystrixIgnoreException;
    import com.example.springcloud.testdemo.service.HystrixRestTemplateService;
    import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
    import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    import org.springframework.web.client.RestTemplate;
    
    /**
     * Created by py
     * 2020/3/24
     */
    @Service
    public class HystrixRestTemplateServiceImpl implements HystrixRestTemplateService {
        private Logger logger = LoggerFactory.getLogger(this.getClass());
    
        @Autowired
        private RestTemplate restTemplate;
    
        @Override
        //fallbackMethod:请求异常执行备用逻辑(降级)的方法名称
        @HystrixCommand(fallbackMethod="sendFail")
        public String hystrixRestTemplateSend(String body) {
            String url = "http://test1/eureka-clinet1/hystrixRestTemplate/Code";
            ResponseEntity<String> result = restTemplate.postForEntity(url,body,String.class);
            return "test";
        }
        /**
         *  降级方法：调用方法异常则执行此方法
         *  PS:请求参数和返回类型要和使用该降级方法的方法保持一致
         */
        public String sendFail(String body){
            /*备用逻辑：
              body ：hystrixRestTemplateSend方法请求的参数  
              这块我们可以组装参数告知客户端异常，或基于自己业务需求做其他处理
            */
            return "restTemplate熔断："+body;
        }
    }

创建controller

import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestBody;
    import org.springframework.web.bind.annotation.RestController;
    
    /**
     * Created by py
     * 2020/3/24
     */
    @RestController
    public class HystrixTestController {
    
        @Autowired
        private HystrixRestTemplateService hystrixRestTemplateService;
    
        @PostMapping("/hystrixRestTemplate/Send")
        public String hystrixSend(@RequestBody String body){
    
            String result = hystrixRestTemplateService.hystrixRestTemplateSend(body);
    
            return result;
        }
    }

正常请求：

![2020032820381118.png][]

停用服务提供者：

![20200328203929581.png][]

[2020032820381118.png]: /images/20230528/b2d73faae89341ac8ec3ff5145834628.png
[20200328203929581.png]: /images/20230528/751543e3f8c64fbf8c5de8eccb14c55a.png