springcloud学习笔记(七)Feign与Hystrix的结合使用 Hystrix(2)

悠悠 2022-05-31 00:09 223阅读 0赞

首先引入依赖：

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <parent>
            <artifactId>SpringCloudTest</artifactId>
            <groupId>com.xc.springcloud</groupId>
            <version>1.0-SNAPSHOT</version>
        </parent>
        <modelVersion>4.0.0</modelVersion>
    
        <artifactId>EurekaService_feign_hystrix</artifactId>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-actuator</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-feign</artifactId>
            </dependency>
    
    
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-hystrix</artifactId>
            </dependency>
    
        </dependencies>
    
    
    </project>

然后启动类加入feign和Hystrix注解，完整代码如下：

package com.xc;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.feign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableFeignClients
    @EnableCircuitBreaker
    public class Feign_hystrixAPP {
        public static  void main(String args[]){
            SpringApplication.run(Feign_hystrixAPP.class,args);
        }
    }

写一个feign客户端

package com.xc.service;
    
    import com.xc.entity.User;
    import org.springframework.cloud.netflix.feign.FeignClient;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    
    @FeignClient(name="cloud-test")
    public interface FeignService {
    
        @RequestMapping(value = "/say/{words}",method = RequestMethod.GET)
        public String sayHello(@PathVariable("words") String words);
    }

feign与Hystrix结合使用十分简单，只需要给feign写一个实现类  然后在feign客户端 填写回调地址:

实现类如下：

package com.xc.service;
    
    import org.springframework.stereotype.Component;
    
    @Component
    public class TestFallBack implements  FeignService{
    
        @Override
        public String sayHello(String words) {
            return "TestFallBack";
        }
    }

@component注解不加  启动会报错

然后feign客户端：

package com.xc.service;
    
    import com.xc.entity.User;
    import org.springframework.cloud.netflix.feign.FeignClient;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    
    @FeignClient(name="cloud-test",fallback = TestFallBack.class)
    public interface FeignService {
    
        @RequestMapping(value = "/say/{words}",method = RequestMethod.GET)
        public String sayHello(@PathVariable("words") String words);
    }

写一个Rest服务：

package com.xc.controller;
    
    import com.xc.entity.User;
    import com.xc.service.FeignService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class FeignHystrixController {
    
        @Autowired
        private FeignService feignService;
    
        @RequestMapping(value="/getuser/{words}",method = RequestMethod.GET)
        public String getUser(@PathVariable("words")String words){
            return feignService.sayHello(words);
        }
    }

OK，测试代码已经写好，开始测试：

1，访问接口：http://localhost:7778/getuser/haha

![SouthEast][]

返回正常。

2.现在我们断掉cloud-test微服务，再访问：http://localhost:7778/getuser/haha

![SouthEast 1][]

成功跳到失败回调方法。。测试完成！

[SouthEast]: /images/20220531/ec4e1f06a48e41338d4dfedd1b854ab6.png
[SouthEast 1]: /images/20220531/77ab0058f0734d2e83ab2b8ee8c93658.png