Springcloud 集成 Feign

心已赠人 2023-10-01 08:25 13阅读 0赞

Feign 整合了 Ribbon 与 Hystrix，同时还提供了一种声明式的 Webservice 客户端定义的方式。

## 1.nacos 注册中心 ##

[参考：Springcloud 集成 Nacos注册中心][Springcloud _ Nacos]

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## **2.Provider 服务提供者** ##

参考[：Springcloud 集成 Nacos简单服务调用][Springcloud _ Nacos 1]

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## **3.Consumer 消费者** ##

### 3.1pom.xml ###

<dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
                <version>2.2.2.RELEASE</version>
            </dependency>

### 3.2启动类 ###

package com.lhy.cloud;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    // 开启Feign
    @EnableFeignClients
    @SpringBootApplication
    @EnableDiscoveryClient
    public class CloudApiApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(CloudApiApplication.class, args);
        }
    }

### 3.3本地Feign客户端 ###

package com.lhy.cloud.client;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    
    
    @FeignClient(name = "user-api", path = "/user")
    public interface UserClient {
    
        @GetMapping("/headPortrait")
        String headPortrait();
    
    }

### 3.4测试类 ###

package com.lhy.cloud.controller;
    
    import com.lhy.cloud.client.UserClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import javax.annotation.Resource;
    
    /**
     * Class description.
     *
     * @author ocean liu
     * @createTime 2021/11/29 - 10:57
     */
    @RequestMapping("/cloud")
    @RestController
    public class CloudController {
    
        @Resource
        private UserClient userClient;
    
        @RequestMapping("/user/headPortrait")
        public String getUserHeadPortrait() {
            return userClient.headPortrait();
        }
    }

### 3.5验证 ###

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAT2NlYW5A5LiK5rqQ56CB_size_20_color_FFFFFF_t_70_g_se_x_16][]

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## **4.负载均衡配置** ##

pom.xml 配置负载策略

user-api:
      ribbon:
        # com.netflix.loadbalancer.RoundRobinRule           默认 轮询
        # com.netflix.loadbalancer.RandomRule               随机
        # com.netflix.loadbalancer.BestAvailableRule        最小并发
        # com.netflix.loadbalancer.WeightedResponseTimeRule 响应时间 权重
        # com.netflix.loadbalancer.ZoneAvoidanceRule        复合判读 区域性能也服务可用性
        # com.netflix.loadbalancer.RetryRule                失败重试
        NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RoundRobinRule

## **5.熔断配置** ##

pom.xml 开启熔断器

feign:
      hystrix:
        enabled: true

重新编写本地Feign客户端，配置fallback

package com.lhy.cloud.client;
    
    import com.lhy.cloud.client.fallback.UserClientFallback;
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.GetMapping;
    
    
    @FeignClient(name = "user-api", path = "/user", fallback = UserClientFallback.class)
    public interface UserClient {
    
        @GetMapping("/headPortrait")
        String headPortrait();
    
    }

编写fallback处理类

package com.lhy.cloud.client.fallback;
    
    import com.lhy.cloud.client.UserClient;
    import org.springframework.stereotype.Component;
    
    /**
     * Class description.
     *
     * @author ocean liu
     * @createTime 2021/12/9 - 9:54
     */
    @Component
    public class UserClientFallback implements UserClient {
    
        @Override
        public String headPortrait() {
            return "default.png";
        }
    }

测试关闭provider服务

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAT2NlYW5A5LiK5rqQ56CB_size_20_color_FFFFFF_t_70_g_se_x_16 1][]

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAT2NlYW5A5LiK5rqQ56CB_size_20_color_FFFFFF_t_70_g_se_x_16 2][]

测试开启provider服务

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAT2NlYW5A5LiK5rqQ56CB_size_20_color_FFFFFF_t_70_g_se_x_16 3][]

![watermark_type_d3F5LXplbmhlaQ_shadow_50_text_Q1NETiBAT2NlYW5A5LiK5rqQ56CB_size_20_color_FFFFFF_t_70_g_se_x_16 4][]

[Springcloud _ Nacos]: https://blog.csdn.net/qq_34253002/article/details/121608128?spm=1001.2014.3001.5501
[Springcloud _ Nacos 1]: https://blog.csdn.net/qq_34253002/article/details/121614212?spm=1001.2014.3001.5501
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