springBoot使用feign实现远程接口调用和错误熔断

1.第一步，新建两个简单的springboot项目并创建rest接口

demo系统的rest接口

plus系统的调用接口

2.在项目pom文件里导入feign和hystrix的pom依赖包

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

<!-- 支持使用feign客户端 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
        <!-- 支持使用hystrix断路器 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
        </dependency>

<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>

3.创建远程调用client及熔断回调类

package com.mybatis.plus.web.client;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;

@FeignClient(name="demo",url="${conf.address.demo}",fallbackFactory=DemoFeignClientFB.class)
public interface DemoFeignClient {
    
    @RequestMapping("cmpOclOrder/demoFeign")
    public String testFeign();

}

package com.mybatis.plus.web.client;

import feign.hystrix.FallbackFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Component;

@Component
public class DemoFeignClientFB implements FallbackFactory<DemoFeignClient> {
    private static Log logger = LogFactory.getLog(DemoFeignClientFB.class);

    @Override
    public DemoFeignClient create(Throwable throwable) {
        return new DemoFeignClient() {
            @Override
            public String testFeign() {
                return "demo系统接口调用失败";
            }
        };
    }
}