SpringCloud : 多个 @FeignClient 注解 value 设置为同一个应用的解决方案

Feign 版本10.1.0java

Spring 版本 5.1.5.RELEASEspring

SpringBoot 版本 2.1.5.RELEASEjson

SpringCloud 版本 2.1.1.RELEASE架构

在微服务架构中，当咱们须要进行服务间调用时能够选择feign组件，app

如今遇到的问题是：当同一个服务，声明多个feign实例时，启动时直接报错。微服务

解决办法，经过 Feign.builder() 手动生成代理类。ui

1.定义接口：this

public interface AbcClient{ @ResponseBody @PostMapping("/abc") JSONObject doSomething(@RequestBody Req request); } public interface DefClient{ @ResponseBody @PostMapping("/def") JSONObject doSomething(@RequestBody Req request); }

2.配置接口代理编码

import com.alibaba.fastjson.JSON; import com.alibaba.fastjson.serializer.SerializerFeature; import com.alibaba.fastjson.support.config.FastJsonConfig; import com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter; import com.alibaba.fastjson.support.springfox.SwaggerJsonSerializer; import com.netflix.appinfo.InstanceInfo; import com.netflix.discovery.EurekaClient; import com.yunplus.bpg.cloud.file.proxy.client.QcloudClient; import com.yunplus.bpg.cloud.file.proxy.client.TaskClient; import feign.Contract; import feign.Feign; import feign.codec.Decoder; import feign.codec.Encoder; import org.springframework.beans.factory.ObjectFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.autoconfigure.http.HttpMessageConverters; import org.springframework.cloud.openfeign.FeignContext; import org.springframework.cloud.openfeign.support.SpringDecoder; import org.springframework.cloud.openfeign.support.SpringEncoder; import org.springframework.http.MediaType;
import org.springframework.context.annotation.Bean; import org.springframework.stereotype.Component; import java.util.ArrayList; import java.util.List; /** * Feign配置类，负责实例化所须要的伪客户端 */ @Component public class RemoteXxxClient { public final static String SERVICE_ID = "XXX-SERVICE-ID"; /** * FeignClientFactoryBean 该工厂类中 设置builder属性时就是经过该对象，源码中可看到 */protected FeignContext feignContext; /** * 经过注入Eureka实例对象，就不用手动指定url，只须要指定服务名便可 */protected EurekaClient eurekaClient; private static final Map<String, Object> FEIGN_CLIENTS = new ConcurrentHashMap<>(); @Autowired public void init(final EurekaClient eurekaClient, final FeignContext feignContext) { this.eurekaClient = eurekaClient; this.feignContext = feignContext; } 
 @Bean public AbcClient getQcloudService() { return create(AbcClient.class, SERVICE_ID); } 
 @Bean public DefClient getTaskService() { return create(DefClient.class, SERVICE_ID); } /** * 设置编码解码器为FastJson * * @param clazz * @param serverId * @param <T> * @return
     */
    protected <T> T create(Class<T> clazz, String serverId) { InstanceInfo nextServerFromEureka = eurekaClient.getNextServerFromEureka(serverId, false); Object object = FEIGN_CLIENTS.get(nextServerFromEureka.getIPAddr()); if (Objects.isNull(object)) { object = Feign.builder() //encoder指定对象编码方式
                    .encoder(this.feignEncoder()) //decoder指定对象解码方式
                    .decoder(this.feignDecoder()) .client(feignClient) //options方法指定链接超时时长及响应超时时长
                    .options(new Request.Options(5000, 5000)) //retryer方法指定重试策略 //.retryer(new Retryer.Default(5000, 5000, 3))
                    .contract(feignContext.getInstance(serverId, Contract.class)) //target方法绑定接口与服务端地址。返回类型为绑定的接口类型。
 .target(clazz, nextServerFromEureka.getHomePageUrl()); FEIGN_CLIENTS.put(nextServerFromEureka.getIPAddr(), object); } return (T) object; } protected Encoder feignEncoder() { return new SpringEncoder(feignHttpMessageConverter()); } protected Decoder feignDecoder() { return new SpringDecoder(feignHttpMessageConverter()); } /** * 设置解码器为fastjson * * @return
     */
    private ObjectFactory<HttpMessageConverters> feignHttpMessageConverter() { final HttpMessageConverters httpMessageConverters = new HttpMessageConverters(this.getFastJsonConverter()); return () -> httpMessageConverters; } private FastJsonHttpMessageConverter getFastJsonConverter() { FastJsonHttpMessageConverter converter =
                new FastJsonHttpMessageConverter(); List<MediaType> supportedMediaTypes = new ArrayList<>(); MediaType mediaTypeJson = MediaType.valueOf(MediaType.APPLICATION_JSON_UTF8_VALUE); supportedMediaTypes.add(mediaTypeJson); converter.setSupportedMediaTypes(supportedMediaTypes); FastJsonConfig config = new FastJsonConfig(); config.getSerializeConfig().put(JSON.class, new SwaggerJsonSerializer()); config.setSerializerFeatures(SerializerFeature.DisableCircularReferenceDetect); converter.setFastJsonConfig(config); return converter; } }

3.调用url

@Slf4j @Service public class MyLogic { @Autowired private AbcClient abcClient; public void callDownstreamService() { Req req = new Req(); JSONObject rsp = abcClient.doSomething(req); } }

PS:

feign 同一个服务编写多个远程调用实例解决办法

@FeignClient同一个name使用多个配置类的解决方案