记录一个Fegin的Bug

 HttpResult httpResult = ssoAuthControllerFeign.checkToken(tokens.get(0));

代码走到了这这里，进行Fegin调用的时候报了异常；
大致的报错内容为
feign.codec.DecodeException: No qualifying bean of type 'org.springframework.boot.autoconfigure.http.HttpMessageConverters' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)} at feign.AsyncResponseHandler.decode(AsyncResponseHandler.java:119) ~[feign-core-10.10.1.jar:na] Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: Error has been observed at the following site(s): |_ checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain] |_ checkpoint ⇢ org.springframework.boot.actuate.metrics.web.reactive.server.MetricsWebFilter [DefaultWebFilterChain] |_ checkpoint ⇢ HTTP GET "/java/sayHi" [ExceptionHandlingWebHandler]

Spring没有加载这个bean导致的；
出现这个问题的原因是Gateway并没有SpringMvc那一套系统，使用的是webflux的方式，所以并没有这个转换器；
[突然想起了之前引入gateway依赖的时候提示我spring-boot-web冲突让我把那个删掉，原来这就是后手阿]

所以我们只需要手动把这个bean引入就可以了
可以在启动类下面。也可以另起一个配置类，手动的将这个bean注入到容器中，问题就解决了

@Configuration
public class Config {
    @Bean
    @ConditionalOnMissingBean
    public HttpMessageConverters messageConverters(ObjectProvider> converters) {
        return new HttpMessageConverters(converters.orderedStream().collect(Collectors.toList()));
    }
}