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关于springcloud中使用feign出现LinkedHashMap can not be cast to xxx 的解决方案
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- 博主遇到这个问题也很久了,在网上也看了没找到解决方案,一直没时间去解决,最近稍微抽了一点时间研究了一下,分享出来造福众多的码农朋友,feign默认是根据返回的数据解析为LinkedHashMap这种key value的格式,但是我们项目中一般会有自定义的Result<T,E>这样的复杂类型的对象,这样的话,feign就不能像dubbo这样的rpc那样得到我们自己想要的Result<T,E>对象,下面是解决方案:
解决方案 自定义FeignClient,覆盖提供的FeignClient
@Configuration
public class FeignConfig {
@Bean
public Decoder feignDecoder() {
HttpMessageConverter jacksonConverter = new MappingJackson2HttpMessageConverter(objectMapper());
ObjectFactory<HttpMessageConverters> objectFactory = () -> new HttpMessageConverters(jacksonConverter);
return new ResponseEntityDecoder(new SpringDecoder(objectFactory));
}
@Bean
public Encoder feignEncoder(){
HttpMessageConverter jacksonConverter = new MappingJackson2HttpMessageConverter(objectMapper());
ObjectFactory<HttpMessageConverters> objectFactory = () -> new HttpMessageConverters(jacksonConverter);
return new SpringEncoder(objectFactory);
}
public ObjectMapper objectMapper(){
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT, true);
return objectMapper;
}
}
- 再附上一段调用的代码 ,需要注意的是在接口上必须加上你需要转化的结果,不然还是 LinkedHashMap
@FeignClient(value = "xxx-service",fallback = UserFacadeFallback.class)
@Component
public interface UserFacade {
@RequestMapping(value = "/user", method = {RequestMethod.POST})
UserResponse<EnumGeneralResultCode,UserDto> getUserDto(@RequestBody UserDto user);
}
最后
开始愉快的撸码吧 !