Feign实现微服务间文件传递

加入依赖

<dependency>
   <groupId>io.github.openfeign.form</groupId>
   <artifactId>feign-form-spring</artifactId>
   <version>3.3.0</version>
</dependency>

@FeignClient(name="attachment-service",  configuration = {AttachmentFeignClient.MultipartSupportConfig.class}
 fallback=AttachmentHystrixFallback.class)
public interface AttachmentFeignClient {

@RequestMapping(value= {"upload"}, consumes = {"multipart/form-data"})
void upload(@RequestPart(name="file") MultipartFile file, @RequestParam(name="attachableId") Long attachableId, 
        @RequestParam(name="className") String className, @RequestParam(name="appName") String appName);

 public class MultipartSupportConfig {
    @Bean
    @Primary
    @Scope("prototype")
    public Encoder feignFormEncoder() {
        return new SpringFormEncoder();
    }
  }
}

如果你想要一次上传多个文件比如MultipartFile[]，那么你需要扩展SpringFormEncoder

import feign.RequestTemplate;
import feign.codec.EncodeException;
import feign.codec.Encoder;
import feign.form.ContentType;
import feign.form.FormEncoder;
import feign.form.MultipartFormContentProcessor;
import feign.form.spring.SpringManyMultipartFilesWriter;
import feign.form.spring.SpringSingleMultipartFileWriter;
import org.springframework.web.multipart.MultipartFile;

import java.lang.reflect.Type;
import java.util.Collections;
import java.util.Map;

public class FeignSpringFormEncoder extends FormEncoder {


    /**
     * Constructor with the default Feign's encoder as a delegate.
     */
    public FeignSpringFormEncoder() {
        this(new Default());
    }


    /**
     * Constructor with specified delegate encoder.
     *
     * @param delegate delegate encoder, if this encoder couldn't encode object.
     */
    public FeignSpringFormEncoder(Encoder delegate) {
        super(delegate);

        MultipartFormContentProcessor processor = (MultipartFormContentProcessor) getContentProcessor(ContentType.MULTIPART);
        processor.addFirstWriter(new SpringSingleMultipartFileWriter());
        processor.addFirstWriter(new SpringManyMultipartFilesWriter());
    }


    @Override
    public void encode(Object object, Type bodyType, RequestTemplate template) throws EncodeException {
        if (bodyType.equals(MultipartFile.class)) {
            MultipartFile file = (MultipartFile) object;
            Map data = Collections.singletonMap(file.getName(), object);
            super.encode(data, MAP_STRING_WILDCARD, template);
            return;
        } else if (bodyType.equals(MultipartFile[].class)) {
            MultipartFile[] file = (MultipartFile[]) object;
            if(file != null) {
                Map data = Collections.singletonMap(file.length == 0 ? "" : file[0].getName(), object);
                super.encode(data, MAP_STRING_WILDCARD, template);
                return;
            }
        }
        super.encode(object, bodyType, template);
    }

}

更换之前的配置

public class MultipartSupportConfig {
     @Bean
     @Primary
     @Scope("prototype")
     public Encoder feignFormEncoder() {
         return new FeignSpringFormEncoder();
     }
   }