1.使用原因
公司最近做的项目在用SpringCloud，涉及到了上传。但是Feign本身是不支持文件类型的。所以这里把上传下载的实现分享一下。
2.所需配置
这是自己实现的一个formEncoder，可以支持单文件和数组的多文件上传
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.addWriter(new SpringSingleMultipartFileWriter());
processor.addWriter(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);
}
}
将实现的类注册一下。
@Bean
public Encoder feignEncoder(ObjectFactory<HttpMessageConverters> messageConverters) {
return new FeignSpringFormEncoder(new SpringEncoder(messageConverters));
}
调用方的代码，这里参数接收的时候用的是@RequestPart，与@RequestParam区别大家可以去查一下。
@PostMapping(value = "/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
@ResponseBody
public ApiResult upload(@RequestPart(value = "file") MultipartFile file) {
return fileUploadApiClient.upload(file);
}
暴露的fileUploadApiClient接口还需要添加依赖
<dependency>
<groupId>io.github.openfeign.form</groupId>
<artifactId>feign-form</artifactId>
<version>3.3.0</version>
</dependency>
<dependency>
<groupId>io.github.openfeign.form</groupId>
<artifactId>feign-form-spring</artifactId>
<version>3.3.0</version>
</dependency>
暴露的fileUploadApiClient代码，MediaType类型的指定
@PostMapping(value = "/oss/upload", consumes = MediaType.MULTIPART_FORM_DATA_VALUE, produces = MediaType.APPLICATION_JSON_VALUE)
ApiResult upload(@RequestPart(value = "file") MultipartFile file);
最后直接调用就可以上传成功.