SpringCloud---Feign上传下载详解

1.使用原因

公司最近做的项目在用SpringCloud，设计到了上传。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。

@Beanpublic 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)@ResponseBodypublic 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.

原文地址：https://www.cnblogs.com/technologykai/p/9335029.html