1. 必要的配置⚓

它们也使用了commons-fileupload，所以同样需要导入此包：

<!-- https://mvnrepository.com/artifact/commons-fileupload/commons-fileupload -->
<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.4</version>
</dependency>

都需要配置CommonsMultipartResolver：

<!-- 多部分文件上传 -->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
    <property name="defaultEncoding" value="UTF-8" />
    <!--100MB-->
    <property name="maxUploadSize" value="104857600" />
    <!--4KB-->
    <property name="maxInMemorySize" value="4096" />
    <!--10MB-->
    <property name="maxUploadSizePerFile" value="10485760"/>
</bean>

html页面：

<form action="/blog/blog/UploadFile1" method="post" enctype="multipart/form-data">
    文件上传
    <input type="file" name="any"><br>
    <button type="submit">上传</button>
</form>

2. 流⚓

    /**
     * 以流的方式上传文件
     * @param multipartFile 文件
     */
    @PostMapping("/UploadFile1")
    public Result uplodFile1(@RequestParam("any") MultipartFile multipartFile) {
        FileOutputStream fo = null;
        InputStream is = null;
        boolean flag = false;
        try {
            ServletContext context = request.getServletContext();
            String path = context.getRealPath("/WEB-INF/classes/files");

            //输出流
            fo = new FileOutputStream(path + File.separator + multipartFile.getOriginalFilename());

            //输入流
            is = multipartFile.getInputStream();

            int len;
            byte[] buffer = new byte[1024];
            while ((len=is.read(buffer)) != -1) {
                fo.write(buffer, 0, len);
            }
            fo.flush();
            flag = true;
        }catch (IOException e){
            e.printStackTrace();
        }finally {
            if (fo != null){
                try {
                    fo.close();
                }catch (IOException e){
                    System.out.println("close failed");
                }
            }
            if (is != null){
                try {
                    is.close();
                }catch (IOException e){
                    System.out.println("close failed");
                }
            }
        }

        if (flag){
            return new Result(StatusCode.SUCCESS, "上传成功");
        }else {
            return new Result(StatusCode.FAILED, "上传失败");
        }
    }

3. MultipartFile⚓

/**
 * file.transferTo 保存
 */
@PostMapping("/UploadFile2")
public Result uploadFile2(@RequestParam("any") MultipartFile multipartFile){
    File file = new File("D:/logs/" + multipartFile.getOriginalFilename());
    try {
        multipartFile.transferTo(file);
    }catch (IOException e){
        e.printStackTrace();
        return new Result(StatusCode.FAILED, "上传失败");
    }
    return new Result(StatusCode.SUCCESS, "上传成功");
}

4. CommonsMultipartResolver⚓

/**
 * 采用spring提供的上传文件的方法
 */
@PostMapping("/UploadFile3")
public Result uploadFile3(HttpServletRequest request){
    CommonsMultipartResolver resolver = new CommonsMultipartResolver(request.getServletContext());

    if (!resolver.isMultipart(request)){
        return new Result(StatusCode.FAILED, "上传内容类型错误");
    }

    MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;

    Iterator<String> iterator = multipartRequest.getFileNames();
    try {
        while (iterator.hasNext()){
            MultipartFile multipartFile = multipartRequest.getFile(iterator.next());
            multipartFile.transferTo(new File("D:/logs/" + multipartFile.getOriginalFilename()));
        }
    }catch (IOException e){
        e.printStackTrace();
        return new Result(StatusCode.FAILED, "上传失败");
    }

    return new Result(StatusCode.SUCCESS, "上传成功");
}

5. 使用vue、axio上传文件⚓

<input type="file" id="blog" placeholder="选择文件"/>
<button @click="uploadBlog">上传博客</button>

uploadBlog: function () {
    let file = document.getElementById('blog').files[0]
    let param = new FormData()
    param.append('any', file)
    console.log(param.get('any'))
    this.$axios.post('/api/blog/blog/UploadFile3', param, {
        headers: {
          'Content-Type': 'multipart/form-data'
        }
    })
}