1、页面部分
引入的样式、js

jquery.fileupload.css
jquery-1.8.2.min.js
jquery.ui.widget.js
jquery.fileupload.js

页面

<div class="btn btn-primary btn-sm fileinput-button" id="hide-button">
  <i class="glyphicon glyphicon-plus"></i>
  <span>上传</span>
  <input id="imageFile" type="file" name="imageFile">
</div>

绑定事件

$('#' + fileId).fileupload({
    url: '/upload/image?type=' + type,
    add: function (e, data) {
          var uploadErrors = [];
          var acceptFileTypes = /^image\/(png|jpe?g)$/i;
          //文件类型判断
          if (!acceptFileTypes.test(data.originalFiles[0]['type'])) {
             return false;
          }
         //文件大小判断
          if (data.originalFiles[0]['size'] > 5000 * 1024) {
               return false;
          }
          if (uploadErrors.length > 0) {
                    return false;
                } else {
                    data.submit();
                }
          },
          done: function (e, data) {
                ......
          }
 });

2、java部分

@RestController
@RequestMapping("/file")
public class FileController {
    private final Logger logger = LoggerFactory.getLogger(getClass());

    @Value("${app.file.upload.server.origin}")
    private String origin;
    @Value("${app.file.upload.server.path}")
    private String realPath;
    @Value("${app.file.upload.dir.userPicture}")
    private String userPicturePath;
    @Value("${app.file.upload.size.max.image}")
    private int imageFileMaxSize;

    @PostMapping("/upload/image")
    public Result uploadImage(@RequestParam MultipartFile imageFile) {
        validateImageFile(imageFile);
        String dateDIR = DateFormatUtils.format(new Date(), "yyyyMMdd");
        String path = userPicturePath + dateDIR + "/";
        // 为上传的文件进行重命名（避免同名文件的相互覆盖）使用UUID + 文件后缀
        String suffix = imageFile.getOriginalFilename().substring(imageFile.getOriginalFilename().lastIndexOf("."));
        String fileName = UUID.randomUUID().toString() + suffix;
        File file = new File(realPath + path + fileName);
        if (!file.getParentFile().exists()) {
            file.mkdirs();
        }
        //将临时文件保存到磁盘
        try {
            imageFile.transferTo(file);
        } catch (IOException e) {
            logger.error("文件上传失败", e);
            throw new ServiceException("上传失败：" + e.getMessage());
        }
        Map<Object, Object> data = Maps.newLinkedHashMap();
        data.put("url", origin + path + fileName);
        return ResultGenerator.genSuccessResult(data);
    }

    private void validateImageFile(MultipartFile imageFile) throws ServiceException {
        //校验类型
        if (imageFile.getContentType().indexOf("image") == -1) {
            throw new ServiceException("上传失败，仅支持图片类型！");
        }
        if (imageFile.getSize() > (imageFileMaxSize * 1024 * 1024)) {
            throw new ServiceException("上传失败，文件大小不能超过" + imageFileMaxSize + "MB！");
        }
    }
}