前端：
<form method="post" enctype="multipart/form-data" id="formSubmit"><div class="row"><div class="col-lg-12" style="padding-left:25px;padding-top: 5px"><label>请选择文件</label><input type="file" name="file" title="点击选择文件" multiple="" accept="*/*" class="form-control"></div></div><div class="row"><div style="padding-left:25px;padding-top:10px"><input type="submit" class="btn btn-primary"></div></div>
</form>

JS：
$('#formSubmit').submit(function (event) {//首先验证文件格式var fileName = $(this).find("input[name=file]").val();if (fileName === '') {alert('请选择文件');return;}// mulitipart form,如文件上传类var formData = new FormData(this);$.ajax({async: false,type: "POST",url: "/upload",data: formData,dataType: "JSON",mimeType: "multipart/form-data",contentType: false,cache: false,processData: false,success: function (data) {if (data.success) {layer.alert("上传成功")} else {layer.alert(data.error)}}});return false;});

java:@RequestMapping(value = "/upload", method = RequestMethod.POST, produces = "application/json;charset=utf-8")@ResponseBodypublic SimpleAjaxResponse uploadSingleFile(HttpServletRequest request, Model model) {try {DefaultMultipartHttpServletRequest httpServletRequest = (DefaultMultipartHttpServletRequest) request;MultipartFile multipartFile = httpServletRequest.getFile("file");return new SimpleAjaxResponse(true);} catch (Exception e) {LOGGER.error(e.getMessage(), e);e.printStackTrace();return new SimpleAjaxResponse("上传出错了");}}