layui 图片上传+表单提交+ Spring MVC

<div class="layui-form-item">
    <label class="layui-form-label">修改头像</label>
    <div class="layui-input-inline uploadHeadImage">
        <div class="layui-upload-drag" id="headImg">
            <i class="layui-icon"></i>
            <p>点击上传图片，或将图片拖拽到此处</p>
        </div>
    </div>
    <div class="layui-input-inline">
        <div class="layui-upload-list">
            <img class="layui-upload-img headImage" src="http://t.cn/RCzsdCq" id="demo1">
            <p id="demoText"></p>
        </div>
    </div>
</div>

<script type="text/javascript">
    layui.use(["jquery", "upload", "form", "layer", "element"], function () {
        var $ = layui.$,
            element = layui.element,
            layer = layui.layer,
            upload = layui.upload,
            form = layui.form;
        //拖拽上传
        var uploadInst = upload.render({
            elem: ‘#headImg‘
            , url: ‘/upload/headImg‘
            , size: 500
            , before: function (obj) {
                //预读本地文件示例，不支持ie8
                obj.preview(function (index, file, result) {
                    $(‘#demo1‘).attr(‘src‘, result); //图片链接（base64）
                });
            }
            , done: function (res) {
                //如果上传失败
                if (res.code > 0) {
                    return layer.msg(‘上传失败‘);
                }
                //上传成功
                //打印后台传回的地址: 把地址放入一个隐藏的input中, 和表单一起提交到后台, 此处略..
                /*   console.log(res.data.src);*/
                window.parent.uploadHeadImage(res.data.src);
                var demoText = $(‘#demoText‘);
                demoText.html(‘<span style="color: #8f8f8f;">上传成功!!!</span>‘);
            }
            , error: function () {
                //演示失败状态，并实现重传
                var demoText = $(‘#demoText‘);
                demoText.html(‘<span style="color: #FF5722;">上传失败</span> <a class="layui-btn layui-btn-mini demo-reload">重试</a>‘);
                demoText.find(‘.demo-reload‘).on(‘click‘, function () {
                    uploadInst.upload();
                });
            }
        });
        element.init();
    });
</script>

/**
 * 个人信息上传
 * @return {Result}
 */
@RequestMapping(value = "/upload/headImg", method = {RequestMethod.POST})
@ResponseBody
public Object headImg(@RequestParam(value="file",required=false) MultipartFile file, HttpServletRequest request, HttpServletResponse response) throws Exception {
    if (SecurityUtils.getSubject().isAuthenticated() == false) {
        return "redirect:/backEnd/login";
    }
    String prefix="";
    String dateStr="";
    //保存上传
     OutputStream out = null;
    InputStream fileInput=null;
    try{
        if(file!=null){
            String originalName = file.getOriginalFilename();
            prefix=originalName.substring(originalName.lastIndexOf(".")+1);
             dateStr = format.format(new Date());
            String filepath = request.getServletContext().getRealPath("/static") + uploadDir + dateStr + "." + prefix;
            filepath = filepath.replace("\\", "/");
            File files=new File(filepath);
            //打印查看上传路径
            System.out.println(filepath);
            if(!files.getParentFile().exists()){
                files.getParentFile().mkdirs();
            }
            file.transferTo(files);
        }
    }catch (Exception e){
    }finally{
        try {
            if(out!=null){
                out.close();
            }
            if(fileInput!=null){
                fileInput.close();
            }
        } catch (IOException e) {
        }
    }
    Map<String,Object> map2=new HashMap<>();
    Map<String,Object> map=new HashMap<>();
    map.put("code",0);
    map.put("msg","");
    map.put("data",map2);
    map2.put("src","../../../static"+uploadDir + dateStr + "." + prefix);
    return map;
}