Jquery实现异步上传文件

<form action="upload.do" id="upForm" method="post" enctype="multipart/form-data">
<table id="table_report" class="table table-striped table-bordered table-hover">
? ? <tr>
? ? ? ? <td>批量文件:</td>
? ? ? ? <td><input type="file" name="myfile"></td>
?? ?</tr>
?? ?<tr>
? ? ? ? <td><button type="button" id="saveBtn" class="btn btn-primary">提交</button></td>
?? ?</tr>
</table>
</form>

var uploading = false;
if(uploading){
? ? bootbox.alert("文件正在上传中，请稍候!");
?? ?return false;
}
$.ajax({
? ? url:"upload.do",
?? ?type: "POST",//方法类型
?? ?cache : false,//
?? ?processData: false,
?? ?contentType: false,
?? ?dataType:"json",
?? ?//data:$('#upForm').serialize(),
?? ?data: new FormData($('#upForm')[0]),
?? ?beforeSend: function(){
?? ??? ?uploading = true;
?? ??? ?console.log(uploading);
?? ?},
?? ?success: function(data){
?? ??? ?var json=eval('(' + data + ')');
?? ??? ?if(json.result=="success"){
?? ??? ??? ?bootbox.alert("操作成功!");
?? ??? ?}else{
?? ??? ??? ?bootbox.alert(json.msg);
?? ??? ?}
?? ??? ?uploading = false;
?? ?},error:function(){
?? ??? ?bootbox.alert("请求失败!");
?? ?}
});

@RequestMapping(value="/upload",method = RequestMethod.POST)
@ResponseBody
public String upfile(@RequestParam("myfile")MultipartFile myfile,
? ? MultipartHttpServletRequest request) {
? ? logger.info("===上传文件===");
?? ?Map<String, String> map = new HashMap<String, String>();
?? ?if (request.getContentLength() > 0) {
?? ? ? ?String fileName = myfile.getOriginalFilename();
?? ??? ?InputStream inputStream = null;
?? ??? ?inputStream = myfile.getInputStream();
? ? ? ? //TODO拿这inputstream,可以随心所欲了
? ? }?
}