spring mvc 用ajaxSubmit 在iE8上传文件变下载的问题

前端代码

<form method="post" enctype="multipart/form-data" id="cooperatorIdentityBackPhotoForm">
<label class="Con_Label">法人身份证反面</label>
<div class="Con_Input">
<input type="file" id="IdDn" class="file" size="1"
onchange="FileValue(this.id)" name="cooperatorIdentityBackPhoto"> <input type="button"
id="IdDn1" value="浏览" class="file_button" name="cooperatorIdentityBackPhoto"/>
<input type="button" value="上传" class="file_button2" id="uploadCooperatorIdentityBackPhoto">
</div></form>

<script>

$("#cooperatorIdentityBackPhotoForm").ajaxSubmit({
url: "<c:url value='/uploadCooperatorIdentityBackPhoto'/>",
dataType: "json",//指定格式
success: function(data) {
if(data.success){

}else{
alert(data.msg);
}
},
error: function() {
alert("上传失败，请重新上传！");
},
});

</script>

后台代码

//用的是import com.fasterxml.jackson.databind.ObjectMapper;

 

@RequestMapping(value = "/uploadCooperatorBussessPhoto", method = RequestMethod.POST, produces = "text/html; charset=UTF-8")//指定返回格式
@ResponseBody
public String uploadInspectorIdentityNoPhoto(
@RequestPart("cooperatorBussessPhoto") MultipartFile cooperatorBussessPhoto)
throws IOException {
Map<String, Object> map = new HashMap<String, Object>();


map.put("url", "success");
return mapper.writeValueAsString(map);//将map对象转为json
}