j2ee之页面无刷新上传附件

//上传附件
var uploadAnnex = function(){
    //alert("??");
    //document.getElementById(‘submitFile‘).onclick = function(event){
        var applicationId = $("#applicationId").val();
        if(event.preventDefault){//取消按钮默认提交行为
            event.preventDefault();
        } else {
            event.returnValue = false;
        }
        var formDOM = document.getElementById(‘fileForm‘);
        var formData = new FormData(formDOM);//创建formData对象
        var req = new XMLHttpRequest();
        req.open("POST",  baseUrl +"/suspicious/upLoadFile?applicationId="+applicationId);//使用POST发送请求
        req.onload = function(event){
            if(this.status === 200){
                console.log(this.response);//请求成功后打印返回的结果
            }
        }
        req.send(formData);
        req = null;
    //}
}