formData用ajax上传图片

源于http://blog.youkuaiyun.com/high2011/article/details/49679475

没有用框架,直接用java实现上传图片小功能

function doUpload() {  
	alert($( "#uploadForm" )[0]);
     var formData = new FormData($('#uploadForm')[0]);  
     $.ajax({  
          url: 'upload' ,  //请求
          type: 'POST',  //请求方式
          data: formData,  //数据类型,二进制文件
          async: false,  //同步
          cache: false,  
          contentType: false,  
          processData: false,  
          success: function (msg) {  //成功返回
              alert('success'+msg);  
          },  
          error: function (msg) {  //失败返回
              alert('error'+msg);  
          }  
     });  
}  

servlet用下面两个类就可以获取formData

FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);