ajax java base64 图片储存

js代码//利用formdata上传

 var dataUrl = $('#canvas').getDataUrl();
 var img = $('<img>').attr('src', dataUrl);     //显示图片
 var oMyForm = new FormData();     //创建formdata
 var blobBin = dataURLtoBlob(dataUrl);     //base64转换blob
 oMyForm.append("blobObject", blobBin);    //想formData添加blob数据
 $.ajax({
         url: $.getUrl()+"activity/updateImg",
         type: "POST",
         data: oMyForm,
         async: false,
         cache: false,
         contentType: false,
         processData: false,
         success: function (msg) {
              console.log("yes");
         }
 }); //**dataURL to blob**  dataURL转换blob
 function dataURLtoBlob(dataurl) {
    var arr = dataurl.split(','), mime = arr[0].match(/:(.*?);/)[1],
    bstr = atob(arr[1]), n = bstr.length, u8arr = new Uint8Array(n);
    while (n--) {
         u8arr[n] = bstr.charCodeAt(n);
    }
    return new Blob([u8arr], { type: mime });
 }

java代码 //spring mvc

 @RequestMapping(value="updateImg",method=RequestMethod.POST)
 public void upLoad(HttpServletRequest request,HttpServletResponse response) throws IOException {
       System.out.println("enter...");
       // 从请求中获取到文件信息需要将请求转换为MultipartHttpServletRequest类型
       MultipartHttpServletRequest MulRequest = request instanceof MultipartHttpServletRequest ? (MultipartHttpServletRequest) request : null;
       Iterator<String> fileNames = MulRequest.getFileNames();
       byte[] imgByte = null;
       if (fileNames.hasNext()) { // 遍历请求中的图片信息
          String fileName = fileNames.next(); // 图片对应的参数名
          MultipartFile file = MulRequest.getFile(fileName); // 获取到图片
          if (file != null) {
              System.out.println("file.getSize():" + file.getSize()); // 图片大小
              imgByte=file.getBytes();// 可以获取到图片的字节数组
          }
         }       for(int i=0;i<imgByte.length;++i)
       {
          if(imgByte[i]<0)
          {//调整异常数据
              imgByte[i]+=256;
          }
       }
       //生成jpeg图片
       String imgFilePath = "d://222.jpg";//新生成的图片
       OutputStream out = new FileOutputStream(imgFilePath);
       out.write(imgByte);
       out.flush();
       out.close();
     }