html2canvas(document.body, { //截圖對象
     //此處可配置詳細參數(shù)
     onrendered: function(canvas) { //渲染完成回調canvas
       canvas.id = "mycanvas"; 
       // 生成base64圖片數(shù)據(jù)
       var dataUrl = canvas.toDataURL('image/png');  //指定格式，也可不帶參數(shù)
       var formData = new FormData(); //模擬表單對象
       formData.append("imgData", convertBase64UrlToBlob(dataUrl), "123.png"); //寫入數(shù)據(jù)
       var xhr = new XMLHttpRequest(); //數(shù)據(jù)傳輸方法
       xhr.open("POST", "../bulletin/exportPdf"); //配置傳輸方式及地址
       xhr.send(formData);
       xhr.onreadystatechange = function(){ //回調函數(shù)
         if(xhr.readyState == 4){
            if (xhr.status == 200) {
               var back = JSON.parse(xhr.responseText);
               if(back.success == true){
                 alertBox({content: 'Pdf導出成功！',lock: true,drag: false,ok: true});
               }else{
                 alertBox({content: 'Pdf導出失敗！',lock: true,drag: false,ok: true});
               }
            }
         }
       };
     }
}); 
  
//將以base64的圖片url數(shù)據(jù)轉換為Blob
function convertBase64UrlToBlob(urlData){
  //去掉url的頭，并轉換為byte
  var bytes=window.atob(urlData.split(',')[1]);    
  //處理異常,將ascii碼小于0的轉換為大于0
  var ab = new ArrayBuffer(bytes.length);
  var ia = new Uint8Array(ab);
  for (var i = 0; i < bytes.length; i++) {
    ia[i] = bytes.charCodeAt(i);
  }
  return new Blob( [ab] , {type : 'image/png'});
}

String base64 = Img.split(",")[1];
BASE64Decoder decode = new BASE64Decoder(); 
byte[] imgByte = decode.decodeBuffer(base64);

@RequestMapping("/exportPdf")
public @ResponseBody void exportPdf(MultipartHttpServletRequest request,HttpServletResponse response)throws ServletException, IOException {
  ResultData result = new ResultData();  //自定義結果格式
  String filePath = "c:\\exportPdf2.pdf";
  String imagePath = "c:\\exportImg2.bmp";
  Document document = new Document(); 
  try{
    Map getMap = request.getFileMap();
    MultipartFile mfile = (MultipartFile) getMap.get("imgData"); //獲取數(shù)據(jù)
    InputStream file = mfile.getInputStream();
    byte[] fileByte = FileCopyUtils.copyToByteArray(file);
      
    FileImageOutputStream imageOutput = new FileImageOutputStream(new File(imagePath));//打開輸入流
    imageOutput.write(fileByte, 0, fileByte.length);//生成本地圖片文件
    imageOutput.close();
      
    PdfWriter.getInstance(document, new FileOutputStream(filePath)); //itextpdf文件
//    document.setPageSize(PageSize.A2);
    document.open();
    document.add(new Paragraph("JUST TEST ..."));
    Image image = Image.getInstance(imagePath); //itext-pdf-image
    float heigth = image.getHeight(); 
        float width = image.getWidth(); 
        int percent = getPercent2(heigth, width);  //按比例縮小圖片
        image.setAlignment(Image.MIDDLE); 
        image.scalePercent(percent+3);
    document.add(image);
    document.close();
  
    result.setSuccess(true);
    operatelogService.addOperateLogInfo(request, "導出成功：成功導出簡報Pdf");
  }catch (DocumentException de) {
    System.err.println(de.getMessage());
  }
  catch (Exception e) {
    e.printStackTrace();
    result.setSuccess(false);
    result.setErrorMessage(e.toString());
    try {
      operatelogService.addOperateLogError(request, "導出失?。悍掌鳟惓?);
    } catch (Exception e1) {
      e1.printStackTrace();
    }
  }
  response.getWriter().print(JSONObject.fromObject(result).toString());
}

private static int getPercent2(float h, float w) {
  int p = 0;
  float p2 = 0.0f;
  p2 = 530 / w * 100;
  p = Math.round(p2);
  return p;
}