html2canvas(document.body, { //截圖對象     //此處可配置詳細參數     onrendered: function(canvas) { //渲染完成回調canvas       canvas.id = "mycanvas";        // 生成base64圖片數據       var dataUrl = canvas.toDataURL('image/png');  //指定格式，也可不帶參數       var formData = new FormData(); //模擬表單對象       formData.append("imgData",convertBase64UrlToBlob(dataUrl)); //寫入數據       var xhr = new XMLHttpRequest(); //數據傳輸方法       xhr.open("POST", "../bulletin/exportPdf"); //配置傳輸方式及地址       xhr.send(formData);       xhr.onreadystatechange = function(){ //回調函數       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數據轉換為Blobfunction 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'});}

access-control-allow-origin: * access-control-allow-credentials: true

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"); //獲取數據    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, "導出失敗：服務器異常");    } 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;}