javaweb二維碼頁面下載

頁面二維碼生成下載

1.前端js

/**
 * 批量生成二維碼
 */
function createCode() {
    using('datagrid', function() {
        var selectedRows = $('#eptGrid').datagrid('getSelections');
        if ($('#eptGrid').datagrid('getRows').length <= 0) {
            $.toast({
                heading : '提示',
                text : '沒有需要生成的數據',
                position : 'top-right',
                loaderBg : '#878787',
                hideAfter : 2000
            });
            return false;
        }
        if (selectedRows.length > 0) {
            for (var i = 0; i < selectedRows.length; i++) {
                downloadFile(appPath + '/ept/createCode?id='+selectedRows[i]["EPT_ID"]+'&code='+selectedRows[i]["EPT_CODE"]);
            }
        }

        
    });
}

 

//隱藏節點，下載文件
function downloadFile(url){     
      
      var elemIFrame = document.createElement('iframe');     
      
      elemIFrame .src = url;     
      
      elemIFrame .style.display = "none";     
      
      $('body').append(elemIFrame);
}

 

後端代碼

@RequestMapping(value = "createCode", method = RequestMethod.GET)
    @ResponseBody
    public void createCode(HttpServletRequest request, HttpServletResponse response) {
        try {
            QrCodeCreateUtil qrCodeCreateUtil = new QrCodeCreateUtil();
            String id = request.getParameter("EPT_ID");
            String code = request.getParameter("code");
            String content = "********************/doGetQrCodeInfo?id=";
            BufferedImage image = qrCodeCreateUtil.createQrCode(response, content + id, 900, "PNG");
            response.addHeader("Content-Disposition", "attachment;filename=" + code + ".png"); //通知頁面下載該文件
            ImageIO.write(image, "PNG", response.getOutputStream());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

 

//生成二維碼

 public BufferedImage createQrCode(HttpServletResponse response, String content, int qrCodeSize, String imageFormat) throws WriterException, IOException{  
            //設置二維碼糾錯級別ＭＡＰ
            Hashtable<EncodeHintType, ErrorCorrectionLevel> hintMap = new Hashtable<EncodeHintType, ErrorCorrectionLevel>();  
            hintMap.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);  // 矯錯級別  
            QRCodeWriter qrCodeWriter = new QRCodeWriter();  
            //創建比特矩陣(位矩陣)的QR碼編碼的字符串  
            BitMatrix byteMatrix = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, qrCodeSize, qrCodeSize, hintMap);  
            // 使BufferedImage勾畫QRCode  (matrixWidth 是行二維碼像素點)
            int matrixWidth = byteMatrix.getWidth();  
            BufferedImage image = new BufferedImage(matrixWidth-200, matrixWidth-200, BufferedImage.TYPE_INT_RGB);  
            image.createGraphics();  
            Graphics2D graphics = (Graphics2D) image.getGraphics();  
            graphics.setColor(Color.WHITE);  
            graphics.fillRect(0, 0, matrixWidth, matrixWidth);  
            // 使用比特矩陣畫並保存圖像
            graphics.setColor(Color.BLACK);  
            for (int i = 0; i < matrixWidth; i++){
                for (int j = 0; j < matrixWidth; j++){
                    if (byteMatrix.get(i, j)){
                        graphics.fillRect(i-100, j-100, 1, 1);  
                    }
                }
            }
            //return ImageIO.write(image, imageFormat, response.getOutputStream());  
            return image;  
    }  
      
    /**
     * 讀二維碼並輸出攜帶的信息
     */
    public static void readQrCode(InputStream inputStream) throws IOException{  
        //從輸入流中獲取字符串信息
        BufferedImage image = ImageIO.read(inputStream);  
        //將圖像轉換爲二進制位圖源
        LuminanceSource source = new BufferedImageLuminanceSource(image);  
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));  
        QRCodeReader reader = new QRCodeReader();  
        Result result = null ;  
        try {
         result = reader.decode(bitmap);  
        } catch (ReaderException e) {
            e.printStackTrace();  
        }
        System.out.println("讀取code="+result.getText());  
    }