SMM生成二维码

1.在pom.xml添加生成二维码的依赖包：

 <!--二维码 -->     <dependency>       <groupId>com.google.zxing</groupId>       <artifactId>core</artifactId>       <version>3.3.1</version>     </dependency>     <dependency>       <groupId>com.google.zxing</groupId>       <artifactId>javase</artifactId>       <version>3.3.1</version>     </dependency> 

2.然后是controller层代码：

@RequestMapping("/getQRCode")  public void getQRCode(HttpServletRequest request, HttpServletResponse response)    throws Exception {   String text = "你好，朋友！";///二维码输出的文本内容   // 通过调用写作工具类，获得图片流   ByteArrayOutputStream out = QRCodeUtil.encodeIO(text, "D:\\缓存元气壁纸\\img\\0cb7c825fe3fec52b45a46491290a7df.jpg", true);   // 定义返回参数   response.setCharacterEncoding("UTF-8");   response.setContentType("image/jpeg;charset=UTF-8");   response.setContentLength(out.size());   ServletOutputStream outputStream = response.getOutputStream();   outputStream.write(out.toByteArray());   outputStream.flush();   outputStream.close();  } 

3.二维码工具类QRCodeUtil：

 public class QRCodeUtil {      private static final String CHARSET = "utf-8";     private static final String FORMAT_NAME = "JPG";     // 二维码尺寸     private static final int QRCODE_SIZE = 300;     // LOGO宽度     private static final int WIDTH = 60;     // LOGO高度     private static final int HEIGHT = 60;      private static BufferedImage createImage(String content, String imgPath,                                              boolean needCompress) throws Exception {         Hashtable hints = new Hashtable();         hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);         hints.put(EncodeHintType.CHARACTER_SET, CHARSET);         hints.put(EncodeHintType.MARGIN, 1);         BitMatrix bitMatrix = new MultiFormatWriter().encode(content,                 BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);         int width = bitMatrix.getWidth();         int height = bitMatrix.getHeight();         BufferedImage image = new BufferedImage(width, height,                 BufferedImage.TYPE_INT_RGB);         for (int x = 0; x < width; x  ) {             for (int y = 0; y < height; y  ) {                 image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000                         : 0xFFFFFFFF);             }         }         if (imgPath == null || "".equals(imgPath)) {             return image;         }         // 插入图片         QRCodeUtil.insertImage(image, imgPath, needCompress);         return image;     }       private static void insertImage(BufferedImage source, String imgPath,                                     boolean needCompress) throws Exception {         File file = new File(imgPath);         if (!file.exists()) {             System.err.println("" imgPath "   文件不存在！");             return;         }         Image src = ImageIO.read(new File(imgPath));         int width = src.getWidth(null);         int height = src.getHeight(null);         if (needCompress) { // 压缩LOGO             if (width > WIDTH) {                 width = WIDTH;             }             if (height > HEIGHT) {                 height = HEIGHT;             }             Image image = src.getScaledInstance(width, height,                     Image.SCALE_SMOOTH);             BufferedImage tag = new BufferedImage(width, height,                     BufferedImage.TYPE_INT_RGB);             Graphics g = tag.getGraphics();             g.drawImage(image, 0, 0, null); // 画缩小图             g.dispose();             src = image;         }         // 插入LOGO         Graphics2D graph = source.createGraphics();         int x = (QRCODE_SIZE - width) / 2;         int y = (QRCODE_SIZE - height) / 2;         graph.drawImage(src, x, y, width, height, null);         Shape shape = new RoundRectangle2D.Float(x, y, width, width, 6, 6);         graph.setStroke(new BasicStroke(3f));         graph.draw(shape);         graph.dispose();     }      ///获取生成二维码的图片流     public static ByteArrayOutputStream encodeIO(String content,String imgPath,Boolean needCompress) throws Exception {         BufferedImage image = QRCodeUtil.createImage(content, imgPath,                 needCompress);         ///创建存储图片二进制流的输出流         ByteArrayOutputStream baos = new ByteArrayOutputStream();         ///将二进制数据写入ByteArrayOutputStream         ImageIO.write(image, "jpg", baos);         return baos;     } } 

4.Jsp代码： 定义按钮，定义二维码框架的长度和宽度

<span class="btnAll" id="ewm">【二维码】</span> <div id"dlg2" title="二维码信息" style="width: 320px; height: 350px; padding: 10px; top: 30px">
    <div style="float: left;">
        <img src="" id="npcImg" width="300" height="300" />
    </div>
</div>

5.JS代码：

<script>
    // 监听
    $(".btnAll").click(function() {

        if ($(this).html() == "【二维码】") {
            var img = document.getElementById("npcImg");
            img.src = "${pageContext.request.contextPath}/file/getQRCode";
        }
    });
</script>