在网站开发中,经常会遇到要生成二维码的情况，比如要使用微信支付、网页登录等，本文分享一个Spring Boot生成二维码的例子,这里用到了google的zxing工具类。
主要应用场景如下：
信息获取（名片、地图、WIFI密码、资料）网站跳转（跳转到微博、手机网站、网站）广告推送（用户扫码，直接浏览商家推送的视频、音频广告）手机电商（用户扫码、手机直接购物下单）防伪溯源（用户扫码、即可查看生产地；同时后台可以获取最终消费地)优惠促销（用户扫码，下载电子优惠券，抽奖）会员管理（用户手机上获取电子会员信息、VIP服务）手机支付（扫描商品二维码，通过银行或第三方支付提供的手机端通道完成支付）账号登录（扫描二维码进行各个网站或软件的登录）
1.引入jar包
pom.xml中引入zxing的jar包。
<!-- 二维码支持包 -->
<dependency><groupId>com.google.zxing</groupId><artifactId>core</artifactId><version>3.2.0</version>
</dependency>
<dependency><groupId>com.google.zxing</groupId><artifactId>javase</artifactId><version>3.2.0</version>
</dependency>
2.编写工具类
QRCodeUtil.java代码如下：
/*** QRCodeUtil 生成二维码工具类*/
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 + " 该文件不存在！");return;}Image src = ImageIO.read(new File(imgPath));int width = src.getWidth(null);int height = src.getHeight(null);if (needCompress) {
// 压缩LOGOif (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); // 绘制缩小后的图g.dispose();src = image;}// 插入LOGOGraphics2D 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();}public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);mkdirs(destPath);ImageIO.write(image, FORMAT_NAME, new File(destPath));}public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);return image;}public static void mkdirs(String destPath) {
File file = new File(destPath);// 当文件夹不存在时，mkdirs会自动创建多层目录，区别于mkdir．(mkdir如果父目录不存在则会抛出异常)if (!file.exists() && !file.isDirectory()) {
file.mkdirs();}}public static void encode(String content, String imgPath, OutputStream output, boolean needCompress)throws Exception {
BufferedImage image = QRCodeUtil.createImage(content, imgPath, needCompress);ImageIO.write(image, FORMAT_NAME, output);}public static void encode(String content, OutputStream output) throws Exception {
QRCodeUtil.encode(content, null, output, false);}
}
3.编写控制层代码
QrCodeController.java代码如下：
/*** 根据 url 生成 普通二维码*/@RequestMapping(value = "/createCommonQRCode")public void createCommonQRCode(HttpServletResponse response, String url) throws Exception {
ServletOutputStream stream = null;try {
stream = response.getOutputStream();//使用工具类生成二维码QRCodeUtil.encode(url, stream);} catch (Exception e) {
e.getStackTrace();} finally {
if (stream != null) {
stream.flush();stream.close();}}}/*** 根据 url 生成 带有logo二维码*/@RequestMapping(value = "/createLogoQRCode")public void createLogoQRCode(HttpServletResponse response, String url) throws Exception {
ServletOutputStream stream = null;try {
stream = response.getOutputStream();String logoPath = Thread.currentThread().getContextClassLoader().getResource("").getPath() + "templates" + File.separator + "logo.jpg";//使用工具类生成二维码QRCodeUtil.encode(url, logoPath, stream, true);} catch (Exception e) {
e.getStackTrace();} finally {
if (stream != null) {
stream.flush();stream.close();}}}
4.运行并查看效果
本项目中提供了生成普通二维码和带有logo二维码的两个接口，启动项目，我们来演示下生成下http://www.baidu.com这个url的二维码；
生成普通二维码
本地浏览器打开http://127.0.0.1:8089/createCommonQRCode?url=https://www.baidu.com，生成的二维码截图如下：
生成带logo的二维码
本地浏览器打开http://127.0.0.1:8089/createLogoQRCode?url=https://www.baidu.com，生成的二维码截图如下：
