Java(Spring boot)实现生成二维码

一、引入spring boot依赖：

   <!--引入生成二维码的依赖-->
   <!-- https://mvnrepository.com/artifact/com.google.zxing/core -->
   <dependency>
       <groupId>com.google.zxing</groupId>
       <artifactId>core</artifactId>
       <version>3.3.0</version>
   </dependency>
   <!-- https://mvnrepository.com/artifact/com.google.zxing/javase -->
   <dependency>
       <groupId>com.google.zxing</groupId>
       <artifactId>javase</artifactId>
       <version>3.3.0</version>
   </dependency>

二、工具类代码：

import com.google.zxing.*;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.common.HybridBinarizer;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.RoundRectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Hashtable;

/**
 * 二维码生成工具类
 */
public class QrCodeUtils {
    private static final String CHARSET = "utf-8";
    public static final String FORMAT = "JPG";
    // 二维码尺寸
    private static final int QRCODE_SIZE = 300;
    // LOGO宽度
    private static final int LOGO_WIDTH = 60;
    // LOGO高度
    private static final int LOGO_HEIGHT = 60;

    /**
     * 生成二维码
     *
     * @param content      二维码内容
     * @param logoPath     logo地址
     * @param needCompress 是否压缩logo
     * @return 图片
     * @throws Exception
     */
    public static BufferedImage createImage(String content, String logoPath, boolean needCompress) throws Exception {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
        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 (logoPath == null || "".equals(logoPath)) {
            return image;
        }
        // 插入图片
        QrCodeUtils.insertImage(image, logoPath, needCompress);
        return image;
    }

    /**
     * 插入LOGO
     *
     * @param source       二维码图片
     * @param logoPath     LOGO图片地址
     * @param needCompress 是否压缩
     * @throws IOException
     */
    private static void insertImage(BufferedImage source, String logoPath,
                                    boolean needCompress) throws Exception {
        File file = new File(logoPath);
        if (!file.exists()) {
            System.err.println(""+logoPath+"   该文件不存在！");
            return;
        }
        Image src = ImageIO.read(new File(logoPath));
        int width = src.getWidth(null);
        int height = src.getHeight(null);
        if (needCompress) { // 压缩LOGO
            if (width > LOGO_WIDTH) {
                width = LOGO_WIDTH;
            }
            if (height > LOGO_HEIGHT) {
                height = LOGO_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();
    }

    /**
     * 生成二维码（指定路径保存）
     *
     * @param content 内容
     * @param imgPath logo图片地址（内嵌图片）
     * @param destPath 生成二维码存放地址
     * @param needCompress 是否压缩logo
     * @throws Exception
     */
    public static void encode(String content, String imgPath, String destPath, boolean needCompress) throws Exception {
        BufferedImage image = QrCodeUtils.createImage(content, imgPath, needCompress);
        mkdirs(destPath);
        // String file = new Random().nextInt(99999999)+".jpg";
        // ImageIO.write(image, FORMAT_NAME, new File(destPath+"/"+file));
        ImageIO.write(image, FORMAT, new File(destPath));
    }

    /**
     * 生成二维码(直接将二维码以图片输出流返回）
     *
     * @param content 内容
     * @param imgPath logo图片地址（内嵌图片）
     * @param needCompress 是否压缩logo
     * @return
     * @throws Exception
     */
    public static BufferedImage encode(String content, String imgPath, boolean needCompress) throws Exception {
        BufferedImage image = QrCodeUtils.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();
        }
    }

    /**
     * 生成二维码(内嵌LOGO)
     *
     * @param content      内容
     * @param logoPath     LOGO地址
     * @param output       输出流
     * @param needCompress 是否压缩LOGO
     * @throws Exception
     */
    public static void encode(String content, String logoPath, OutputStream output, boolean needCompress)
            throws Exception {
        BufferedImage image = QrCodeUtils.createImage(content, logoPath, needCompress);
        ImageIO.write(image, FORMAT, output);
    }

    /**
     * 获取指定文件的输入流，获取logo
     *
     * @param logoPath 文件的路径
     * @return
     */
    public static InputStream getResourceAsStream(String logoPath) {
        return QrCodeUtils.class.getResourceAsStream(logoPath);
    }

    /**
     * 解析二维码
     *
     * @param file
     *            二维码图片
     * @return
     * @throws Exception
     */
    public static String decode(File file) throws Exception {
        BufferedImage image;
        image = ImageIO.read(file);
        if (image == null) {
            return null;
        }
        BufferedImageLuminanceSource source = new BufferedImageLuminanceSource(image);
        BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
        Result result;
        Hashtable<DecodeHintType, Object> hints = new Hashtable<DecodeHintType, Object>();
        hints.put(DecodeHintType.CHARACTER_SET, CHARSET);
        result = new MultiFormatReader().decode(bitmap, hints);
        String resultStr = result.getText();
        return resultStr;
    }

    /**
     * 解析二维码
     *
     * @param path
     *            二维码图片地址
     * @return
     * @throws Exception
     */
    public static String decode(String path) throws Exception {
        return QrCodeUtils.decode(new File(path));
    }

	//测试一：
    public static void main(String[] args) throws Exception {
        String text = "https://blog.csdn.net/weixin_43763430";
        String logoPath = "D:\\qrCode\\logo.jpg";
        String destPath = "D:\\qrCode\\csdn.jpg";
        QrCodeUtils.encode(text,logoPath,destPath,true);
    }
}

三、调用工具类生成二维码

1、将链接生成二维码图片并保存到指定路径

工具类中的主方法是指定了二维码链接的内容是博客地址，并保存在D:\qrCode\csdn.jpg，二维码嵌套了头像的图片，期望实现的是生成二维码后被扫码直接进入到博客也没。如若不嵌入头像，直接将logoPath参数设为null。

	//测试一：
    public static void main(String[] args) throws Exception {
        String text = "https://blog.csdn.net/weixin_43763430";
        String logoPath = "D:\\qrCode\\logo.jpg";
        String destPath = "D:\\qrCode\\csdn.jpg";
        QrCodeUtils.encode(text,logoPath,destPath,true);
    }

运行该主方法后，可在指定路径中看到生成的二维码图片。

2、将链接生成二维码直接显示在页面

运用spring boot生成二维码无需将保存二维码的图片，只须前端调用springboot接口即可在页面上显示二维码。实现了实时生成二维码。Controller层接口代码示例如下：

	@GetMapping("/anon/coupon/qrCodeTest")
    @ApiOperation(value = "获取二维码")
    public void qrCodeTest(HttpServletResponse response) throws Exception {
        String text = "https://blog.csdn.net/weixin_43763430";
        String logoPath = "D:\\qrCode\\logo.jpg";
        //String destPath = "D:\\qrCode\\csdn.jpg";
        QrCodeUtils.encode(text,logoPath,response.getOutputStream(),true);
    }

打开浏览器访问该接口地址，页面就会显示生成的二维码。扫描二维码即可进入到博客页面。

3、将以get请求传参链接生成二维码

二维码运用到各种业务中，通常需要根据不同用户识别其相对应的内容，如以上示例是访问的博客主页面，如若想根据访问者传递的参数访问博客中特定的文章，文章访问各篇文章是用的get请求方式，即可根据传参实现get请求传入不同参数生成二维码的内容不同。

	@GetMapping("/anon/coupon/qrCodeTest")
    @ApiOperation(value = "获取二维码")
    public void qrCodeTest(@RequestParam(value = "id") String id,HttpServletResponse response) throws Exception {
        String text = "https://blog.csdn.net/weixin_43763430/article/details/" + id;
        String logoPath = "D:\\qrCode\\logo.jpg";
        //String destPath = "D:\\qrCode\\csdn.jpg";
        QrCodeUtils.encode(text,logoPath,response.getOutputStream(),true);
    }

用浏览器访问该接口地址，页面生成二维码，用手机扫描二维码即可跳转到博客中该篇文章页面。

4、将以post请求传参链接生成二维码

求解？？？