Java实现二维码的生成与解析

Java实现二维码的生成

二维码 (dimensional barcode) ，又称二维条码，是在一维条码的基础上扩展出的一种具有可读性的条码。设备扫描二维条码，通过识别条码的长度和宽度中所记载的二进制数据，可获取其中所包含的信息。相比一维条码，二维码记载更复杂的数据，比如图片、网络链接等。

当然了，二维码是什么并不是我们今天研究的对象，你都进来看这篇文章了，肯定也知道什么是二维码啦~

入门案例

Google提供了XML生成的jar包，我们只需要导入其依赖使用即可， 站在巨人的肩膀上好乘凉~

<dependency>
  <groupId>com.google.zxing</groupId>
  <artifactId>core</artifactId>
  <version>3.3.0</version>
</dependency>
<dependency>
  <groupId>com.google.zxing</groupId>
  <artifactId>javase</artifactId>
  <version>3.3.0</version>
</dependency>

工具类代码

package cn.rayfoo.utils;

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.InputStream;
import java.io.OutputStream;
import java.util.Hashtable;

/**
 * @Author: rayfoo@qq.com
 * @Date: 2020/7/13 5:20 下午
 * @Description: 二维码工具类
 */


public class QRCodeUtil {

    //编码
    private static final String CHARSET = "utf-8";
    //文件格式
    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;

    /**
     * 生成二维码
     * @param content 内容
     * @param imgPath logo
     * @param needCompress 是否需要压缩
     * @return java.awt.image.BufferedImage
     * @throws Exception
     */
    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;
    }

    /**
     * 插入logo
     * @param source 二维码图片
     * @param imgPath logo路径
     * @param needCompress 是否压缩
     * @throws Exception
     */
    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); // 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();
    }

    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, String destPath, boolean needCompress) throws Exception {
        BufferedImage image = QRCodeUtil.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_NAME, new File(destPath));
    }

    /**
     * 生成二维码，获得到输入流 log内嵌
     * @param content 内容
     * @param imgPath logo路径
     * @param output 输入流
     * @param needCompress 是否压缩
     * @throws Exception
     */
    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);
    }

    /**
     * 获取指定的logo文件输入流
     * @param logoPath logo路径
     * @return java.io.InputStream
     */
    public static InputStream getResourceAsStream(String logoPath) {
        return QRCodeUtil.class.getResourceAsStream(logoPath);
    }

    /**
     * 将要解析的二维码的存放路径
     * @param file 要解析的二维码
     * @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 hints = new Hashtable();
        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 要解析的二维码路径
     * @return
     * @throws Exception
     */
    public static String decode(String path) throws Exception {
        return QRCodeUtil.decode(new File(path));
    }
}

测试类代码

package cn.rayfoo.utils.test;

import cn.rayfoo.utils.QRCodeUtil;

/**
 * @Author: rayfoo@qq.com
 * @Date: 2020/7/13 5:20 下午
 * @Description:
 */
public class TestApp {
    public static void main(String[] args) throws Exception {
        // 存放在二维码中的内容
        String text = "http://blog.vantee.cn";
        // 嵌入二维码的图片路径
        String imgPath = "/Users/rayfoo/Downloads/logo.jpg";
        // 生成的二维码的路径及名称
        String destPath =  "/Users/rayfoo/Downloads/MyQRCode.png";
        //生成二维码
        QRCodeUtil.encode(text, imgPath, destPath, true);
        // 解析二维码
        String str = QRCodeUtil.decode(destPath);
        // 打印出解析出的内容
        System.out.println(str);
    }
}

方法介绍：

QRCodeUtil.encode(text, imgPath, destPath, true);

方法说明：

使用encode方法生成二维码

• text：放入二维码中的内容
• imgPath：嵌入二维码的图片路径
• destPath：二维码的输出路径
• needCompress：是否压缩二维码

QRCodeUtil.decode(recode);

解析二维码：

• recode：二维码路径

参考文章：CSDN地址