方法一：ZXing

使用ZXing识别，可以返回二维码识别内容，还可以找到二维码的位置坐标。

1、引入依赖

    implementation group: 'com.google.zxing', name: 'core', version: '3.5.3'
    implementation group: 'com.google.zxing', name: 'javase', version: '3.5.3'

2、识别代码

import com.google.zxing.*;
import com.google.zxing.client.j2se.BufferedImageLuminanceSource;
import com.google.zxing.common.HybridBinarizer;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;

/**
 * @author zhengqian
 * @since 2024.12.26
 */
public class ZXingQRCode {

    public static void main(String[] args) {
        String urlPath = "https://url";
        zxing(urlPath);
    }

    public static void zxing(String urlPath) {
        try {
            // 读取二维码图片文件
//            File file = new File("二维码图片1.png");
//            BufferedImage image = ImageIO.read(file);
            
            URL url = new URL(urlPath);
            BufferedImage image = ImageIO.read(url);
            // 使用LuminanceSource和Binarizer将图片转化为二进制数据
            LuminanceSource source = new BufferedImageLuminanceSource(image);
            BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(source));
            // 创建一个解码器
            Result qrCodeResult = new MultiFormatReader().decode(bitmap);
            // 输出解码结果
            System.out.println("二维码内容： " + qrCodeResult.getText());
            // 解码
            ResultPoint[] resultPoint = qrCodeResult.getResultPoints();
            System.out.println("二维码坐标:\npoints1： " + resultPoint[0] + ",\npoints2： " + resultPoint[1] + ",\npoints3： "
                    + resultPoint[2] + ",\npoints4： " + resultPoint[3]);

            // 获得二维码坐标
            float point1X = resultPoint[0].getX();
            float point1Y = resultPoint[0].getY();
            float point2X = resultPoint[1].getX();
            float point2Y = resultPoint[1].getY();
            // 宽高
            final int w = (int) Math
                    .sqrt(Math.abs(point1X - point2X) * Math.abs(point1X - point2X) + Math.abs(point1Y - point2Y) * Math.abs(point1Y - point2Y))
                    + 12 * (7 - 1);
            final int h = w;
            System.out.println("二维码宽高：" + h);

        } catch (NotFoundException e) {
            System.out.println("二维码未找到");
            // 这里判断如果识别不了带LOGO的图片，重新添加上一个属性
            try {
                URL url = new URL(urlPath);
                BufferedImage image = ImageIO.read(url);
                LuminanceSource source = new BufferedImageLuminanceSource(image);
                Binarizer binarizer = new HybridBinarizer(source);
                BinaryBitmap binaryBitmap = new BinaryBitmap(binarizer);
                Map<DecodeHintType, Object> hints = new HashMap<>(3);
                // 设置编码格式
                hints.put(DecodeHintType.CHARACTER_SET, "UTF-8");
                // 设置优化精度
                hints.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
                // 设置复杂模式开启
                hints.put(DecodeHintType.PURE_BARCODE, Boolean.TYPE);
                // 解码
                Result result = new MultiFormatReader().decode(binaryBitmap, hints);
                System.out.println("图片中内容：  ");
                System.out.println("content： " + result.getText());
            } catch (IOException e1) {
                e1.printStackTrace();
            } catch (NotFoundException e1) {
                e1.printStackTrace();
            }
        } catch (IOException e) {
            System.out.println("二维码读取错误");
            e.printStackTrace();
        }
    }
}

方法二 使用opencv

1、引入依赖

    // opencv
    implementation group: 'org.bytedeco', name: 'opencv', version: '4.10.0-1.5.11'
    implementation group: 'org.bytedeco', name: 'javacpp', version: '1.5.11'
    implementation group: 'org.bytedeco', name: 'openblas', version: '0.3.28-1.5.11'
    implementation group: 'org.bytedeco', name: 'javacv-platform', version: '1.5.11'

2、识别代码

import org.bytedeco.opencv.opencv_core.Mat;
import org.bytedeco.opencv.opencv_core.StringVector;
import org.bytedeco.opencv.opencv_wechat_qrcode.WeChatQRCode;

import java.nio.charset.StandardCharsets;

import static org.bytedeco.opencv.global.opencv_imgcodecs.imread;

/**
 * @author zhengqian
 * @since 2024.12.26
 */
public class OpenCVQRCode {

    public static void main(String[] args) {
        String filePath = "二维码图片1.png";
        wechat(filePath);
    }

    public static void wechat(String filePath) {
        Mat img = imread(filePath);
        WeChatQRCode we = new WeChatQRCode();
        StringVector stringVector = we.detectAndDecode(img);
        if (stringVector.empty()) {
            System.out.println("not found");
        }
        System.out.println("识别内容：" + stringVector.get(0).getString(StandardCharsets.UTF_8));

        // 不过暂时不太清楚怎么输出二维码坐标。。。
    }
}