Java 二维码QRCode生成与解析

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.common.BitMatrix;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
 
public class QRCodeGenerator {
 
    public static void generateQRCodeImage(String text, int width, int height, String filePath)
            throws WriterException, IOException {
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        BitMatrix bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, width, height);
        File file = new File(filePath);
        ImageIO.write(toBufferedImage(bitMatrix), "png", file);
    }
 
    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.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, matrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
        return image;
    }
 
    public static void main(String[] args) {
        try {
            generateQRCodeImage("Hello, World!", 350, 350, "hello_world.png");
        } catch (WriterException | IOException e) {
            e.printStackTrace();
        }
    }
}

这段代码使用了com.google.zxing库来生成一个包含文本 "Hello, World!" 的二维码图片，并将其保存为PNG格式的文件。generateQRCodeImage方法接受文本、宽度、高度和文件路径作为参数，使用QRCodeWriter类生成二维码，并使用ImageIO.write将其输出为图片。在主方法中，我们调用generateQRCodeImage方法生成一个二维码图片。