java生成二维码

导入相关依赖

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

生成二维码工具类

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.util.Hashtable;

public class QrCodeUtils {

    private static final int BLACK = 0xFF000000;

    private static final int WHITE = 0xFFFFFFFF;

    private static final int WIDTH = 430;

    private static final int HEIGHT = 430;

    /**
     * 生成二维码图片
     * @param text
     * @return
     */
    public static String generateQRCode(String text) throws Exception{

            //1.生成二维码
            Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            BitMatrix bitMatrix = new MultiFormatWriter().encode(text, BarcodeFormat.QR_CODE, WIDTH, HEIGHT, hints);

            //2.转化成byte[]格式
            BufferedImage image = toBufferedImage(bitMatrix);
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            ImageIO.write(image, "png", out);
            byte[] bytes = out.toByteArray();

            String path = null;
            if (null != bytes && bytes.length > 0) {
                //3.上传图片服务器（个人实现）
                path = "上传图片后返回的图片路径";
            }

            return path;
    }

    /**
     * 格式转换
     * @param matrix
     * @return
     */
    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) ? BLACK : WHITE);
            }
        }
        return image;
    }

}

学自：https://blog.youkuaiyun.com/qq_28953809/article/details/81698422