生成二维码

package com.ywsoftware.oa.util;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.util.Base64;
import java.util.HashMap;
import java.util.Map;

public class QrCodeUtil {

    /**
     * 创建base64二维码图片
     */
    public static String createQrCodeBase64Pic(String content) throws Exception {
        // 图像宽度
        int width = 139;
        // 图像高度
        int height = 139;
        // 图像类型
        String format = "png";
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        // 生成矩阵
        BitMatrix bitMatrix = new MultiFormatWriter().encode(content,
                BarcodeFormat.QR_CODE, width, height, hints);
        BufferedImage image = MatrixToImageWriter.toBufferedImage(bitMatrix);
        //新建流
        ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();
        //利用ImageIO类提供的write方法，将bi以png图片的数据模式写入流。
        ImageIO.write(image, format, arrayOutputStream);
        //从流中获取数据数组。
        byte[] bytes = arrayOutputStream.toByteArray();
        return "data:image/png;base64," + Base64.getEncoder().encodeToString(bytes);
    }
}

源码里偷来的

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.Hashtable;
import java.util.Map;
import javax.imageio.ImageIO;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class ZxingUtils {
    private static Log log = LogFactory.getLog(ZxingUtils.class);
    private static final int BLACK = -16777216;
    private static final int WHITE = -1;

    public ZxingUtils() {
    }

    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, 1);

        for(int x = 0; x < width; ++x) {
            for(int y = 0; y < height; ++y) {
                image.setRGB(x, y, matrix.get(x, y) ? -16777216 : -1);
            }
        }

        return image;
    }

    private static void writeToFile(BitMatrix matrix, String format, File file) throws IOException {
        BufferedImage image = toBufferedImage(matrix);
        if (!ImageIO.write(image, format, file)) {
            throw new IOException("Could not write an image of format " + format + " to " + file);
        }
    }

    public static File getQRCodeImge(String contents, int width, String imgPath) {
        return getQRCodeImge(contents, width, width, imgPath);
    }

    public static File getQRCodeImge(String contents, int width, int height, String imgPath) {
        try {
            Map<EncodeHintType, Object> hints = new Hashtable();
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
            hints.put(EncodeHintType.CHARACTER_SET, "UTF8");
            BitMatrix bitMatrix = (new MultiFormatWriter()).encode(contents, BarcodeFormat.QR_CODE, width, height, hints);
            File imageFile = new File(imgPath);
            writeToFile(bitMatrix, "png", imageFile);
            return imageFile;
        } catch (Exception var7) {
            log.error("create QR code error!", var7);
            return null;
        }
    }
}