zxing 生成二维码与条形码

导包

        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>core</artifactId>
            <version>3.4.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.zxing</groupId>
            <artifactId>javase</artifactId>
            <version>3.4.0</version>
        </dependency>

工具类

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 com.google.zxing.oned.Code128Writer;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import org.springframework.util.StringUtils;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class CodeUtil {
        //二维码
    public static String getQRCode(String content, int width, int height) {
        if (!StringUtils.isEmpty(content)) {
            ServletOutputStream stream = null;

            HashMap<EncodeHintType, Comparable> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            hints.put(EncodeHintType.MARGIN, 0);

            try {
                QRCodeWriter writer = new QRCodeWriter();
                BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);

                BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);
                ByteArrayOutputStream os = new ByteArrayOutputStream();
                ImageIO.write(bufferedImage, "png", os);

                BASE64Encoder encoder = new BASE64Encoder();
                String resultImage = new String("data:image/png;base64," + encoder.encode(os.toByteArray()));

                return resultImage;
            } catch (Exception e) {
            } finally {
                if (stream != null) {
                    try {
                        stream.flush();
                        stream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return null;
    }
        //条形码
    public static String getBarCode(String content, int width, int height) {
        try {
            Map<EncodeHintType, Object> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
            hints.put(EncodeHintType.MARGIN, 0);

            int realWidth = getBarCodeNoPaddingWidth(width, content, width);

            BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.CODE_128, realWidth, height, hints);

            BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            ImageIO.write(bufferedImage, "png", os);

            BASE64Encoder encoder = new BASE64Encoder();
            String resultImage = new String("data:image/png;base64," + encoder.encode(os.toByteArray()));

            return resultImage;
        } catch (Exception e) {
            return null;
        }
    }

    private static int getBarCodeNoPaddingWidth(int expectWidth, String contents, int maxWidth) {
        boolean[] code = new Code128Writer().encode(contents);

        int inputWidth = code.length;

        double outputWidth = (double) Math.max(expectWidth, inputWidth);
        double multiple = outputWidth / inputWidth;

        //优先取大的
        int returnVal = 0;
        int ceil = (int) Math.ceil(multiple);
        if (inputWidth * ceil <= maxWidth) {
            returnVal = inputWidth * ceil;
        } else {
            int floor = (int) Math.floor(multiple);
            returnVal = inputWidth * floor;
        }

        return returnVal;
    }

}

使用

String QRCode = CodeUtil.getQRCode(random, QRWidth, QRHeight);//二维码
String BarCode = CodeUtil.getBarCode(random, BarWidth, BarHeight);//条形码

random ——自己生成的随机数，即二维码的内容
QRWidth —— 二维码的宽度
QRHeight —— 二维码的高度
QRCode —— 生成的Base64 字符串，返给前端使用

前端使用

<img src="QRCode" /> 直接引入即可

效果