Java生成二维码（附工具类）

article/2025/9/23 22:35:51

后台Java生成二维码

这里用到了谷歌的zxing包，maven依赖如下：

		<!-- 二维码依赖开始--><dependency><groupId>com.google.zxing</groupId><artifactId>core</artifactId><version>3.4.0</version></dependency><!-- 二维码依赖结束-->

一、场景

需要根据设备信息生成二维码，然后写回给前端去下载。

二、工具类代码

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Component;import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Hashtable;/*** 生成二维码工具类.** @author linzp* @version 1.0.0* CreateDate 2021/1/26 10:39*/
@Slf4j
@Component
public class QrCodeUtils {//二维码宽度private static final int QRCODE_SIZE = 430;//编码private static final String CHARSET = "utf-8";// 二维码绘制高度偏移量，留出空间写文字描述二维码信息private static final int OFFSET_HEIGHT = 25;//二维码标题字体private static final String TITLE_FONT = "黑体";//标题前缀private static final String TITLE_PREFIX = "编号：";/*** 生成二维码.** @param content 内容* @return 图片*/public BufferedImage buildQrCodeImage(String content) {return createImage(content, content);}/*** 生成二维码.** @param content 扫描成功的内容* @param title 二维码标题* @return 二维码图片*/private BufferedImage createImage(String content, String title) {//等同于hashmap,hashtable是线程安全的Hashtable hints = new Hashtable();hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);hints.put(EncodeHintType.CHARACTER_SET, CHARSET);hints.put(EncodeHintType.MARGIN, 1);BitMatrix bitMatrix = null;try {bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, QRCODE_SIZE, QRCODE_SIZE, hints);} catch (WriterException e) {log.error("生成二维码异常了..content【{}】", content, e);throw new RuntimeException("生成二维码信息异常，请稍后重试");}int width = bitMatrix.getWidth();int height = bitMatrix.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, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);}}log.info("生成二维码成功！");//有标题，合成带标题的二维码if (StringUtils.isNotBlank(title)) {return drawDetailForQR(image, title);}//直接返回生成的二维码return image;}/*** 绘制二维码描述信息.** @param source 源二维码图片* @param title  二维码标题* @return 合成后的图片*/private BufferedImage drawDetailForQR(BufferedImage source, String title) {//新建模板图片BufferedImage bufferedImage = new BufferedImage(QRCODE_SIZE, QRCODE_SIZE + OFFSET_HEIGHT, BufferedImage.TYPE_INT_RGB);Graphics2D graphics = bufferedImage.createGraphics();//绘制矩形背景graphics.setColor(Color.white);graphics.fillRect(0, 0, QRCODE_SIZE, OFFSET_HEIGHT);//绘制描述信息Font font = new Font(TITLE_FONT, Font.PLAIN, 22);graphics.setColor(Color.black);graphics.setFont(font);graphics.drawString(TITLE_PREFIX + title, 20, OFFSET_HEIGHT - 2);//绘制二维码graphics.drawImage(source, 0, OFFSET_HEIGHT, QRCODE_SIZE, QRCODE_SIZE, null);graphics.dispose();return bufferedImage;}
}