java生成指定内容二维码工具类及其用法：

首先导入zxing相关pom依赖

        <!--二维码生成识别组件--><dependency><groupId>com.google.zxing</groupId><artifactId>core</artifactId><version>3.3.3</version></dependency><dependency><groupId>com.google.zxing</groupId><artifactId>javase</artifactId><version>3.3.3</version></dependency>

工具了如下： 

       

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.shanjupay.common.domain.BusinessException;
import com.shanjupay.common.domain.CommonErrorCode;
import org.apache.commons.lang.StringUtils;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;/*** <P>* 二维码工具类* </p>*/
public class QRCodeUtil {/*** 生成二维码* @param content* @param width* @param height* @return*/public String createQRCode(String content, int width, int height) throws IOException {String resultImage = "";//除了尺寸，传入内容不能为空if (!StringUtils.isEmpty(content)) {ServletOutputStream stream = null;ByteArrayOutputStream os = new ByteArrayOutputStream();//二维码参数@SuppressWarnings("rawtypes")HashMap<EncodeHintType, Comparable> hints = new HashMap<>();//指定字符编码为“utf-8”hints.put(EncodeHintType.CHARACTER_SET, "utf-8");//L M Q H四个纠错等级从低到高，指定二维码的纠错等级为M//纠错级别越高，可以修正的错误就越多，需要的纠错码的数量也变多，相应的二维吗可储存的数据就会减少hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);//设置图片的边距hints.put(EncodeHintType.MARGIN, 1);try {//zxing生成二维码核心类QRCodeWriter writer = new QRCodeWriter();//把输入文本按照指定规则转成二维吗BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);//生成二维码图片流BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);//输出流ImageIO.write(bufferedImage, "png", os);/*** 原生转码前面没有 data:image/png;base64 这些字段，返回给前端是无法被解析，所以加上前缀*/resultImage = new String("data:image/png;base64," + EncryptUtil.encodeBase64(os.toByteArray()));return resultImage;} catch (Exception e) {e.printStackTrace();throw new BusinessException(CommonErrorCode.E_200007);} finally {if (stream != null) {stream.flush();stream.close();}}}return null;}public static void main(String[] args) throws IOException {QRCodeUtil qrCodeUtil = new QRCodeUtil();//生成一个指向百度搜索的二维码。（将返回结果复制到浏览器地址框即可出现二维码图片）System.out.println(qrCodeUtil.createQRCode("https://www.baidu.com/", 200, 200));}}

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