几行代码，轻松带你实现Java生成二维码功能！

<!--生成二维码-->
<dependency>
  <groupId>com.google.zxing</groupId>
  <artifactId>javase</artifactId>
  <version>3.3.0</version>
</dependency>

package com.bennyrhys.mall.util;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.WriterException;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;

import java.io.IOException;
import java.nio.file.FileSystems;
import java.nio.file.Path;

/**
 * 描述：     生成二维码工具
 */
public class QRCodeGenerator {


    public static void generateQRCodeImage(String text, int width, int height, String filePath)
            throws WriterException, IOException {
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        BitMatrix bitMatrix = qrCodeWriter.encode(text, BarcodeFormat.QR_CODE, width, height);
        Path path = FileSystems.getDefault().getPath(filePath);
        MatrixToImageWriter.writeToPath(bitMatrix, "PNG", path);
    }

    public static void main(String[] args) {
        try {
            generateQRCodeImage("Hello World", 350, 350, "E:/JAVA/mall/src/main/resources/images/QRTest.png");
        } catch (WriterException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

   /**
     * 生成二维码
     * 图片可解析出访问的支付对应订单号的支付连接
     * @param orderNo 订单号
     * @return 返回图片地址
     */
    @Override
    public String qrcode(String orderNo) {
        ServletRequestAttributes attributes = (ServletRequestAttributes) RequestContextHolder.getRequestAttributes();
        HttpServletRequest request = attributes.getRequest();

        String address = ip + ":" + request.getLocalPort();
        String payUrl = "http://" + address + "/pay?orderNo=" + orderNo;
        try {
            QRCodeGenerator.generateQRCodeImage(payUrl, 350, 350, Constant.FILE_UPLOAD_PATH + orderNo + ".png");
        } catch (WriterException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        String pngAddress = "http://" + address + "/images-dev/" + orderNo + ".png";
        return pngAddress;
    }

# 指定IP(防止ip转发获取的是内网ip) 
file.upload.ip=127.0.0.1