<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>core</artifactId>
    <version>3.4.1</version>
</dependency>
<dependency>
    <groupId>com.google.zxing</groupId>
    <artifactId>javase</artifactId>
    <version>3.4.1</version>
</dependency>

package com.example.qrcode.service;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class QrCodeService {

    /**
     * 生成二維碼
     *
     * @param content 二維碼內(nèi)容
     * @param width   二維碼寬度
     * @param height  二維碼高度
     * @param filePath 二維碼保存路徑
     * @throws WriterException
     * @throws IOException
     */
    public void generateQRCode(String content, int width, int height, String filePath) throws WriterException, IOException {
        // 設(shè)置二維碼參數(shù)
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8"); // 設(shè)置字符編碼
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 設(shè)置容錯(cuò)級(jí)別
        hints.put(EncodeHintType.MARGIN, 2); // 設(shè)置邊距

        // 創(chuàng)建二維碼生成器
        QRCodeWriter qrCodeWriter = new QRCodeWriter();
        BitMatrix bitMatrix = qrCodeWriter.encode(content, BarcodeFormat.QR_CODE, width, height, hints);

        // 創(chuàng)建圖片
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        image.createGraphics();

        Graphics2D graphics = (Graphics2D) image.getGraphics();
        graphics.setColor(Color.WHITE);
        graphics.fillRect(0, 0, width, height);
        graphics.setColor(Color.BLACK);
        for (int i = 0; i < width; i++) {
            for (int j = 0; j < height; j++) {
                if (bitMatrix.get(i, j)) {
                    graphics.fillRect(i, j, 1, 1);
                }
            }
        }

        // 保存圖片
        File outputFile = new File(filePath);
        ImageIO.write(image, "png", outputFile);
    }
}

package com.example.qrcode.controller;

import com.example.qrcode.service.QrCodeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class QrCodeController {

    @Autowired
    private QrCodeService qrCodeService;

    /**
     * 生成二維碼接口
     *
     * @param content 二維碼內(nèi)容
     * @param width   二維碼寬度
     * @param height  二維碼高度
     * @param filePath 二維碼保存路徑
     * @return
     */
    @GetMapping("/generateQRCode")
    public String generateQRCode(@RequestParam String content, @RequestParam int width, @RequestParam int height, @RequestParam String filePath) {
        try {
            qrCodeService.generateQRCode(content, width, height, filePath);
            return "二維碼生成成功，保存路徑為：" + filePath;
        } catch (Exception e) {
            e.printStackTrace();
            return "二維碼生成失?。? + e.getMessage();
        }
    }
}

http://localhost:8080/generateQRCode?content=Hello%20World&width=200&height=200&filePath=D:/qrcode.png