// 獲取小程序服務實例
WxMaService wxMaService = WxMaConfiguration.getWxMaService();

// 獲取小程序二維碼生成實例
WxMaQrcodeService wxMaQrcodeService = wxMaService.getQrcodeService();

// 設置小程序二維碼線條顏色為黑色
WxMaCodeLineColor lineColor = new WxMaCodeLineColor("0", "0", "0");

// 生成二維碼圖片字節(jié)流（此處也可以生成File類型，如果想將圖片文件保存到服務器就生成File類型，此處生成byte[]類型，方便直接返回文件流到前端）
byte[] qrCodeBytes = null;
qrCodeBytes = wxMaQrcodeService.createWxaCodeUnlimitBytes(String.valueOf(id), null, 430, false, lineColor, false);

@RestController
@RequestMapping("/qrCode")
public class QrCodeController {
 private static final Logger logger = LoggerFactory.getLogger(QrCodeController.class);

 @GetMapping("/getMiniappQrCode/{id}")
 public void getMiniappQrCode(@PathVariable("id") Long id, HttpServletRequest request, HttpServletResponse response) throws Exception{
  // 獲取小程序服務實例
  WxMaService wxMaService = WxMaConfiguration.getWxMaService();
  // 獲取小程序二維碼生成實例
  WxMaQrcodeService wxMaQrcodeService = wxMaService.getQrcodeService();

  // 設置小程序二維碼線條顏色為黑色
  WxMaCodeLineColor lineColor = new WxMaCodeLineColor("0", "0", "0");

  // 生成二維碼圖片字節(jié)流
  byte[] qrCodeBytes = null;
  try{
   qrCodeBytes = wxMaQrcodeService.createWxaCodeUnlimitBytes(String.valueOf(id), null, 430, false, lineColor, false);
  } catch(Exception e){
   logger.error("生成小程序碼出錯", e);
  }

  // 設置contentType
  response.setContentType("image/png");

  // 寫入response的輸出流中
  OutputStream stream = response.getOutputStream();
  stream.write(qrCodeBytes);
  stream.flush();
  stream.close();
 }
}