微信支付：使用谷歌二维码工具把code_url生成二维码

1.加入依赖

<!-- google二维码生成包 -->
    <dependency>
        <groupId>com.google.zxing</groupId>
        <artifactId>javase</artifactId>
        <version>3.3.0</version>
    </dependency>
                        
    <dependency>
        <groupId>com.google.zxing</groupId>
        <artifactId>core</artifactId>
        <version>2.0</version>
    </dependency>

2.生成二维码

@RestController
//@RequestMapping("/user/api/v1/order")
@RequestMapping("/api/v1/order")
public class OrderController {


    @Autowired
    private VideoOrderService videoOrderService;

    @GetMapping("add")
    public void saveOrder(@RequestParam(value = "video_id",required = true)int videoId,
                          HttpServletRequest request,
                          HttpServletResponse response) throws Exception {

        //String ip = IpUtils.getIpAddr(request);
        //int userId = request.getAttribute("user_id");
        int userId = 1;    //临时写死的配置
        String ip = "120.25.1.43";
        VideoOrderDto videoOrderDto = new VideoOrderDto();
        videoOrderDto.setUserId(userId);
        videoOrderDto.setVideoId(videoId);
        videoOrderDto.setIp(ip);

        String codeUrl = videoOrderService.save(videoOrderDto);
        if(codeUrl == null) {
            throw new  NullPointerException();
        }

        try{
            //生成二维码配置
            Map<EncodeHintType,Object> hints =  new HashMap<>();

            //设置纠错等级
            hints.put(EncodeHintType.ERROR_CORRECTION,ErrorCorrectionLevel.L);
            //编码类型
            hints.put(EncodeHintType.CHARACTER_SET,"UTF-8");

            //构造一个图形
            BitMatrix bitMatrix = new MultiFormatWriter().encode(codeUrl,BarcodeFormat.QR_CODE,400,400,hints);
            OutputStream out =  response.getOutputStream();
　　　　　　　
　　　　　　　//通过流写出
            MatrixToImageWriter.writeToStream(bitMatrix,"png",out);

        }catch (Exception e){
            e.printStackTrace();
        }
    }
}