小程序生成二维码(B接口)保存到服务器

• 1.先获取access_token 

• 2.组装小程序需要的参数

• 3.请求微信返回图片的二进制流

• 4.保存到服务器

1.获取access_token 保存到redis服务器

/**
     * 获取小程序的ACCESS_TOKEN
     */
    public static String getAccessToken(RedisService redisService) {

        //从redis中获取小程序的token
        String access_token = redisService.get(\"access_token_samll\");
        if (StringUtil.isNullOrEmpty(access_token)) {
            //获取小程序的access_token
            String jsonParam = HttpUtil.get(WxSPConfig.ACCESS_TOKEN_SMALL_PROGRAM.replace(\"APPID\", WxSPConfig.APP_ID_SMALL_PROGRAM).replace(\"APPSECRET\", WxSPConfig.SECRET_SMALL_PROGRAM));
            Map<String,  > json2Map = FastJsonUtil.json2Map(jsonParam);
            access_token= String.valueOf(json2Map.get(\"access_token\"));
            Long expires_in = Long.valueOf(String.valueOf(json2Map.get(\"expires_in\")));
            redisService.set(\"access_token_samll\", access_token,expires_in);
            return access_token;
        } else {
            return access_token;
        }
    }

2.组装小程序必要的参数

   private static final Logger logger = LoggerFactory.getLogger(GenerateQRCodeController.class);

    @Autowired
    private CompanyService companyService;

    @Autowired
    private RedisService redisService;

    @Value(\"${wx_pay.images}\")
    private String images;

    @Value(\"${media.image.url}\")
    private String url;

    @ApiOperation(value = \"生成QRCode\", notes = \"给指定的商家生成小程序二维码\")
    @GetMapping(\"/code/{sn}\")
    public ResponseBean generate(@PathVariable String sn) throws IOException {
        CompanyEntity companyEntity = companyService.findBySn(sn);
        if (companyEntity == null) {
            return ResponseUtil.failure(\"当前商户不存在\");
        }
        if (!StringUtil.isNullOrEmpty(companyEntity.getQrCode())) {
            return ResponseUtil.failure(\"当前商户已存在小程序二维码\");
        }
        String accessToken = AccessTokenUtil.getAccessToken(redisService);
        Map<String,  > map = new HashMap<String,  >();
        map.put(\"scene\", companyEntity.getSn());
        map.put(\"page\", \"pages/index/index\");
        map.put(\"width\", 1280);//二维码宽度
        String json = FastJsonUtil.toJson(map);
        logger.info(\"map={}\", json);
        //如果正常返回是图片的二进制内容
        byte[] bytes = HttpUtil.doPostJsonResponseImage(WxSPConfig.WX_ACODE_UNLIMIT.replace(\"ACCESS_TOKEN\", accessToken).toString().replace(\"\\\"\", \"\"), json);
        String path = images + companyEntity.getSn() + \".png\";
        logger.info(\"小程序二维码保存路径={}\",path);
        File file = new File(images);
        if (!file.exists()) {
            file.mkdirs();
        }
        //设置到公司下面
        companyEntity.setQrCode(url+\"qrcode/\"+companyEntity.getSn()+\".png\");
        companyService.save(companyEntity);

        //保存到服务器
        InputStream is = new ByteArrayInputStream(bytes);
        OutputStream out = new FileOutputStream(new File(path));
        copyFile(is, out);
        out.close();
        is.close();
        return ResponseUtil.success();
    }

    private static void copyFile(InputStream is, OutputStream os) throws IOException {
        byte[] b = new byte[1024];
        int len = 0;
        while ((len = is.read(b)) != -1) {
            os.write(b, 0, len);
        }
        os.flush();
    }

4.保存到服务器

默认奇妙的在替换请求微信二维码的接口时,出现了两个双引号导致我 调了很长时间的bug

在替换access_token的时候