generic WXAQRCode

CreateWXAQRCode.java

    /**
     * 生成小程序二维码并存入本地
     *
     * @param pathAndParams   路径及自定义参数: /page/index?id=123
     * @param filePathAndName 文件路径及名称: C:/Files/qrcode/123.jpg
     */
    private static void generic(String pathAndParams, String filePathAndName) {
        RestTemplate rest = new RestTemplate();
        InputStream inputStream = null;
        OutputStream outputStream = null;
        try {
            String url = "https://api.weixin.qq.com/cgi-bin/wxaapp/createwxaqrcode?access_token=" + accessToken;
            Map<String, Object> param = new HashMap<>();
            param.put("path", pathAndParams);
            param.put("width", 430);
            HttpHeaders headers = new HttpHeaders();
            headers.setContentType(MediaType.APPLICATION_JSON);
            HttpEntity<Map<String, Object>> httpEntity = new HttpEntity<>(param, headers);
            ResponseEntity<byte[]> entity = rest.exchange(url, HttpMethod.POST, httpEntity, byte[].class);
            byte[] result = entity.getBody();
            inputStream = new ByteArrayInputStream(result);
            File file = new File(filePathAndName);
            if (!file.exists()) {
                boolean newFile = file.createNewFile();
                if (!newFile) {
                    System.err.println("创建文件失败：" + file.getAbsolutePath());
                    return;
                }
            }
            outputStream = new FileOutputStream(file);
            int len;
            byte[] buf = new byte[1024];
            while ((len = inputStream.read(buf, 0, 1024)) != -1) {
                outputStream.write(buf, 0, len);
            }
            outputStream.flush();
        } catch (Exception e) {
            System.out.println("生成二维码异常");
        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (outputStream != null) {
                try {
                    outputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }