Java擷取微信小程式二維碼（傳參）

采用的是wxacode.createQRCode擷取二維碼，此二維碼有調用次數限制（100000次）

微信小程式官方文檔位址：createQRCode

1.第一步擷取accessToken

/**
     * @return access_token
     * @throws Exception
     */
    public static String getAccessToken() throws Exception {
        String apiKey = "你的小程式apiKey";//小程式apiKey
        String secretKey = "你的小程式secretKey";//小程式密鑰
        String requestUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=" + apiKey + "&secret=" + secretKey;
        URL url = new URL(requestUrl);
        // 打開和URL之間的連接配接
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        // 設定通用的請求屬性
        connection.setRequestProperty("Content-Type", "application/json");
        connection.setRequestProperty("Connection", "Keep-Alive");
        connection.setUseCaches(false);
        connection.setDoOutput(true);
        connection.setDoInput(true);

        // 得到請求的輸出流對象
        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
        out.writeBytes("");
        out.flush();
        out.close();

        // 建立實際的連接配接
        connection.connect();
        // 定義 BufferedReader輸入流來讀取URL的響應
        BufferedReader in = null;
        if (requestUrl.contains("nlp")) {
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "GBK"));
        } else {
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(), "UTF-8"));
        }
        String result = "";
        String getLine;
        while ((getLine = in.readLine()) != null) {
            result += getLine;
        }
        in.close();
        JSONObject jsonObject = JSON.parseObject(result);
        String accesstoken = jsonObject.getString("access_token");
        return accesstoken;
    }
           

2.擷取小程式二維碼到本地

/**
     * 生成帶參小程式二維碼(輸出到本地)
     *
     * @param machineNo    機器編号
     * @param accessToken token
     */
    public static Map<String, Object> getMiniqrQrToLocal(String machineNo, String accessToken) {
        Map<String, Object> retMap = null;
        try {
            URL url = new URL("https://api.weixin.qq.com/cgi-bin/wxaapp/createwxaqrcode?access_token=" + accessToken);
//            URL url = new URL("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token=" + accessToken);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            // 發送POST請求必須設定如下兩行
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            httpURLConnection.setRequestMethod("POST");// 送出模式
            httpURLConnection.setRequestProperty("Content-Type", "application/x-javascript; charset=UTF-8");
            // 擷取URLConnection對象對應的輸出流
            PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
            // 發送請求參數
            JSONObject paramJson = new JSONObject();
			// 掃碼進入的小程式頁面路徑，最大長度 128 位元組，不能為空；對于小遊戲，可以隻傳入 query 部分，來實作傳參效果，如：傳入 "?foo=bar"，即可在 wx.getLaunchOptionsSync 接口中的 query 參數擷取到 {foo:"bar"}      
            paramJson.put("path", "pages/index/index?machineNo="+machineNo);//傳入機器編碼
            paramJson.put("width", 430);
            printWriter.write(paramJson.toString());
            // flush輸出流的緩沖
            printWriter.flush();
            //開始擷取資料
            BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream());
            /*ByteArrayOutputStream os = new ByteArrayOutputStream();*/
            OutputStream os = new FileOutputStream(new File("/Desktop/image/wechatImage.jpg"));//本機位置
            int len;
            byte[] arr = new byte[1024];
            while ((len = bis.read(arr)) != -1) {
                os.write(arr, 0, len);
                os.flush();
            }
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return retMap;
    }
           

3.測試使用

public static void main(String[] args) throws Exception {
        String accessToken = accessToken();
        System.out.println("擷取的accessToken:" + accessToken);
        //擷取二維碼
         getMiniqrQrToLocal("123",accessToken);
    }
           

4.小程式端接收參數

在page/index/index.js頁面中的onload函數接收即可

onLoad: function(e) {  
console.log("接收的機器參數為："+e.machineNo);
}