java生成微信小程序二维码_java生成普通二维码跳转小程序

public class Qrutil {
    public static String postToken(String appId,String appKey) throws Exception{
        String requestUrl = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid="+appId+"&secret="+appKey;
        URL url = new URL(requestUrl);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setRequestProperty("Content-Type","application/json");
        connection.setRequestProperty("Connection","Keep-Alive");
        connection.setUseCaches(false);
        connection.setDoInput(true);
        connection.setDoOutput(true);
        //得到请求的输出流对象
        DataOutputStream out = new DataOutputStream(connection.getOutputStream());
        out.writeBytes("");
        out.flush();
        out.close();
        //建立实际的链接
        connection.connect();
        //定义bufferdreader输入流来读取url的响应
        BufferedReader in;
        if(requestUrl.contains("nIp")){
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(),"GBK"));
        }else {
            in = new BufferedReader(new InputStreamReader(connection.getInputStream(),"UTF-8"));
        }
        StringBuilder result = new StringBuilder();
        String getLine;
        while ((getLine=in.readLine())!=null){
            result.append(getLine);
        }
        in.close();
        JSONObject jsonObject = new JSONObject(result.toString());
        return jsonObject.getStr("access_token");
    }

    public static void generateQrCode(String filePath,String page,String scene,String accessToken){
        try{
            //调用微信接口生成二维码
            URL url = new URL("https://api.weixin.qq.com/wxa/getwxacodeunlimit?access_token="+accessToken);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setConnectTimeout(10000);
            httpURLConnection.setReadTimeout(2000);
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
            //发送请求参数
            JSONObject paramJson = new JSONObject();
            //二维码里携带的参数
            paramJson.put("scene",scene);
            //该接口传入的是page而不是path
            paramJson.put("page",page);
            //扫描二维码后跳转的页面
            paramJson.put("width",200);
            paramJson.put("is_hyaline",true);
            paramJson.put("auto_color",true);
            //要打开的小程序版本。正式版为 "release"，体验版为 "trial"，开发版为 "develop"。默认是正式版。
            paramJson.put("env_version","develop");
            printWriter.write(paramJson.toString());
            //flush输出流缓冲
            printWriter.flush();
            //开始获取数据
            BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream());
            OutputStream os = new FileOutputStream(new File(filePath));
            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();
        }
    }

}