android studio 使用post方法

    /**
     * 将图片转换成Base64编码的字符串
     */
    public String bitmaptoString(Bitmap bitmap) {
     

        // 将Bitmap转换成字符串

        String string = null;

        ByteArrayOutputStream bStream = new ByteArrayOutputStream();

        bitmap.compress(CompressFormat.PNG, 100, bStream);

        byte[] bytes = bStream.toByteArray();

        string = Base64.encodeToString(bytes, Base64.DEFAULT);

        return string;

    }

    /**
     * init engine
     * call in onCreate
     *
     * @return
     */
    private String onRunModel() {
     

        try {
     
            String assetImagePath="images/1.jpg";
            InputStream imageStream = getAssets().open(assetImagePath);
            Bitmap image = BitmapFactory.decodeStream(imageStream);
            String params=bitmaptoString(image);

            Log.d("params", "params_base64: "+params);

            String strUrlPath = "http://192.168.2.44:8080/TestServer/" ;

            URL url=new URL(strUrlPath);
            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
//            httpURLConnection.setConnectTimeout(3000);     //设置连接超时时间
            httpURLConnection.setDoInput(true);                  //打开输入流，以便从服务器获取数据
            httpURLConnection.setDoOutput(true);                 //打开输出流，以便向服务器提交数据
            httpURLConnection.setRequestMethod("POST");     //设置以Post方式提交数据
            httpURLConnection.setUseCaches(false);               //使用Post方式不能使用缓存
            //设置请求体的类型是文本类型
            httpURLConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

            httpURLConnection.connect(); //连接即往服务端发送消息
            DataOutputStream dop=new DataOutputStream(httpURLConnection.getOutputStream());
            dop.writeBytes("data="+URLEncoder.encode(params,"utf-8"));
            dop.flush();//清空缓存
            dop.close();//关闭

            //下面开始做接收工作
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(httpURLConnection.getInputStream()));
            String result="";
            String readLine=null;
            while((readLine=bufferedReader.readLine())!=null){
     
                result+=readLine;
            }
            bufferedReader.close();
            httpURLConnection.disconnect();
            String strResult = URLDecoder.decode(result,"utf-8");
            Log.d("strResult", "strResult: "+strResult);

            try {
     
                JSONObject json = new JSONObject(result);

                JSONArray ReceiptLines=json.getJSONArray("ReceiptLines");
                Log.d("ReceiptLines", "ReceiptLines: "+ReceiptLines);
                return String.valueOf(ReceiptLines);

            } catch (JSONException e) {
     
                e.printStackTrace();
                return "";
            }
        } catch (IOException e) {
     
            e.printStackTrace();
            return "";
        }
    }


    private void onRunModelSuccessed(String result) {
     


        Log.i(TAG, "onRunModelSuccessed");
        textView.setText(result); //输出结果
        imageView.setImageBitmap(predictor.outputImage);
    }