POST方式提交数据报错

我是做安卓的，今天写了个用POST方式向服务器提交数据，一直提交不了，代码也不报错，打印出来是这个java.lang.NumberFormatException:Invalid int: 8081
这个8081是我的服务器端口号，求大神解答，谢谢！！

8081是不是字符串，要转换成int

这是我的代码 要怎么转换啊
public class HttpUtils {

public static String submitPostData(String strUrlPath, Map<String,String> params,String encode){

    byte[] data = getRequestData(params,encode).toString().getBytes();//获得请求体
    try {
        URL url = new URL(strUrlPath);
        HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
        httpURLConnection.setConnectTimeout(3000);//设置连接超时时间
        httpURLConnection.setDoInput(true);
        httpURLConnection.setDoOutput(true);

        httpURLConnection.setRequestMethod("POST");
        httpURLConnection.setUseCaches(false);

        httpURLConnection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");

        httpURLConnection.setRequestProperty("Content-Length",String.valueOf(data.length));

        OutputStream outputStream = httpURLConnection.getOutputStream();
        outputStream.write(data,0,data.length);
        outputStream.close();
        int response = httpURLConnection.getResponseCode();
        if (response == HttpURLConnection.HTTP_OK){
            InputStream inputStream = httpURLConnection.getInputStream();

            return dealResponseResult(httpURLConnection.getInputStream(),encode);
        }
    } catch (IOException e) {
        e.printStackTrace();
        return "err: "+e.getMessage().toString();
    }
    return "-1";
}

private static StringBuffer getRequestData(Map<String, String> params, String encode) {

    StringBuffer stringBuffer = new StringBuffer();
        try {
            for (Map.Entry<String,String> entry : params.entrySet()){
            stringBuffer.append(entry.getKey())
                    .append("=")
                    .append(URLEncoder.encode(entry.getValue(),encode))
                    .append("&");
        }
        stringBuffer.deleteCharAt(stringBuffer.length() - 1);
    }catch (Exception e){
            e.printStackTrace();
    }
    return stringBuffer;
}

private static String dealResponseResult(InputStream inputStream,String encode) {
    String resultData = null;
    ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    byte[] data = new byte[1024];
    int len = 0;
    if (inputStream != null) {
        try {
            while ((len = inputStream.read(data)) != -1) {
                byteArrayOutputStream.write(data, 0, len);
            }
            resultData = new String(byteArrayOutputStream.toByteArray(),encode);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return resultData;
}

}

public class MainActivity extends AppCompatActivity{

private Button post_btn;
private TextView result;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    result = (TextView) findViewById(R.id.result);
    post_btn = (Button) findViewById(R.id.btn);
    post_btn.setOnClickListener(new View.OnClickListener(){
        @Override
        public void onClick(View view) {
            post_btn_OnClick(view);
        }
    });
}

private void post_btn_OnClick(View view){
    String strRecSmsMsg = "收短信测试";
    RecSmsToPost(strRecSmsMsg);
}
private void RecSmsToPost(String strRecSmsMsg){
    String strNowDateTime = getNowDateTime("yyyy-MM-dd|HH:mm:ss");

    Map<String,String> params = new HashMap<String, String>();
    params.put("shopId","371");

// params.put("advertAreaId","1");
// params.put("mode","iisue");
// params.put("call","shopService.qryAdvertList");
// params.put("params","{\"advertAreaId\":\"1\",\"shopId\":\"371\"}\n");
// params.put("version","1.0.0");

    String strUrlPath = "http://192.168.31.177:8081" + "DataTime=" + strNowDateTime;
    String strResult = HttpUtils.submitPostData(strUrlPath,params,"utf-8");
    result.setText(strResult);
}
private String getNowDateTime(String strFormat){
    if (strFormat == ""){
        strFormat = "yyyy-MM-dd HH:mm:ss";
    }
    Date now = new Date();
    SimpleDateFormat dateFormat = new SimpleDateFormat(strFormat);
    return dateFormat.format(now);
}

}