我的安卓应用程序没有收到任何响应从服务器而发送json

我试图使用php webservice从mysql发送Json数据到android应用程序但是我没有从服务器得到任何响应，我确信从我的路径到webservice。这是我的PHP代码

<?php
    header("Content-Type: application/json;charset=utf-8");
    $host = 'localhost';
    $uname = 'root';
    $pwd = '';
    $db = 'test';
    $flag = array();
    $con = mysqli_connect($host, $uname, $pwd,$db) or die('Connection Failed');
    mysqli_query($con,"SET NAME 'utf8'");
    mysqli_query($con,'SET CHARACTER SET utf8');
    $query = mysqli_query($con,"SELECT BRANCH,SUBSCRIBER,REGION,LOCATION_NO,ORG,TYPE,FOR_MONTH,PHASE_TYPE,NAME,KW_COUNTER_NO
         ,KW_LAST_READ,MULTIPLY_FACTOR,KV_COUNTER_NO,KV_LAST_READ,KV_MULTIPLY_FACTOR,KW_OPSERVER_1_LAST_READ,OP_MULTIPLY_FACTOR,
         KW_OPSERVER_2_LAST_READ,KW_OPSERVER_3_LAST_READ,NOTES,Is_Auto_Pay,Counter_Read_Digit,M_B,AMBIR,IS_NEW_COUNTER FROM last_reads");
    while($row = mysqli_fetch_array($query)) {
        $flag[] = $row;
    }
    echo json_encode($flag,JSON_UNESCAPED_UNICODE);
    mysqli_close($con);
?>

这是我的android代码

private void webservice() {
        // TODO Auto-generated method stub
        new TheTask().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
    }
class TheTask extends AsyncTask<String,String,String>
    {
        @Override
        protected void onPostExecute(String result) {
            pb.setVisibility(View.GONE);
            Toast.makeText(getApplicationContext(), "command sent", Toast.LENGTH_LONG).show();
            resumeWebService();
        }
        protected void onProgressUpdate(Integer... progress){
            pb.setProgress(progress[0]);
        }
        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
        }
        @Override
        protected String doInBackground(String... params) {
            try {
                Log.d("1","1");
                HttpClient httpClient = new DefaultHttpClient();
                Log.d("1", "2");
                HttpPost httpPost = new HttpPost(ip);
                Log.d("1","3");
                HttpResponse response = httpClient.execute(httpPost);
                Log.d("1","4");
                HttpEntity entity = response.getEntity();
                Log.d("","length"+response.getEntity().getContentLength()); //return 0 !
                is = entity.getContent();
                Log.d("1","5");
            }
            catch (Exception e) {
                Log.e("Webservice 1", e.toString());
            }
            return "";
        }