public class BackgroundWorker extends AsyncTask<String,String,String> {
   Context context;
   AlertDialog alertDialog;
   BackgroundWorker(Context ctx)
    {
     context =ctx;
    }

@Override
protected String doInBackground(String... params) {
    String type=params[0];

    String login_url="http://server27.000webhost.com/login.php";

    if(type.equals("login"))
    {

        try {
            String user_name = params[1];
            String password = params[2];
            URL url = new URL(login_url);
            HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            OutputStream outputStream = httpURLConnection.getOutputStream();
            BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
            String post_data = URLEncoder.encode("user_name","UTF-8")+"="+URLEncoder.encode(user_name,"UTF-8")+"&"
                    +URLEncoder.encode("password","UTF-8")+"="+URLEncoder.encode(password,"UTF-8");
            Log.i("ok", "doInBackground username: " + user_name);
            Log.i("ok", "doInBackground PSWRD: " + password);
            bufferedWriter.write(post_data);
            bufferedWriter.flush();
            bufferedWriter.close();
            outputStream.close();
            InputStream inputStream = httpURLConnection.getInputStream();
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
            String result="";
            String line="";
            while((line = bufferedReader.readLine())!= null) {

                result += line;
            }
            bufferedReader.close();
            inputStream.close();
            httpURLConnection.disconnect();
            return result;
        } catch (MalformedURLException e) {
            Log.i("ok", "doInBackground: erroprrr hai bhaeeee");
            Log.e("ok", e.getMessage(), e);
            e.printStackTrace();
        } catch (IOException e) {
            Log.i("ok", "doInBackground: erroprrr hai bhaeeee 22222");
            Log.e("ok", e.getMessage(), e);
            e.printStackTrace();
        }
    }
    return null;
}
@Override
protected void onPreExecute() {
   alertDialog=new AlertDialog.Builder(context).create();
    alertDialog.setTitle("Login Status");

}

@Override
protected void onPostExecute(String Result) {
    Log.i("ok", "Result " + Result);
    alertDialog.setMessage(Result);
    alertDialog.show();

}

public class CheckConn extends AppCompatActivity {
EditText user;
EditText pass;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.check_conn);


user = (EditText) findViewById(R.id.et_u);
pass = (EditText) findViewById(R.id.et_p);
Button press = (Button) findViewById(R.id.btn_login);
press.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        onLogin();
    }
   });
}

public void onLogin()
{
String username= user.getText().toString();
String password=pass.getText().toString();
String type="login";

BackgroundWorker backgroundWorker=new BackgroundWorker(this);

backgroundWorker.execute(type,username,password);
   }
}

$mysql_usernmae="root";
 $mysql_password="*****";
 $db="map";
 $db= new mysqli('localhost',$mysql_usernmae,$mysql_password,$db);
  ?>

<?php
 require "connection.php";
 $user_name=$_POST["user_name"];
  $user_pass=$_POST["password"];
  $mysql_qry="select * from user_info where user_name like
 '$user_name' and user_password like 'user_pass';";
  $result=mysqli_query($db,$mysql_qry);
  if (mysqli_num_rows($result) > 0)
  {
  echo "login Success";
  }
  else
 {
 echo "failed";
 }
 ?>