public class DBConnect extends AsyncTask<String, Void, Connection>
    {
        private Context ctx;
        SharedPreferences prefs;
        Connection conn;
        String ipValue;
        public DBConnect(Context ctx)
        {
            this.ctx=ctx;
        }
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            //get sharedPreferences here
            prefs = ctx.getSharedPreferences("DoorSystem_SHPREF",
                    Context.MODE_PRIVATE);
            ipValue=prefs.getString("IP_VALUE",null);
        }
        @Override
        protected Connection doInBackground(String... params) {


            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                    .permitAll().build();
            StrictMode.setThreadPolicy(policy);
            String ConnURL = null;
            try {

                Class.forName("net.sourceforge.jtds.jdbc.Driver");
                ConnURL = "jdbc:jtds:sqlserver://" + ipValue + ":1433/doors;user=sam123;password=111";
                conn = DriverManager.getConnection(ConnURL);
            } catch (Exception se) {
                se.printStackTrace();
            }

            return conn;
        }
    }

public void logIn(View view)
    {
        Toast.makeText(getApplicationContext(),ipValue,Toast.LENGTH_LONG).show();
        try {
            DBConnect dbConnect = new DBConnect(getApplicationContext());
            Connection conn=dbConnect.execute().get();
            LogInStatement="select count(*) from users where username=? AND password=?";
            preparedStatement=conn.prepareStatement(LogInStatement);
            preparedStatement.setString(1,userNameEditText.getText().toString());
            preparedStatement.setString(2,passwordEditText.getText().toString());
            ResultSet rs = preparedStatement.executeQuery();
            while (rs.next()) {
                count = rs.getInt(1);
            }
            if (count != 0) {
                Intent userScreenIntent = new Intent(this, UserScreen.class);
                startActivity(userScreenIntent);
            } else {
                Toast.makeText(getApplicationContext(), "بيانات الدخول غير صحيحة", Toast.LENGTH_LONG).show();
            }
        }
        catch(Exception e)
        {
           e.printStackTrace();
        }
    }