Android Studio Login Page with php coect to localhost how start other activitie java if username and password is correct

I create new project in Android Studio. Did login Page. Did php file to check if useame and password is Correct.

<?php
require "co.php";
$user_name = $_POST["user_name"];
$user_pass = $_POST["password"];
$mysql_qry = "select * from employee_data where useame like '$user_name'and password like '$user_pass'";
$result = mysqli_query($co ,$mysql_qry);
if(mysqli_num_rows($result) > 0) {

echo"login success";

}else {

echo "login not success";
}
?>

My java Code in Android Studio

public class MainActivity extends AppCompatActivity {
EditText etnomedeutilizador, etpassword;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    etnomedeutilizador = (EditText)findViewById(R.id.etnomedeutilizador);
    etpassword = (EditText)findViewById(R.id.etpassword);
}
public void botaologinonClick(View view) {
    String useame = etnomedeutilizador.getText().toString();
    String password = etpassword.getText().toString();
    String type = "login";
    BackGroundWorker backGroundWorker = new BackGroundWorker(this);
    backGroundWorker.execute(type, useame, password);
    System.err.println("aspas");

My java (BackGroundWorker) code is this

public class BackGroundWorker extends AsyncTask<String,Void,String> {
Context context;
AlertDialog alertDialog;
BackGroundWorker (Context ctx) {
    context = ctx;
}
@Override
protected String doInBackground(String... params) {
    String type = params[0];
    String login_url = "http://192.168.1.79/login.php";
          if(type.equals("login")) {
        try {
            String user_name = params[1];
            String password = params[2];
            URL url = new URL(login_url);
            HttpURLCoection httpURLCoection = (HttpURLCoection) url.openCoection();
            httpURLCoection.setRequestMethod("POST");
            httpURLCoection.setDoOutput(true);
            httpURLCoection.setDoInput(true);
            OutputStream outputStream = httpURLCoection.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");
            String user = URLEncoder.encode(user_name, "UTF-8");//guarda o nome de utilizador introduzido
            String pass = URLEncoder.encode(password, "UTF-8");//guarda a pass introduzido
            System.err.println("------------------------------------------");
             /*/  if(user.equals("Nome de Utilizador")){
                   if(pass.equals("Password")) {
                       System.err.println("Entrou no if");
                       startActivity(new Intent(this, Pagina1.class));}

/*/

            bufferedWriter.write(post_data);
            bufferedWriter.flush();
            bufferedWriter.close();
            outputStream.close();
            InputStream inputStream = httpURLCoection.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();
            httpURLCoection.discoect();
            retu result;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

Question: If my useame and password are correct with my DataBase(localhost) i want to start new activitie in my Android Studio after message shown from php (Login Success). Login Success if useame and/or password wrong show message from php (login not success). Wrong Password

To me more specified, application stays in "Login Success" message from php and i want it to start new activitie java in my Android after that.