Asynctask: pass two or more values from doInBackground to onPostExecute

Question

I have an Asynctask which retrieves two int vaules and i want to pass them to onPostExecute to show them on the view.
Here is my code:

    public class Q         


        

Answer 1

Have you tried making those two ints members of QueryServer?

onPostExecute() doesn't run until after doInBackground() is finished, so there shouldn't be any threading issues.

Answer 2

The most straightforward way is simply declare a small container object with the fields you want to return, then return an instance of that from doInBackground:

private class QueryResult {
    int onlinePlayers;
    int maxPlayers;

    public QueryResult( int onlinePlayers, int maxPlayers ) {
        this.onlinePlayers = onlinePlayers;
        this.maxPlayers = maxPlayers;
    }
}

protected QueryResult doInBackground(String... serverAddress) {
    // ...

    return new QueryResult( onlinePlayers, maxPlayers );
}

Answer 3

public class QueryServer extends AsyncTask <String, Void, Integer>{...}

Replace the Integer generic param to ArrayList<Integer> or to Integer[]

This way your doInBackground() will look like this:

protected Integer[] doInBackground(String... serverAddress) 
{
    ...do what you need to do...
    //Then create an array, fill with data, and return.
    Integer[] arr = new Integer[10];
    for(int i=0; i<10; i++)
        arr[i] = i; //just an example
    return arr;
}

And the in your onPostExecute()

protected void onPostExecute(Integer [] Onlineplayers)
{
    //Do whatever you want with your array
}

Answer 4

You can define a Wrapper class that holds two integers:

public class Wrapper
{
    public int onlinePlayers;
    public int maxPlayers;
}

and use it in place of Integer:

public class QueryServer extends AsyncTask<String, Void, Wrapper> { 

    protected Wrapper doInBackground(String... serverAddress) {
        Log.d("QueryServer", ""+serverAddress[0]);
        MCQuery mcQuery = new MCQuery("" + serverAddress[0] ,25565);
        QueryResponse response = mcQuery.basicStat();

        int onlinePlayers = response.getOnlinePlayers(); //first vaule
        int maxPlayers = response.getMaxPlayers();  //second vaule

        Log.d("MCQuery", "" + onlinePlayers + " onlinePlayers");
        Wrapper w = new Wrapper();
        w.onlinePlayers = onlinePlayers;
        w.maxPlayers = maxPlayers;
        return w;

    }

    protected void onPostExecute(Wrapper w){

        TextView onlinePlayersView = (TextView) findViewById(R.id.online_players);

        onlinePlayersView.setText(""+w.onlinePlayers+"/"+ w.maxPlayers); //i need to pass Maxplayers to use it here


    }

Answer 5

Generally speaking, replace Integer with ArrayList of Objects. with this array, you can pass any collection of any types. but obviously, the downside is you should cast the members and you should know all the types...