Ich möchte die Ausnahme eines Threads in doInBackground abfangen und die Fehlermeldung in onPostExcecute ausgeben. Das Problem ist, dass ich das Throwable-Objekt nicht in onPostExecute habe. Wie mancatch Ausnahme in Nicht-UI-Thread undGibt die Fehlermeldung im UI-Thread aus?

public class TestTask extends AsyncTask<Void, Void, List<String>> {

    @Override
    protected List<String> doInBackground(final Void... params) {
        try {
            ...
            return listOfString;
        } catch(SomeCustomException e) {
            ...
            return null;
        }       
    }

    @Override
    protected void onPostExecute(final List<String> result) {
        if(result == null) {
            // print the error of the Throwable "e".
            // The problem is I don't have the Throwable object here! So I can't check the type of exception.
        }

    }
}

Update nach Aruns Antwort:

Dies ist meine AsyncTask-Wrapper-Klasse. Es beabsichtigt, Exception in doInBackground zu behandeln, aber ich kann keine gute Lösung dafür finden.

public abstract class AbstractWorkerTask<Params, Progress, Result>
extends AsyncTask<Params, Progress, Result>
implements Workable {
    protected OnPreExecuteListener onPreExecuteListener;
    protected OnPostExecuteListener<Result> onPostExecuteListener;
    protected ExceptionHappenedListener exceptionHappendedListener;
    private boolean working;

    @Override
    protected void onPreExecute() {
        if (onPreExecuteListener != null) {
            onPreExecuteListener.onPreExecute();
        }
        working = true;
    }

    @Override
    protected void onPostExecute(final Result result) {
        working = false;
        if(/* .........*/ ) {
            exceptionHappendedListener.exceptionHappended(e);
        }
        if (onPostExecuteListener != null) {
            onPostExecuteListener.onPostExecute(result);
        }
    }

    @Override
    public boolean isWorking() {
        return working;
    }

    public void setOnPreExecuteListener(final OnPreExecuteListener onPreExecuteListener) {
        this.onPreExecuteListener = onPreExecuteListener;
    }

    public void setOnPostExecuteListener(final OnPostExecuteListener<Result> onPostExecuteListener) {
        this.onPostExecuteListener = onPostExecuteListener;
    }

    public void setExceptionHappendedListener(final ExceptionHappenedListener exceptionHappendedListener) {
        this.exceptionHappendedListener = exceptionHappendedListener;
    }

    public interface OnPreExecuteListener {
        void onPreExecute();
    }

    public interface OnPostExecuteListener<Result> {
        void onPostExecute(final Result result);
    }

    public interface ExceptionHappenedListener {
        void exceptionHappended(Exception e);
    }
}