Check question using HashSet

Question

I am trying to stop the same question from appearing again on the screen ones it has been answered. like store the last question and then check to see if it's not already been asked. . just want to no with what i have up to now am i on the right tracks or not? been told to use HashSet also.
code:
// the question being shown
String question=questionLabel.getText();
// gets the new question
String newQuestion=ClientCommunication.getRandomQuestion();
// where trying to check the the newQuestion is not already been asked
try {
HashSet questionhash = new HashSet();
questionhash.add(question);
System.out.println(questionhash);
if(newQuestion.equals(questionhash))
newQuestion=ClientCommunication.getRandomQuestion();
} catch (Exception e) {
System.out.println("Error: " + e); }
// shows the new question
questionLabel.setText(newQuestion);
answerField.setText("");
any helpful hints / tips i would be grateful
cheers chris

Answer 1

That can be fixed a little:
try {
  HashSet questionhash = new HashSet();
  String question = null;
  do {
    question = ClientCommunication.getRandomQuestion();
  } while (! questionhash.add(question) )
  System.out.println(questionhash);
  questionLabel.setText(question);
  answerField.setText("");
} catch (Exception e) { //catch specific exceptions rather than Exception e...
  e.printStackTrace();;
}My preference would be to make the ClientCommunication class create a Stack with random order of questions, each time a guestion is asked for pop it out of the Stack, add it to a 'read' List and return it. Return null when you reach the end of the Stack (as a signal) and then reshuffle the List and fill the Stack again. This way, once-only and random order can be controlled at the source, which IMHO is better...