Unhandled Exception in Poker Game

Question

I've got a multi-part program (2 java files) that are supposed to do two things:

Make a deck of cards (with shuffle, deal, reset)
Create a poker game (making two decks of cards, other stuff...)

There's a barrier I'm hitting because of this Unhandled exception error, and I'm not even sure where it comes from. Error pictured below, source code below that.

Unhandled Exception Error

.

Playing Card Exception Class

class PlayingCardException extends Exception {

    /* Constructor to create a PlayingCardException object */
    PlayingCardException (){
        super ();
    }

    PlayingCardException ( String reason ){
    super ( reason );
    }
}

.

Deck Class /** class Decks represents : n decks of playing cards * Use class Card to construct n * 52 playing cards! * * Do not add new data fields! * Do not modify any methods * You may add private methods */

class Decks {

    /* this is used to keep track of original n*52 cards */
    private List<Card> originalDecks;   

/* this starts with n*52 cards deck from original deck   */
/* it is used to keep track of remaining cards to deal */
/* see reset(): it resets dealDecks to a full deck      */
private List<Card> dealDecks;

/* number of decks in this object */
private int numberDecks;


 /**
 * Constructor: Creates n decks (52 cards each deck) of playing cards in
 *              originalDecks and copy them to dealDecks.
 *              initialize numberDecks=n
 * Note: You need to catch PlayingCardException from Card constructor
 *       Use ArrayList for both originalDecks & dealDecks
 * @throws PlayingCardException 
 */
public Decks(int n) throws PlayingCardException
{
    // implement this method!
    this.originalDecks = new ArrayList<Card>();
    this.dealDecks = new ArrayList<Card>();
    int i, j, k;
    numberDecks = n;
    for (k=0;k<n;k++){
        for (i=1;i<14;i++) 
        {
            for(j=0;j<4;j++) 
            {
                Card orcard = new Card(i,j);
                originalDecks.add(orcard);
                dealDecks.add(orcard);
            }
        }
        }
    }
}

Are you handling the exception in main()? Can you show the main code? — dansalmo, Dec 13 '13 at 05:23
Have a read of http://java.dzone.com/articles/business-logic-domain-objects. It is a common pattern to construct objects from a Factory class, which sets the values. DeckFactory contains the logic you have in your factory to populate Deck with Cards. When you want a new Deck, call DeckFactory.createNewDeck(int n); — Tinman, Dec 13 '13 at 05:36

score 4 · Accepted Answer · edited Dec 13 '13 at 05:34

4

This checked exception is being declared in the constructor for the Decks class.

public Decks(int n) throws PlayingCardException

It is not a good idea to have constructors throw exceptions.

Are you even sure that the code in the constructor will throw this exception?

Try moving this code to another method which can be called in your main code.

edited Dec 13 '13 at 05:34

Tinman

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answered Dec 13 '13 at 05:22

Scary Wombat

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If I remove the "throws PlayingCardException" from the constructor, I get an Unhandled Exception error when trying to make a new card(i,j); – MikaelCMiller Dec 13 '13 at 05:32
1

so maybe catch (and handle) the exception in your constructor - do not re-throw it. – Scary Wombat Dec 13 '13 at 05:34
1

Generally you should handle exceptions in your constructor using a try catch block. – Tinman Dec 13 '13 at 05:34
AHA! Perfect! The try-catch blocks cleared everything up. I was using the suggestion by the IDE to add a "throws PlayingCardException" to the method which is a bad idea. Thanks for that. – MikaelCMiller Dec 13 '13 at 05:40

score 0 · Answer 2 · answered Dec 13 '13 at 05:26

The declaration your constructor is making is that PlayingCardException is a checked exception. This means you must catch it.

Since you're trying to use it as a static field, why bother making it a checked exception at all? Have that extend RuntimeException instead, and if it comes up, you're not absolutely forced to check it any time you want to use it. This way, you can do your static initialization the way you want to.

Unhandled Exception in Poker Game

2 Answers2