Java FX Help

Drackeo · May 12, 2015

Hey for a class that im in i have to create a program that plays Blackjack or 21, whatever you call it. And i have no idea on how to initialize the deck on a button click and how to make it shuffle said deck on a button press. Lovely project concidering we have only been at this for like 3 classes....

Help pllease. Ill post what i have below!

ProjectBlackJack.txt

madknight3 · May 12, 2015

I'm not sure which part you're having trouble with so I'll cover two things

1. Initializing a class and calling a method

// Using the following classpublic class Example {    public Example() {}    public void someMethod() {}}// You initialize the class like soExample ex = new Example();// You call a method in the class like soex.someMethod();

2. Running code in a button click

public void start(Stage primaryStage) throws Exception{    // ...    Button btn1 = new Button("...");    btn1.setOnAction((clicked) -> {        // Code to run goes here between the curly brackets        Example ex = new Example();        ex.someMethod();     });    // ...}

Also note that you can define the object outside the click event and still use it. You'll need to do this if using the object outside of the button click event.

private Example ex;public void start(Stage primaryStage) throws Exception{    // ...    ex = new Example();    Button btn1 = new Button("...");    btn1.setOnAction((clicked) -> {        ex.someMethod()    });    // ...}

With that you should be able to figure out how to get the button click to create and shuffle the deck.

Drackeo · May 12, 2015

So using what you gave me i ended up getting this

btn1.setOnAction((clicked) -> {

for(int i = 0; i<this.deck.length; i++){

int j = (int)(Math.random()*this.deck.length);

int temp = this.deck;

this.deck = this.deck[j];

this.deck[j] = temp;

}

this.next_card = 0;

});

and also able to intitalize a deck at the begining.

But when ever i try and use that button im getting a massive string of error messages. idk why

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException

at ProjectBlakcJack.lambda$2(ProjectBlakcJack.java:53)

at ProjectBlakcJack$$Lambda$72/1962811315.handle(Unknown Source)

at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)

at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)

at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)

at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)

at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)

at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)

at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)

at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)

at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)

at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)

at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)

at javafx.event.Event.fireEvent(Unknown Source)

at javafx.scene.Node.fireEvent(Unknown Source)

at javafx.scene.control.Button.fire(Unknown Source)

at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(Unknown Source)

at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(Unknown Source)

at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)