Thread: Best way to turn a single class into multiple classes

Hello Guys

I'm still a beginner to Java and have written a programme for an assignment which is a GUI with a key pad that registers when you press a buttons on the Keypad. Type a password to unlock the programme and then type a password to unlock the programme.

It's working fine but when it's in the one single class but I need to break it into 2-3 classes but I'm having difficulty doing this successfully.

The class is made up of an arrayList to create the buttons for the Keypad and an arrayList to create the actionsListeners. I keep on running into nullPointerExceptions. Referencing things that have null values!

What are your recommendations to to do this the most efficiently

Thanks

do this the most efficiently

I'd use cut and paste.
Find sections of code that do a single function that is easily given a name, that can take parameters and return a value, cut the code and paste it into a method and replace the cut section with a call to the new method.

Originally Posted by Norm

I'd use cut and paste.
Find sections of code that do a single function that is easily given a name, that can take parameters and return a value, cut the code and paste it into a method and replace the cut section with a call to the new method.

Thanks, that what my problem was I was trying to take too much when I should of been just using small spinets of code and turning them into methods.