Actionlistener for an array of buttons

Question

Hi, I have to make a program which has a lot of buttons, so I decided that they should be generated with two for loops to keep my code clean and tidy. but now I want an Actionlistener added to all of these buttons, so every time one of the buttons is clicked, a specific action happens for that button. Now, I don't think I have to create actionlisteners for all of these buttons, so, can someone give me a little push in the right direction?
maybe this comes in handy, this is just the simple code I use to generate the buttons:
for(int i = 0;i<14;i++) //rijteller
for(int j = 0;j<7;j++) //kolomteller
btReservatie[i][j] = new JButton();
getContentPane().add(btReservatie[i][j]);
btReservatie[i][j].setBounds((x+(j*breedte)), y+(i*hoogte), breedte,hoogte);
}I know some of the variables used don't seem obvious, but that's not the problem here...

Answer 1

Not suprising. I guess i and j are fields in the class. Had they been local variables it would have refused to compile.
The ActionListener you're generating is a separated object, which surives long after the method that created it finishes. The actionPerformed method is called after the whole loop is over, so it's picking up values of i and j which have gone all the way through the loop.
You need the ActionListener to take a copy of i and j when it's created, and use that data when actionPerformed is called. You can either do it as I showed you, or you can use final local variables.
A local class, when it mentions final local variables, implicitly copies them when it's created.
Since you can't change final variables once created you have to copy the loop indicies like:
for(int i = 0; i < 7; i++) {
   final int ii = i;
   for(j = 0; j < 14; j++) {
     final int jj = j;Personally I prefer the approach above.