how to check if an object already exists

[oll3i]

how to check if an object already exists and return reference to that object

[oll3i]

nazwa is a string and yes i used equals(nazwa.eq uals(k.nazwa)) in the equals method

[oll3i]

but now what to do with the buttons problem

[JosAH]

but now what to do with the buttons problem

I don't know; for starters: are both ActionListeners registered with those Buttons
using the same List? Add a lot of System.out.prin tln(...) debug statements and
see what happens.

kind regards,

Jos

ps. does your equals() and hashCode() methods work correctly now?

[oll3i]

thank u a lot lot lot yes they do :)

[oll3i]

i did use lots of System.out.prin t() but the prob is that what's created by one button is not seen by the other button code and where to look 4 solution of that?

[JosAH]

i did use lots of System.out.prin t() but the prob is that what's created by one button is not seen by the other button code and where to look 4 solution of that?

Are both ActionListeners using the same List in which you added your Klient
objects? Print out both lists everytime you access them and see what's in
them. (they both should be two references to one List).

kind regards,

Jos

ps. a List can print itself quite nicely because it overrides the toString() method.

[oll3i]

i walked through the list and i know that the client is in that list but when i do
int index = klienci.indexOf (klient); it returns false

[JosAH]

i walked through the list and i know that the client is in that list but when i do
int index = klienci.indexOf (klient); it returns false

Can't be, the indexOf() method returns an int; -1 possibly if no object was found.
I think you have to recheck your equals() method and your hashCode() method.
Print out what your equals() method has to say about every comparison.

kind regards,

Jos

[oll3i]

that was with contains sorry so it returns -1

but
Klient k1 = new Klient("Jan",20 0);
Klient k2 = new Klient ("Jan",200);

System.out.prin t(k1.equals(k2) );


returns true


int index = klienci.indexOf (klient);

if(index != -1) {
klient = klienci.get(ind ex);
}
else {
// 'klient' is not in the list 'klienci'
}

[JosAH]

that was with contains sorry so it returns -1

but
Klient k1 = new Klient("Jan",20 0);
Klient k2 = new Klient ("Jan",200);

System.out.prin t(k1.equals(k2) );


returns true


int index = klienci.indexOf (klient);

if(index != -1) {
klient = klienci.get(ind ex);
}
else {
// 'klient' is not in the list 'klienci'
}

You did do a 'klienci.add(k1 )' or 'klienci.add(k2 )' did you? If so, can you show
your equals method just to be sure? Add a System.out.prin tln() to your equals()
method to see if it is called by your List.

kind regards,

Jos