[java] Singleton pattern
Author
Hallo!
I am programming in java and I have to make sure that only one instance of a class is created. This instance should also be used by other classes. I am trying to use singleton but, it is not working....
This is how i want to get hold of my con:
con c = new con.getTheOne_con();
but it's not correct because when I compile it I get that it can't be resolved to a type
In my con class:
private static con one_con = null;
private con()
{
counter = counter +1;
System.out.println("con created: "+ counter);
}
public static synchronized con getTheOne_con()
{
if(one_con == null)
{
one_con = new con();
}
return one_con;
}
please help.....
Quote:Original post by moth_wannaKnow
Hallo!
I am programming in java and I have to make sure that only one instance of a class is created. This instance should also be used by other classes. I am trying to use singleton but, it is not working....
This is how i want to get hold of my con:
con c = new con.getTheOne_con();
Hint, think about what the emphisized line is TRYING to do...
Author
if it exist it should return it and if it does not it should be created... what am I missing?
I'd say your problem is that "new", you're trying to new a return value which isn't exactly what new is for so that's why it's not working (you can only new types) - and really counterintiutive when you're using Singletons (only one instance is allowed yet you're trying to make a new one?).
So, just remove the new:
con c = con.getTheOne_con();
So, just remove the new:
con c = con.getTheOne_con();
Author
Thanks
It's a little bit to late for me I can't think that clear 3- 4 oclock in the morning...but removed "new" and ofcause it's working now thanks again...
Nu ska jag sova!
It's a little bit to late for me I can't think that clear 3- 4 oclock in the morning...but removed "new" and ofcause it's working now thanks again...
Nu ska jag sova!
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