Anonymous Inner Class Flavour 1 Question

[Arjun Reddy]

Hi all,

I have a question about Anonymous Inner Classes. I am basically trying to create an Anonymous Inner class for Outer class (In Kathy Sierra book, they have created anonymous inner class for some other class and not for outer class). I am pasting the code below. I am getting an exception from the lines which I have commented. Can someone please tell me why am getting the exception when I try to run this program?

  package com.gss.flavour1;
 
public class Outer {
 
void display()
{
System.out.println("Outer class display");
}

Outer obj = new Outer(){
void display()
{
System.out.println("Inner class display");

}
};


void test()
{
obj.display();
}

public static void main(String[] args) {

//Outer object = new Outer();
//object.test();
System.out.println("Just printin");

}
 
}
  

Exception I got is:
Exception in thread "main" java.lang.StackOverflowError

Thanks.
[ September 19, 2008: Message edited by: Arjun Reddy ]

[Seema Gaurav]

Hi Arjun,
I think this is what is happening:

I think that the problem is that the constructor is recursively calling itself here.
When main() starts, it goes ahead and creates the Outer object,but while creating it, it sees that there is an instance variable 'obj' that's created from an anonymous class(a subclass) of Outer. So the Outer() constructor will be called again which amounts to a
StackOverFlowError.

Correct me,if I'm wrong!
Seema

[Arjun Reddy]

Maybe you are correct Seema.Can ya tell me how I can call the display method then?

Thanks.

[Seema Gaurav]

Arjun, I really don't know if you can do something like that. Forget anonymous classes, even if I were to create an Object of the same class inside my class, it'd run endlessly. IMHO, I think I'd keep them as two separate classes.

Try what happens when you do this -

class A 
{
A()
{
A a=new A();
}
public static void main(String[] args) 
{
A a=new A();
}
}

I hope you get what I'm trying to say. Can somebody explain this better?
Seema

[Seema Gaurav]

Hey,sorry, but this is the code I wanted to post:

class A 
{
        A a;
A()
{
 a=new A();
}
public static void main(String[] args) 
{
A a=new A();
}
}

Thanks,
Seema

[Steve S.]

You are stuck in an endless loop. Turn your debugger on and see, the Outer obj.. line gets called over and over again.

[Ankit Garg]

package com.gss.flavour1;
 
public class Outer
{
void display()
{
System.out.println("Outer class display");
}

static Outer obj = new Outer(){
void display()
{
System.out.println("Inner class display");

}
};


void test()
{
obj.display();
}

public static void main(String[] args) {

Outer object = new Outer();
object.test();
System.out.println("Just printin");

}
 
}

And Seema you can use this button to edit your post if you write something wrong...

[ September 19, 2008: Message edited by: Ankit Garg ]

[Arjun Reddy]

Thanks Guys...

[Seema Gaurav]

Thanks Ankit, didn't know that...
Seema