I am extending ArrayList to create a custom ArrayList that can be modified using normal ArrayList methods while iterating over it. For this I am also creating an Iterator.
public class SynchronizedList<E> extends ArrayList<E>
{
// Fields here
//Constructors and methods here
public class SynchronizedListIterator<E> implements Iterator<E>
{
public int index;
private E current;
public boolean hasNext()
{
synchronized (/* reference to enclosing List object */) {
//code goes here
}
return false;
}
//more methods here
}
}
During my hasNext() and next() methods, I need to make sure the list is not modified (it can be modified at any other time). Hence I need to refer to my enclosing type in my synchronized() block.