Question

In apache common collections what is the difference between:

1. CircularFifoBuffer
2. BoundedFifoBuffer

Ok, the first deletes oldest Entries when full, the other deletes entries in the same order, as the came in. But isn’t it the same?

Answer 1

CircularFifoBuffer extends BoundedFifoBuffer. It only overrides single method – add:

public boolean add(Object element) {
    if (isFull()) {
        remove();
    }
    return super.add(element);
}

So the only difference is that BoundedFifoBuffer throws exception when it’s full and you try to add new element while CircularFifoBuffer removes oldest element.