Is there a class for this?

Question

I'm trying to store a collection of data in which certain elements are removed after they've been present for a certain period of time. Some items live longer than others. What I want is to retrieve these items in roughly the same order every time.
Let's say that I start with 1 2 3 4 5 6 7 8 9 10. Then 4 times out, and 11 comes in. I want retrieve them as 1 2 3 11 5 6 7 8 9 10.
I could write my own class for this, but I'd rather not have to if something like this exists. Any help would be greatly apreciated.

Answer 1

Let's examine your problem carefully
You want to have some data structure that behaves like a list, but insertion order is not at a fixed position, but preferrably at "erased" positions (like a disk using the FAT file system).
java.util.ArrayList will not do the job nicely , nor java.util.LinkedList - you will need to maintain a lot of pointers.
Probably you will have to write a class that borrows the idea from the FAT file system - you have an (almost) fixed-size array representing the data. If you want to remove an item, simply set its reference to "null" in the array.
If you want to insert a new item, you need to find the first (or last - depends on your needs and if it is better to move less or more items on screen) empty slot.
If your data requires more elements than your array size, you must copy the array into a bigger array, and release the older array.