How to sort Alphanumeric String

Question

I have a problem with sorting strings which include integers. If I use the below code I get sorting like: 1some, 2some, 20some, 21some, 3some, some

However I want it

Answer 1

You can do the core of it in one line using regex to extract the numeric part:

Collections.sort(selectedNodes, new Comparator() {
    @Override
    public int compare(DefaultMutableTreeNode o1,
        DefaultMutableTreeNode o2) {
        return Integer.parseInt(o1.getUserObject().toString().replaceAll("\\D", "")) -
            Integer.parseInt(o2.getUserObject().toString().replaceAll("\\D", ""));
    }
});