Java – sort F: selectitems list based on tags

I have a list of selectitem values and tags The data is obtained from the database. The selectitem list has the following values:

<1,100-500>
<2,1000-1500>
<3,500-1000>

Here, 1, 2 and 3 are the values of the selectitem list, and '100-500', '1000-1500' and '500-1000' are the labels respectively As you can see, the list is sorted by label However, my requirement is that the list should be displayed in the drop-down list as follows:

100-500
500-1000
1000-1500

Can someone suggest a solution?

Solution

If you cannot modify the code that gets the selectitem instance from the DB to sort according to your preference, you must sort them yourself:

// this gets you a list which is not sorted as you would like
List<SelectItem> list = getMasterValues("Staff Range");

// you need to sort the list before displaying it. 
// To sort the list,you need a Comparator which will tell the sorting
// algorithm how to order the items
Comparator<SelectItem> comparator = new Comparator<SelectItem>() {
    @Override
    public int compare(SelectItem s1,SelectItem s2) {
        // the items must be compared based on their value (assuming String or Integer value here)
        return s1.getValue().compareTo(s2.getValue());
    }
};

// Now that you have the comparator,sort the list using it :
Collections.sort(list,comparator);

// and Now iterate over the list to display it :
for (SelectItem item : list) {
    System.out.println("value = " + item.getValue() + "; label = " + item.getLabel());
}