Need Help - Sorting an ArrayList of Strings

[K Bala]

I have an ArrayList of Strings like this

"132 8"
"132 12"
"132 4"
"132 19"

When I sort it using Collections.sort() method, I get

132 12
132 19
132 4
132 8

I want the ArrayList to be sorted like this

132 4
132 8
132 12
132 19

How can I achieve this? Please help

[Rob Spoor]

You'll need a custom comparator that, when comparing, splits the strings based on the space (hint: String.split), then converts the array elements to Integers (or Longs, depending on the length), and then compares these.

As for the comparing of the Integers, you'll need to compare the separate parts. Something like this:

// assumption: no null elements in the array
Integer[] array1;
Integer[] array2;
int index = 0;
while (index < array1.length && index < array2.length)
{
    int diff = array1[i].compareTo(array2[i]);
    if (diff != 0)
    {
        return diff;
    }
}
// so far the elements are equal; check on length
if (array1.length < array2.length)
{
    return -1;
}
if (array2.length > array1.length)
{
    return 1;
}
// same length, same elements: the same
return 0;