Call Number Ordering/Sorting

example.java

String first  = "BF 637 .C6 A88 vol.24";
String second = "BF 637 .C6 A88x vol.24";
String third  = "BF 637 .C6 A888 vol.24";

//Initialize a CallNumberParser. Since we know we're only parsing LCCallNumbers, we'll keep it simple.
CallNumberParser parser = new CallNumberParser(LCCallNumber.class);
	
//Parse the 3 call numbers and add them to a list (deliberately out of order).
List<CallNumber> list = new ArrayList<>();
list.add(parser.parse(third));
list.add(parser.parse(first));
list.add(parser.parse(second));
	
//Just to prove that call number sorting works correctly, shuffle the list before sorting it according to its
//natural order (which we can do easily, since the CallNumber interface extends Comparable.
Collections.shuffle(list);
Collections.sort(list);
	
for(CallNumber callNumber : list) {
	//Output to show that sorting worked.
	System.out.println(callNumber.getClass().getSimpleName());
	System.out.println("\tNormalized: " + callNumber.toString());
	System.out.println("\tOrderable:  " + callNumber.sortKey());
}

example.out

LCCallNumber
	Normalized: BF 637 .C6 A88 vol.24
	Orderable:  bf000637 c6/ a88/ vol.000024
LCCallNumber
	Normalized: BF 637 .C6 A88x vol.24
	Orderable:  bf000637 c6/ a88/x vol.000024
LCCallNumber
	Normalized: BF 637 .C6 A888 vol.24
	Orderable:  bf000637 c6/ a888/ vol.000024