I may have just written an abomination

SetOfLists.java

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Scanner;

public class SetOfLists {
	private static
	<COLL_INNER extends Collection<Integer>, COLL_OUTER extends Collection<COLL_INNER>>
	COLL_OUTER collectionOfCollections(Scanner in, Class<COLL_OUTER> OuterCollection, Class<COLL_INNER> InnerCollection)
	throws InstantiationException, IllegalAccessException {
		System.out.println("Enter one sequence of ints per line to add to the list (space separated; enter to finish line; empty to finish input)");
		
		COLL_OUTER sequences = OuterCollection.newInstance();
		
		String input;
		while (!(input = in.nextLine().trim()).isEmpty()) {
			String[] inputs = input.split("\\s+");
			COLL_INNER curSequence = InnerCollection.newInstance();
			for (String numstr : inputs) {
				int num = Integer.parseInt(numstr);
				curSequence.add(num);
			}
			sequences.add(curSequence);
		}
		
		return sequences;
	}

	public static void main(String[] args) throws InstantiationException, IllegalAccessException {
		Scanner in = new Scanner(System.in);
		System.out.print("[S]etOfLists or [L]istOfSets? ");
		String decision = in.nextLine();
		Collection<Collection<Integer>> outer;
		switch (decision.toCharArray()[0]) {
		case 'S':
			outer = collectionOfCollections(in, HashSet.class, ArrayList.class);
			break;
		case 'L':
			outer = collectionOfCollections(in, ArrayList.class, HashSet.class);
			break;
		default:
			System.out.println("Input not recognised.");
			System.exit(1);
			return;
		}
		
		for (Collection inner : outer) {
			System.out.println(inner.toString());
		}
	}
}