`.`分割后字典排序

Sort.java

	List<String> arr = Arrays.asList ("a.b.c", "a.b", "a.ab", "c");
	arr.sort ((o1, o2) -> {
		String[] spilt1 = o1.split ("\\.");
		String[] spilt2 = o2.split ("\\.");
		int compare = 0;
		for (int i = 0; i < spilt1.length && i < spilt2.length; i++) {
			compare = spilt1[i].compareTo (spilt2[i]);
			if (compare != 0)
				break;
		}
		compare = (compare == 0) ? Integer.compare (spilt1.length, spilt2.length) : compare;
		return compare;
	});