集合子列表，集合列表,public class

集合子列表，集合列表,public class

public class CollectionUtils {   public static <T> ArrayList<T> getSubList(List<T> l, int offset, int length) {      if (offset >= l.size())         return new ArrayList<T>(0);      if (length < 0)         return new ArrayList<T>(0);      ArrayList<T> sl = new ArrayList<T>(length);      int upper = offset + length;      int bound = upper < l.size() ? upper : l.size();      for (int i = offset; i < bound; i++)         sl.add(l.get(i));      return sl;   }}