Is collection is empty, and all of its elements are empty
import java.util.Collection; import java.util.Iterator; public class Utils { public static <T> boolean isEmpty(Collection<T> c) { if (c == null || c.size() == 0) { return true; } for (Iterator<T> iter = c.iterator(); iter.hasNext();) { if (iter.next() != null) { return false; } } return true; } }