Set 过滤List里的重复项

  import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Iterator; import java.util.Set; public class listss { public static void main(String[] args){ List list1 = new ArrayList(); list1.add("111"); list1.add("112"); list1.add("114"); List list2 = new ArrayList(); list2.add("111"); list2.add("113"); list2.add("115"); Set set1 = new HashSet(list1); set1.addAll(list2); System.out.println(set1.size()); Iterator iterator = set1.iterator(); while (iterator.hasNext()) { System.out.println(iterator.next().toString()); } List list3 = new ArrayList(set1); System.out.println(list3.size()); } }