/**
* 集合的去重
* @param list1 要保留的集合
* @param list2
* @return
*/
public static List<String> removeAll(List<String> list1,List<String> list2){
LinkedList<String> result = new LinkedList<>(list1);
HashSet<String> set = new HashSet<>(list2);
Iterator<String> itor = result.iterator();
while(itor.hasNext()){
if(set.contains(itor.next())){
itor.remove();
}
}
return result;
}