import java.util.ArrayList; import java.util.HashSet; import java.util.List; import java.util.Set; public class zuoye1 { public static void main(String[] args) { List<String> list = new ArrayList<>(); list.add("a"); list.add("f"); list.add("b"); list.add("c"); list.add("a"); list.add("d"); System.out.println(list); list = removeSame(list); System.out.println(list); } private static List<String> removeSame(List<String> list) { Set<String> set = new HashSet<>(); set.addAll(list); List<String> listSingle = new ArrayList<>(); for(String s : set){ listSingle.add(s); } return listSingle; } }