java8实现List中对象属性的去重方法

List<UserCar> list1 = new ArrayList();

UserCar userCar = new UserCar();

userCar.setId( 1 );

userCar.setCarNo( "AA" );

list1.add(userCar);

UserCar userCar1 = new UserCar();

userCar1.setId( 2 );

userCar1.setCarNo( "AA" );

list1.add(userCar1);

Person p1 = new Person( 1 , "11" );

Person p2 = new Person( 1 , "22" );

Person p3 = new Person( 2 , "11" );

List<Person> persons = Arrays.asList(p1, p2, p3);

private List<UserCar> removeDupliByRecordId(List<UserCar> userCars) {

Set<UserCar> personSet = new TreeSet<UserCar>((o1, o2) ->o1.getRecordId()测试数据pareTo(o2.getRecordId()));

personSet.addAll(userCars);

return new ArrayList<UserCar>(personSet);

}

public TreeSet(Comparator<? super E> comparator) {

  this ( new TreeMap<>(comparator));

  }

List<Person> unique = persons.stream().collect(

  Collectors.collectingAndThen(

   Collectors.toCollection(() -> new TreeSet<>(Comparator测试数据paring(Person::getName))), ArrayList:: new )

);

unique.forEach(p -> System.out.println(p));

List<String> names = new ArrayList<>(); //用来临时存储person的id

List<Person> personList = persons.stream().filter( // 过滤去重

  v -> {

   boolean flag = !names.contains(v.getName());

   names.add(v.getName());

   return flag;

  }

).collect(Collectors.toList());

//根据id去重

examRoomModelLists = examRoomModelLists.stream().collect(Collectors.collectingAndThen(Collectors.toCollection(

         // 利用 TreeSet 的排序去重构造函数来达到去重元素的目的

         // 根据firstName去重

         () -> new TreeSet<>(Comparator测试数据paring(ExamRoomModel::getId))), ArrayList:: new ));

em.setNoLoginExamineeCount((examinee.stream().map(ExamineeEntity::getStudentExamState).filter(x ->

x == 0 ).collect(Collectors.toList())).size());

       }

List<ExamRoomModel> filterList = examRoomModelLists.stream().filter(ExamRoomModel ->

!Objects.equals(ExamRoomModel.getExamRoomStudentCount(), 0 )).collect(Collectors.toList());