List 集合的进阶使用

List 集合的进阶使用

用foreach的lambda表达式迭代List<User>集合

 public void lambdaUserList(List<User> list){
        list.forEach(obj -> System.out.println(obj));
    }

使用迭代器的删除方法

public void IteratorRemoveList(List<Integer> list){
        Iterator<Integer> integerIterator=list.iterator();
        while(integerIterator.hasNext()){
           Integer returnInteger=integerIterator.next();
            if (returnInteger==1){
                integerIterator.remove();
            }
        }
      forEachIntegerList(list);
    }

用Iterator迭代器的forEachRemaining方法运用lambda表达式迭代List<User>集合

public void IteratorlambdaUserList(List<User> list){
        Iterator<User> iterator=list.iterator();
        iterator.forEachRemaining(Object-> System.out.println("迭代集合元素"+Object));
    }

使用排序器对List集合进行排序

  public void compareUserList(List<User> list){
    Collections.sort(list,new Comparator<User>(){
        @Override
        public int compare(User user1, User user2) {
            if (user1.getId() > user2.getId()){
                return -1;
            }else if (user1.getId() == user2.getId()){
                return 0;
            }
            return 1;
        }
    });
    for (User user:list) {
        System.out.println(user.toString());
    }
}