spring删除父节点及其所有子节点

service

public void deleteCategoriesById(Long id,Long pid) {

        //获取对象
        Category category1 = this.categoryMapper.selectByPrimaryKey(id);

        //创建子对象的id的列表
        List<Long> sons = new ArrayList<>();

        //创建中间列表
        List<Long> temp = new ArrayList<>();

            //判断是否是父节点
        if (category1.getIsParent()) {
            //若是父节点
            Example example = new Example(Category.class);
            Example.Criteria criteria = example.createCriteria();
            criteria.andEqualTo("parentId", id);

            //删除本节点
            this.categoryMapper.deleteByPrimaryKey(id);

            while (true) {
                //获取所有子对象列表
                List<Category> categories = this.categoryMapper.selectByExample(example);

                //遍历子节点列表
                for (Category category2 : categories) {
                    //判断子节点是否为父节点
                    if (category2.getIsParent()) {
                        temp.add(category2.getId());
                    }
                    //将所有需要删除的id放入sons中
                    sons.add(category2.getId());
                }
//				此处如果使用增强for循环，会报ConcurrentModificationException，
//              因为增强for循环也是通过Iterator实现的，使用List的remove方法会与Iterator产生冲突
//                for (Long son:sons){
//                    this.categoryMapper.deleteByPrimaryKey(son);
//                    sons.remove(son);
//                }
                //遍历，获取子对象id
                Iterator<Long> iterator = sons.iterator();
                while (iterator.hasNext()) {
                    Long son = iterator.next();
                    this.categoryMapper.deleteByPrimaryKey(son);
                    iterator.remove();
                }

                //如果子节点还有子节点
                if (temp.size() > 0) {
                    sons=temp;
                    temp = new CopyOnWriteArrayList<Long>();
                } else {
                    break;
                }

            }


        }

        //若不是父节点,判断其父节点是否只剩一个子，如果只剩一个，则将父节点isparent改为false
        this.categoryMapper.deleteByPrimaryKey(id);
        Category category3 = new Category();
        category3.setParentId(pid);
        List<Category> list = this.categoryMapper.select(category3);
        //list.forEach(System.out::println);
        if (list.isEmpty()){

            Category category = new Category();
            category.setId(pid);
            category.setIsParent(false);
            this.categoryMapper.updateByPrimaryKeySelective(category);

        }

    }

pojo

public class Category {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    private Long parentId;
    private Boolean isParent;
    private Integer sort;

//get、set
}

代码比较冗余，之后再改

标签：Category,删除,spring,Long,id,categoryMapper,sons,节点
来源： https://blog.csdn.net/madaooadam/article/details/100108686