版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/ITw333/article/details/82831372
在对商品进行分类时,类别表会出现父节点
递归查询本节点的id及孩子节点的id
/**
* 递归查询本节点的id及孩子节点的id
* @param categoryId
* @return
*/
public ServerResponse<List<Integer>> selectCategoryAndChildrenById(Integer categoryId){
Set<Category> categorySet = Sets.newHashSet();
findChildCategory(categorySet,categoryId);
List<Integer> categoryIdList = Lists.newArrayList();
if(categoryId != null){
for(Category categoryItem : categorySet){
categoryIdList.add(categoryItem.getId());
}
}
return ServerResponse.createBySuccess(categoryIdList);
}
//递归算法,算出子节点
private Set<Category> findChildCategory(Set<Category> categorySet ,Integer categoryId){
Category category = categoryMapper.selectByPrimaryKey(categoryId);
if(category != null){
categorySet.add(category);
}
//查找子节点,递归算法一定要有一个退出的条件
List<Category> categoryList = categoryMapper.selectCategoryChildrenByParentId(categoryId);
for(Category categoryItem : categoryList){
findChildCategory(categorySet,categoryItem.getId());
}
return categorySet;
}