1. 45集 三级分类
接口product/category/list/tree
@Override
public ListlistWhithTree() {
//1.查出所有分类
List entities =baseMapper.selectList(null);
//2.组装成父子树形结构
//2.1找到所有一级分类
List level1Menus = entities.stream().filter(categoryEntity ->
categoryEntity.getParentCid() ==0).map((menu)->{
menu.setChildren(getChildrens(menu,entities));
return menu;
}).sorted((menu1,menu2)->{
return (menu1.getSort() ==null?0:menu1.getSort()) -(menu2.getSort()==null?0:menu2.getSort());
}).collect(Collectors.toList());
return level1Menus;
}
//递归查找所有菜单的子菜单
private ListgetChildrens(CategoryEntity root,List all){
List children = all.stream().filter(categoryEntity -> {
return categoryEntity.getParentCid() ==root.getCatId();
}).map(categoryEntity -> {
//找到子菜单
categoryEntity.setChildren(getChildrens(categoryEntity,all));
return categoryEntity;
}).sorted((menu1,menu2)->{
//菜单的排序
return (menu1.getSort() ==null?0:menu1.getSort()) -(menu2.getSort()==null?0:menu2.getSort());
}).collect(Collectors.toList());
return children;
}
