在写商品分类多级列表时,
问题出在Controller层的第12,13,14行
12行我打印对象是存在的,但是13行赋值时一直为空
public Map<String,Object> findAll() {
Map<String,Object> map = new HashMap<>();
try {
Map<String,Object> map1 = new HashMap<>();
List<Category> categorys =categoryService.findAll();
//存放所有一级目录
List<CategoryTwo> categoryTwos = new ArrayList();
//找出父级目录
for(Category category : categorys){
if(category.getCat_pid() == 0){
System.out.println(category);
CategoryTwo categoryTwo = new CategoryTwo(category);
categoryTwos.add(categoryTwo);//存入一级目录集合中
System.out.println(categoryTwos);
}
}
map1.put("msg","获取成功");
map1.put("status",200);
map.put("meta",map1);
}catch (Exception e){
e.printStackTrace();
}
return map;
}
运行结果
父级实体对象
public class Category {
private Integer cat_id;
private String cat_name;
private Integer cat_pid;
private Integer cat_level;
private String cat_icon;
public List children;
}
二级实体对象
public class CategoryTwo extends Category{
private List<CategoryTwo> categorieTwos;
public CategoryTwo(Category category){
super(category.getCat_id(),category.getCat_name(),category.getCat_pid(),
category.getCat_level(),category.getCat_icon(),category.getChildren());
}
}
数据库