ManyToOne关系中实体的递归搜索规范

Question

我有以下类定义了两个实体之间的关系，并且我建立了一个似乎适用于基本用例的搜索条件：实体如下（为简洁起见，省略了一些信息！）：

public class Category implements Serializable {
    @Id
    private Long id;
    private String name;
    @ManyToOne
    private Category parent;

    }

//getters ands setters

public class Product implments Serializable {
@Id
private Long id;
private String name;
..
@ManyToOne
private Category category;
}

//getters and setters

我对类别名称的搜索说明如下：

public class ProductSearchSpecification extends BaseSpecification<Product, ProductSearchtRequest> {

@Override
public Specification<Product> getFilter(ProductSearchRequest request) {
    return (root, query, cb) -> {
        query.distinct(true);
        return where(categoryNameContains(request.categoryName))
                .toPredicate(root, query, cb);
    };
}

private Specification<Product> categoryNameContains(String categoryName) {
    return categoryAttributeContains("name", categoryName);
}

private Specification<Product> categoryAttributeContains(String attribute, String value) {
    return (root, query, cb) -> {
        if (value == null) {
            return null;
        }

        Join<Product, Category> category = root.join("category");

        return cb.like(
                cb.lower(category.get(attribute)),
                containsLowerCase(value)
        );
    };
}

This works as expected. I however want to recursively search for all the child categories and get the products as well, ie if I have the following data



{id: 1,name:"Fashion"},
   {id: 20, "name":"Footwear","parentId":1},
   {id: 25, "name":"Sandals","parentId":20}

和一些类别25（凉鞋）的产品，当我使用在属性名称上搜索“鞋类”时，我希望能够使用这些产品。