Question

我试图在前端使用Angular设置Spring MVC Rest API。我绝对是这两种技术的初学者，这是一个真正的挑战。

我要说的很对：我有一个引用自身的实体。例如，一个类别可以有一个父类别...为此，我从一个现有表中生成了一个实体...

我尝试使用fetch = fetchtype.eager来获取数据，但未提供预期的结果。

这是我的实体：

package com.company.app.model;

import java.io.Serializable;
import javax.persistence.*;

import com.fasterxml.jackson.annotation.JsonBackReference;
import com.fasterxml.jackson.annotation.JsonManagedReference;

import java.util.Date;
import java.util.List;

@Entity
@Table(name="categories")
@NamedQuery(name="Category.findAll", query="SELECT c FROM Category c")
public class Category implements Serializable {
    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue
    private Long id;

    ....

    //bi-directional many-to-one association to Category
    @ManyToOne
    @JsonManagedReference
    private Category category;

    //bi-directional many-to-one association to Category
    @OneToMany(mappedBy="category", fetch = FetchType.EAGER) 
    @JsonBackReference
    private List<Category> categories;

    //bi-directional many-to-one association to CategoryProduct
    @OneToMany(mappedBy="category")
    @JsonBackReference
    private List<CategoryProduct> categoryProducts;


    public Category() {
    }

    // Getters, setters and other methods generated with JPA

}

我的问题是我想生成一个Json，其中的“顶级”类别没有父母及其所有子类别。从技术上来说看起来像这样

    [  
       { 
          // Top level category 
          "id":1,
          "name":"....",
          "desc": "....."
          "children" : [
                {
                  "id":12,
                  "name":"....",
                  "desc": "....."
                }, 
                {
                  "id":14,
                  "name":"....",
                  "desc": "....."
                }
                ...
            ]
          "admin":{  
             "id":1,
             "createdAt":1541869810000,
             "deletedAt":null,
             "email":"david.vera@9online.fr",
             "login":"admin",
             "name":"Vera",
             "password":"admin",
             "surname":"David",
             "updatedAt":1542150000000
          },
       }
    ]

在我的控制器中，我有一种列出类别的方法，它可以按预期工作。

@GetMapping(path="/categories", produces= {"application/json"})
public List<Category> getAllCategories(Model model) {
    return categoryRepository.findAll();
}

感谢您的帮助

带有Spring MVC Rest API的包含类别和子类别的JSON

0 个答案: