I created in Spring a JPA repository works nice in the CommandLineRunner but when I use in a @Entity the result is null

Question

I am creating a private ItemsRepository itemsRepository but returns null . I am using @Transient and @Autowired . How I can use a JPA repository inside this class?

package com.example.hibernateonetomany.model;

import com.example.hibernateonetomany.repositories.ItemsRepository;
import org.springframework.beans.factory.annotation.Autowired;

import java.util.Set;

import javax.persistence.*;

@Entity
@Table(name = "CART")
public class Cart {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "cart_id")
    private long id;

   @Transient
   @Autowired
   private ItemsRepository itemsRepository;

   @OneToMany(mappedBy = "cart")
   private Set<Item> items;


    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }


    public Set<Item> getItems() {
        Set<Item> list_temp=itemsRepository.findByCart_Id(id);
        return list_temp;
    }

    public void setItems(Set<Item> items) {
        this.items = items;
    }

} ```