spring-boot - Spring ブート JPA で org.springframework.data.util.Pair を使用できない

Question

スプリング ブート 2.2.5

1つのカートには多くの商品があります。製品と製品の数量を保管する必要があります。だから私はこれに地図を使います。だからここに私のモデル：

import javax.persistence.*;
import java.util.*;
import org.springframework.data.util.Pair;

@Entity
public class Cart {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
       @OneToMany(mappedBy = "cart", fetch = FetchType.EAGER,
            cascade = CascadeType.ALL)
    private Map<Product, Integer> products;

}

@Entity
public class Product {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    @ManyToOne(fetch = FetchType.EAGER, optional = false)
    @JoinColumn(name = "cart_id", nullable = false)
    private Cart cart;

}

public interface CartRepository extends CrudRepository<Cart, Integer> {

}

しかし、アプリを起動しようとするとエラーが発生します:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'mvcConversionService' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.format.support.FormattingConversionService]: Factory method 'mvcConversionService' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'ordersRepository' defined in com.myproject.repo.OrdersRepository defined in @EnableJpaRepositories declared on JpaRepositoriesRegistrar.EnableJpaRepositoriesConfiguration: Cannot resolve reference to bean 'jpaMappingContext' while setting bean property 'mappingContext'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jpaMappingContext': Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: com.myproject.api.model.Cart.products[org.springframework.data.util.Pair]