JPA Mapper

One to Many

Class Category

@Entity(name = "Category")
public class Category {
    private short id;  
    private String name;
    @OneToMany(mappedBy = "category")
    private List<Product> products;
}

Class Product

@Entity(name = "Product")
public class Product {
    @Id
    private long id;
    private String title;
    @ManyToOne
    @JoinColumn(name = "CategoryId")
    private Category category;
}

JPA where and pagination

public interface ProductRepository extends PagingAndSortingRepository<Product, Long>, CrudRepository<Product, Long>{
    List<Product> findAllBySubCategoryId(short subCategoryId, Pageable pageable);
    List<Product> findAllBySubCategoryAndIdNot(SubCategory subCategory, long id, Pageable pageable);
    @Query(nativeQuery = true, value = "SELECT p.* FROM Product AS p JOIN SubCategory AS s ON p.SubCategoryId = s.SubCategoryId  AND s.CategoryId = :id")
    List<Product> findAllByCategory(short id, Pageable pageable);
}