Exception in thread "main" org.hibernate.PropertyValueException: not-null property references a null or transient value : Product.Name

Question

I have a main class where error(at Connect.main(Connect.java:53))

public class Connect {
public static void main(String[] args) throws SQLException {
    SessionFactory factory = new Configuration().configure("hibernate.cfg.xml").
            addAnnotatedClass(Product.class).
            addAnnotatedClass(Customer.class).
            addAnnotatedClass(CustomerHistory.class).
            buildSessionFactory();

    Session session = factory.openSession();
    session.beginTransaction();

    //Drop tablets

    Query Queri = session.createQuery("DELETE CustomerHistory");
    Queri.executeUpdate();

    Queri = session.createQuery("DELETE Customer");
    Queri.executeUpdate();

    Queri = session.createQuery("DELETE Product");
    Queri.executeUpdate();

    //Add customers
    String[] Customers = {"Лис","Пес","Кот"};
    for(int i = 1; i <= Customers.length;i++){
        Customer customer = new Customer();
        customer.setId(i);
        customer.setName(Customers[i-1]);
        session.save(customer);
    }

    //Add products and buy
    HashMap<String, Integer> products = new HashMap<String, Integer>();
    products.put("Картошка", 50);
    products.put("Мюсли", 30);
    products.put("Пепса", 20);

    int b = 1;
    for(String key : products.keySet()){
        Product product = new Product();
        product.setId(b);
        product.setName(key);
        product.setPrice(products.get(key));
        session.save(product);
        

        CustomerHistory history = new CustomerHistory();
        history.setId(b);
        history.setName(Customers[b-1]);
        history.setNameProduct(key);
        session.save(history);
        b++;
    }
    session.getTransaction().commit();

    //Scanner
    Scanner scanner =  new Scanner(System.in);
    int command;
    do{
        System.out.println("Введите цифру для запроса");
        System.out.println("1 - посмотреть какие товары покупал клиент");
        System.out.println("2 - какие клиенты купили определенный товар");
        System.out.println("3 - покупка товара");
        System.out.println("4 - удалить из базы покупателя");
        System.out.println("5 - выход");
        System.out.println("6 - сколько стоил товар в момент покупки клиентом");

        command = Integer.parseInt(scanner.nextLine());
        switch (command){
            case 1:
                session.beginTransaction();
                System.out.println("Введите имя клиента");
                Queri = session.createQuery("from CustomerHistory WHERE Name = :x");
                Queri.setParameter("x",scanner.nextLine());
                List<CustomerHistory> cus = Queri.list();
                for(CustomerHistory s : cus)
                { System.out.println("id="+s.getId() + " Name="+s.getName()+" NameProduct="+s.getNameProduct());}
                session.getTransaction().commit();
                break;
            case 2:
                session.beginTransaction();
                System.out.println("Введите имя товара");
                Queri = session.createQuery("from CustomerHistory WHERE NameProduct = :x");
                Queri.setParameter( "x", scanner.nextLine());
                cus = Queri.list();
                for(CustomerHistory s : cus)
                { System.out.println("id="+s.getId() + " Name="+s.getName()+" NameProduct="+s.getNameProduct());}
                session.getTransaction().commit();
                break;
            case 3:
                session.beginTransaction();
                System.out.println("Введите имя человека и товар, который он покупает");
                Queri = session.createNativeQuery("INSERT INTO CustomerHistory (id, Name, NameProduct) VALUES (:x,:y,:z)");
                Queri.setParameter( "x", b+1) ;
                Queri.setParameter( "y", scanner.nextLine()) ;
                Queri.setParameter( "z", scanner.nextLine()) ;
                Queri.executeUpdate();
                session.getTransaction().commit();
                break;
            case 4:
                session.beginTransaction();
                System.out.println("Введите имя клиента для удаления");
                Queri = session.createQuery("DELETE Customer WHERE Name = :x");
                Queri.setParameter( "x", scanner.nextLine());
                Queri.executeUpdate();
                session.getTransaction().commit();
                break;
            case 6:
                session.beginTransaction();
                Queri = session.createQuery("select g1.id,g1.Name,g1.NameProduct,g2.Price from CustomerHistory as g1 inner join Product as g2 on g1.id = g2.id");
                List<Object[]> sus = (List<Object[]>) Queri.list();
                for(Object[] x : sus)
                { System.out.println("id="+x[0]+ " Покупатель=" + x[1] + " Продукт=" +x[2] + " Цена=" +x[3]);}
                session.getTransaction().commit();
                break;
            default:
                System.out.println("Завершение программы");
        }

    }
    while (command != 5);
}
}

Class Customer

@Entity
public class Customer {
@Id
@Column (name = "id", nullable = false)
private int id;

public int getId(){return id;}

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

@Column (name = "Name", nullable = false)
private String Name;

public String getName(){return Name;}

public void setName(String name){ Name = name;}
}

Class Product where does the error possibly come from

@Entity
public class Product {
@Id
@Column(name = "id",nullable = false)
private int id;

public int getId(){return id;}

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

@Column(name = "Name", nullable = false)
private String Name;

public String getName(){return Name;}

public void setName(String Name){Name = Name;}

@Column(name = "Price",nullable = false)
private int Price;

public int getPrice(){return Price;}

public void setPrice(int price){this.Price = price;}
}

And last class CustomerHistory its all buy history

@Entity
public class CustomerHistory {
@Id
@Column(name = "id", nullable = false)
private Integer id;

@Column(name = "Name", nullable = false)
private String Name;

public String getName(){return Name;}

public void setName(String name){this.Name = name;}

@Column(name = "NameProduct",nullable = false)
private String NameProduct;

Integer getId(){return id;}

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

public String getNameProduct(){return NameProduct;}

public void setNameProduct(String NameProduct){this.NameProduct = NameProduct;}
}