about inner join and inner join fetch again

[peter tong]

public class Main {

public static void main(String[] args) {
HibernateUtil.setup("create table Supplier ( id int, name VARCHAR);");
HibernateUtil.setup("create table Product ( id int, name VARCHAR, description VARCHAR, price double,supplierId int);");

prepareData();
Session session = HibernateUtil.currentSession();

        String hql = "from Supplier s inner join fetch s.products as p";
        Query query = session.createQuery(hql);
        List results = query.list();
        displaySupplierList(results);
        
        // without fetch, exception!!
        String hql2 = "from Supplier s inner join s.products as p";
        Query query2 = session.createQuery(hql2);
        List results2 = query2.list();
        displaySupplierList(results2);        
}
    static public void displaySupplierList(List list) {
        Iterator iter = list.iterator();
        if (!iter.hasNext()) {
            System.out.println("No suppliers to display.");
            return;
        }        
        while (iter.hasNext()) {
            Supplier supplier = (Supplier) iter.next();
            String msg = supplier.getName();
            String msg2 = ((Product)supplier.getProducts().get(0)).getName();
            System.out.println(msg + " " + msg2);
        }
    }
 
 
 

private static void prepareData(){
        Session session = HibernateUtil.currentSession();
 
        Supplier supplier1 = new Supplier();
        supplier1.setName("Supplier Name 1");
        session.save(supplier1);
        
        Supplier supplier2 = new Supplier();
        supplier2.setName("Supplier Name 2");
        session.save(supplier2);        
        
        Product product1 = new Product("Product 1","Name for Product 1", 2.0);
        product1.setSupplier(supplier1);
        supplier1.getProducts().add(product1);
        session.save(product1);
        
        Product product12 = new Product("Product 2","Name for Product 2", 22.0);
        product12.setSupplier(supplier1);
        supplier1.getProducts().add(product12);        
        session.save(product12);
        
        Product product2 = new Product("Product 3", "Name for Product 3", 30.0);
        product2.setSupplier(supplier2);
        supplier2.getProducts().add(product2);
        session.save(product2);
        
        session.flush();
        HibernateUtil.closeSession();
}
}

the result in console is
...
[java] Hibernate: select supplier0_.id as id0_, products1_.id as id1_, supplier0_.name as name1_0_, products1_.name as name0_1_, products1_.description as descript3_0_1_, products1_.price as price0_1_, products1_.supplierId as supplierId0_1_, products1_.supplierId as supplierId__, products1_.id as id__ from Supplier supplier0_ inner join Product products1_ on supplier0_.id=products1_.supplierId
[java] Supplier Name 1 Product 1
[java] Supplier Name 1 Product 1
[java] Supplier Name 2 Product 3
[java] Hibernate: select supplier0_.id as id0_, products1_.id as id1_, supplier0_.name as name1_0_, products1_.name as name0_1_, products1_.description as descript3_0_1_, products1_.price as price0_1_, products1_.supplierId as supplierId0_1_ from Supplier supplier0_ inner join Product products1_ on supplier0_.id=products1_.supplierId
[java] Exception in thread "main" java.lang.ClassCastException: [Ljava.lang.Object; cannot be cast to Supplier [java] at Main.displaySupplierList(Main.java:38)
[java] at Main.main(Main.java:24)
[java] Java Result: 1

if not using fetch, iter.next() cannot be cast to Supplier, why?