java中类的提升所导致的问题

import java.util.*;
class Person
{
    private String name;
    private int age;
    Person(String name,int age)
    {
        this.name = name;
        this.age = age;
    }
    public String getName()
    {
        return name;
    }
    public int getAge()
    {
        return age;
    }
}
class Demo
{
        public static void main(String[] args)
        {
            ArrayList al = new ArrayList();
            al.add(new Person("lisi01",30));
            al.add(new Person("lisi02",32));
            al.add(new Person("lisi03",33));
            al.add(new Person("lisi04",35));
            Iterator it = al.iterator();
            while(it.hasNext())
            {
                System.out.println(it.next().getName());
            }
        }

}

使用it.next().getName()会导致问题，

原因是将  “lisi01”,30  存入ArrayList中时会将其提升为Object，it.next()返回的是Object类型的对象，Object中没有getName方法，

应强制转换：

while(it.hasNext())
{
    Person p = (Person)it.next();
    System.out.println(it.next().getName());
}