simple object type casting

package funds;
class One
{
    void show1()
    {
        System.out.println("one class method");
    }
}
class Two extends One
{
    void show2()
    {
        System.out.println("two class method");
    }
}
public class TypeCastEx3 {
    public static void main(String are[])
    {
        // super class reference to refer to super class object
        One o;
        o=new One();
        o.show1();
        
        //Sub class reference to refer to sub class object
        Two t;
        t=new Two();
        t.show2();
        t.show1();
        
        // super class reference to refer to sub class object
        One o1;
        o1=(One)new Two();
        o1.show1();
        
        //sub class reference to refer to super class object
        Two t1;
        t1=(Two)new One(); //class cast exception
        
        
        // narrowing using sub class object
        One o3;
        o3=(One)new Two();
        Two t2=(Two)o3; //If typecast with 'o' get exception
        t.show1();
        t.show2();
    }
    
}

output:
one class method
two class method
one class method
one class method
one class method
two class method