Sorry for the crappy title I failed to think of a better version for my Java question. I am right now using Java version: 1.6.0_18 and Netbeans version: 6.8

Now for the question.

What I've done is created a class with only one protected int property and next I made a public method to Set the int property to a given value. Then I made an object of that class and used said public method to set the int property to 5. Now I need your help to create another class that will take said object and expose it's protected int property.

The way I could think of doing this was to create a sub class to inherit said class and then create a method to Get the int property of the super class. I kind of succeeded to create the code to Get the int property but now I can't figure out how to use this new sub class to reference the object of the super class.

Here are the 2 classes I have thus far:

public class A
{
  protected int iNumber;

  public void setNumber ( int aNumber )
  {
    iNumber = aNumber;
  }
}

public class B extends A
{
  public int getNumber()
  {
   return super.iNumber;
  }
}

I created an object of 'A' and used its method to set its property to 5, like this:

A objA = new A();
objA.setNumber ( 5 );

Now I want to create an object of 'B' to output the int stored within the property of 'objA'. I've tried to run this code:

B objB = (B) objA;
String aNumber_String = String.valueOf( objB.getNumber() );
System.out.println( aNumber_String );

but I got the error: "java.lang.ClassCastException" on the first line

 B objB = (B) objA; 

Please is there anyway of doing what I am trying to do?

P.S. I am hoping to make this idea work because I do not want to edit class A (unless I have no choice) by giving it a getter method.

P.P.S Also I know it's a 'bad' idea to expose the property instead of making it private and use public setter / getter methods but I like it this way :).

Edit: Added code tags