Change the object instance type : Type Casting « Type Casting « SCJP

import java.util.Vector;

class MyClass {
}

public class MainClass {
  public static void main(String[] argv) {
    Vector v = new Vector();
    v.add(new MyClass());

    MyClass a = (MyClass) v.elementAt(0);
  }
}

4.1.Type Casting
	4.1.1.	You can explicitly change the type of a value by casting.
	4.1.2.	Change the object instance type
	4.1.3.	A widening conversion is a conversion from a smaller numeric type to a larger numeric type.
	4.1.4.	A narrowing conversion is a conversion from a larger numeric type to a smaller numeric type.