Java Programming

Have a parent class. Have a child class which extends the parent abstract class. And i invoke the child class using reflection. When i convert the child class to parent class i get ClassCastException. Any ideas? Am i doing something wrong?

public abstract class A {
    public void method1(.. args);
    public void method2(.. args);
}


public class B extends A{
    private static B b = null;
    private B(){
    }
    public static B getInstance(){
        if(b == null){
            b = new B();
        }
        return b;
    }

    public void method1(.. args){
    //implementation
    }
    public void method2(.. args){
    //implementation
    }
}

public class C{
    private Map classmap = new HashMap();
    public void loadmethods(){
        Class thisClass;
        try{
            thisClass = Class.forName("B");
            Method instanceMethod = thisClass.getDeclaredMethod("getInstance", (Class[])null);
            Object instance = instanceMethod.invoke(null, (Object[])null);
            classmap.put("B", instance);
        } catch(Exception ex){
        //log the error
        }
    }
    public A getInstance(String classname){
        return classmap .get(classname);
    }
   
    public static void main(String[] args){
        C c = new C();
        c.loadmethods();
        A a = null;
        try{
            a = c.getInstance("B");//ClassCastException happening here
        } catch(Exception ex){
            //Can catch the exception here.
        }
    }
}