Writing Custom PropertyAccessor for struts 2 OGNL

[avaya sahu]

Hi,
I am trying to register my custom PropertyAccessor. I am able to register it and is working fine when expression is directly evaluated against it using Ognl. but the same is not working from value stack. Asper my understanding the property is searched in the stack till it find a match or reach end of the stack. Am I right? please help. below is the code

package com;

import ognl.Ognl;
import ognl.OgnlRuntime;

import com.opensymphony.xwork2.util.OgnlValueStack;
public class OGNLTest {
public static void main(String[] args) throws Exception{
	OgnlRuntime.setPropertyAccessor(CustomBean.class, new MyPropertyAccessor());
	OgnlValueStack stack = new OgnlValueStack();
	CustomBean bean = new CustomBean();
	stack.push(bean);
	System.out.println(stack.findValue("room")); //output null, why?
	System.out.println(Ognl.getValue("room", bean)); // output $Aroom
}
}
//=======================================================

package com;

import java.util.Map;

import ognl.OgnlException;
import ognl.PropertyAccessor;

public class MyPropertyAccessor implements PropertyAccessor {
	public MyPropertyAccessor() {
		System.out.println("Working.........");
	}
	public Object getProperty(Map context, Object target, Object name)
			throws OgnlException {
		CustomBean cb = (CustomBean) target;
		String value = cb.getValue((String)name);
		return value;
	}
	public void setProperty(Map context, Object target, Object name, Object value) 
			throws OgnlException {
		System.out.println("Do this......");
	}
}
//===========================================================

package com;

public class CustomBean {
	public CustomBean() {
		
	}
	public String getValue(String propertyName){
		if (propertyName.endsWith("room")) {
			return "$A"+propertyName;
		}
		return null;
	}
	public void setValue(String propertyName, String name){
	}
}