How to programmatically resolve property placeholder in Spring

I currently work on a web application based on Spring 3.1.0.M1, annotations based, and I have a problem with resolving property placeholders in one specific place of my application.

Here is the story.

1) In my web application context (loaded by DispatcherServlet), i have

mvc-config.xml:

<!-- Handles HTTP GET requests for /resources/version/**  -->
<resources mapping="/${app.resources.path}/**" location="/static/" cache-period="31556926"/> 

...

<!-- Web properties -->
<context:property-placeholder location="
    classpath:app.properties
    "/>

2) Inside app.properties, there are 2 properties, among others:

app.properties:

# Properties provided (filtered) by Maven itself
app.version: 0.1-SNAPSHOT
...

# Static resources mapping
app.resources.path: resources/${app.version}

3) I have a JSP custom tag in my JSP 2.1 templates. This tag is responsible for full resource path construction depending on environment settings, app version, spring theme selection etc. Custom tag class extends spring:url implementation class, so it may be considered a usual url tag but with some additional knowledge about proper path.

My problem is that I cannot get ${app.resources.path} correctly resolved in my JSP custom tag implementation. JSP custom tags are managed by servlet container, not Spring, and therefore dont participate in DI. So I cannot just use usual @Value("${app.resources.path}") and get it resolved by Spring automatically.

All I have there is the web application context instance, so I have to resolve my property programmatically.

So far I tried:

ResourceTag.java:

// returns null
PropertyResolver resolver = getRequestContext().getWebApplicationContext().getBean(PropertyResolver.class);
resolver.getProperty("app.resources.path");


// returns null, its the same web context instance (as expected)
Property