code: private void initConfigPropertyResolver(ServletContext context) {
  		String configPropertyResolverClass = getInitParameter("configPropertyResolverClass");
  		// Load a custom class to set configPropertyResolver
  		configPropResolver = null;
  		if (null != configPropertyResolverClass) {
  			configPropResolver = (ConfigPropertyResolver) ClassLoaderResourceUtils
  					.buildObjectInstance(configPropertyResolverClass);
  			if (configPropResolver instanceof ServletContextAware) {
  				((ServletContextAware) configPropResolver).setServletContext(context);
  			}
  		}
  	}
docs: Initialize the config property resolver
  
  @param context
  the servlet context