wro4j-core/src/main/java/ro/isdc/wro/http/WroFilter.java
private void registerChangeListeners() {
    wroConfiguration.registerCacheUpdatePeriodChangeListener(new PropertyChangeListener() {
      public void propertyChange(final PropertyChangeEvent event) {
        // reset cache headers when any property is changed in order to avoid browser caching
        headersConfigurer = newResponseHeadersConfigurer();
        wroManagerFactory.onCachePeriodChanged(valueAsLong(event.getNewValue()));
      }
    });
    wroConfiguration.registerModelUpdatePeriodChangeListener(new PropertyChangeListener() {
      public void propertyChange(final PropertyChangeEvent event) {
        headersConfigurer = newResponseHeadersConfigurer();
        wroManagerFactory.onModelPeriodChanged(valueAsLong(event.getNewValue()));
      }
    });
    LOG.debug("Cache & Model change listeners were registered");
  }
private void registerChangeListeners() {
    wroConfiguration.registerCacheUpdatePeriodChangeListener(new PropertyChangeListener() {
      public void propertyChange(final PropertyChangeEvent event) {
        // reset cache headers when any property is changed in order to avoid browser caching
        headersConfigurer = newResponseHeadersConfigurer();
        wroManagerFactory.onCachePeriodChanged(valueAsLong(event.getNewValue()));
      }
    });
    wroConfiguration.registerModelUpdatePeriodChangeListener(new PropertyChangeListener() {
      public void propertyChange(final PropertyChangeEvent event) {
        headersConfigurer = newResponseHeadersConfigurer();
        wroManagerFactory.onModelPeriodChanged(valueAsLong(event.getNewValue()));
      }
    });
    LOG.debug("Cache & Model change listeners were registered");
  }
Register property change listeners.