AutoClearCaches.java

package zk.example.devconfig;

import org.zkoss.bind.BindComposer;
import org.zkoss.bind.impl.BinderImpl;
import org.zkoss.zel.BeanELResolver;
import org.zkoss.zel.impl.util.ConcurrentCache;
import org.zkoss.zk.ui.Desktop;
import org.zkoss.zk.ui.Execution;
import org.zkoss.zk.ui.util.DesktopInit;
import org.zkoss.zk.ui.util.ExecutionInit;

import java.lang.reflect.Field;
import java.util.Map;

public class AutoClearCaches implements DesktopInit, ExecutionInit {

	/**
	 * pick this if you want to clear the caches only once per page refresh (F5)
	 */
	@Override
	public void init(Desktop desktop, Object o) throws Exception {
//		clearBeanElResolverCache();
//		clearMvvmCaches();
	}

	/**
	 * pick this if you want to clear the caches with every Execution
	 * this allows code changes to MVVM annotated methods and bean properties without having to reload a page
	 */
	@Override
	public void init(Execution execution, Execution parent) throws Exception {
		if(parent == null) {
			clearBeanElResolverCache();
			clearMvvmCaches();
		}
	}

	public static void clearMvvmCaches() throws Exception {
		clearMap(BinderImpl.class, "_initMethodCache");
		clearMap(BinderImpl.class, "_destroyMethodCache");
		clearMap(BinderImpl.class, "_commandMethodCache");
		clearMap(BinderImpl.class, "_globalCommandMethodCache");
		clearMap(BindComposer.class, "_afterComposeMethodCache");
		clearMap(BindComposer.class, "_historyPopStateMethodCache");
	}

	public static void clearBeanElResolverCache() throws Exception {
		ConcurrentCache cache = getField(BeanELResolver.class, "cache");
		clearMap(cache, "longterm");
		clearMap(cache, "eden");
	}

	private static void clearMap(Object obj, String fieldName) throws Exception {
		Map map = getField(obj, fieldName);
		System.out.println(String.format("Clearing map '%s' on %s (%s)", fieldName, obj, map));
		map.clear();
	}

	private static <T> T getField(Object obj, String fieldName) throws Exception {
		Class cls = obj instanceof Class ? (Class) obj : obj.getClass();
		Field field = cls.getDeclaredField(fieldName);
		field.setAccessible(true);
		return (T) field.get(obj);
	}
}

zk.xml

<zk>   
  <!-- enable listener -->
	<listener>
		<listener-class>zk.example.devconfig.AutoClearCaches</listener-class>
	</listener>
</zk>