Java tutorial
/* * Copyright 2011 SpringSource * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package grails.validation; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.codehaus.groovy.grails.lifecycle.ShutdownOperations; import java.util.ArrayList; import java.util.List; /** * Binding operations that are deferred until either validate() or save() are called. * * @author Graeme Rocher * @since 2.0 */ public class DeferredBindingActions { private static ThreadLocal<List<Runnable>> deferredBindingActions = new ThreadLocal<List<Runnable>>(); private static Log LOG = LogFactory.getLog(DeferredBindingActions.class); static { ShutdownOperations.addOperation(new Runnable() { public void run() { deferredBindingActions.remove(); } }); } public static void addBindingAction(Runnable runnable) { List<Runnable> bindingActions = getDeferredBindingActions(); bindingActions.add(runnable); } private static List<Runnable> getDeferredBindingActions() { List<Runnable> runnables = deferredBindingActions.get(); if (runnables == null) { runnables = new ArrayList<Runnable>(); deferredBindingActions.set(runnables); } return runnables; } public static void runActions() { List<Runnable> runnables = deferredBindingActions.get(); if (runnables != null) { try { for (Runnable runnable : getDeferredBindingActions()) { if (runnable != null) { try { runnable.run(); } catch (Exception e) { LOG.error("Error running deferred data binding: " + e.getMessage(), e); } } } } finally { clear(); } } } public static void clear() { deferredBindingActions.remove(); } }