Java tutorial
/* * (C) Copyright 2011 Nuxeo SA (http://nuxeo.com/) and others. * * 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. * * Contributors: */ package org.nuxeo.ecm.webapp.seam; import java.lang.management.ManagementFactory; import java.util.HashSet; import java.util.Iterator; import java.util.Set; import javax.management.JMX; import javax.management.MBeanServer; import javax.management.MXBean; import javax.management.MalformedObjectNameException; import javax.management.ObjectInstance; import javax.management.ObjectName; import javax.servlet.ServletContextEvent; import javax.servlet.ServletContextListener; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * Listener for Seam cache flush requests * * @since 5.5 */ public class NuxeoSeamWebGate implements ServletContextListener { protected static NuxeoSeamWebGate instance; protected static Log log = LogFactory.getLog(NuxeoSeamWebGate.class); protected boolean initialized; public NuxeoSeamWebGate() { instance = this; } @Override public void contextDestroyed(ServletContextEvent arg0) { initialized = false; } @Override public void contextInitialized(ServletContextEvent arg0) { initialized = true; } @MXBean public interface WebConnector { String getStateName(); } protected final Set<WebConnector> waitingConnectors = fetchConnectors(); protected Set<WebConnector> fetchConnectors() { Set<WebConnector> connectors = new HashSet<WebConnector>(); MBeanServer mbs = ManagementFactory.getPlatformMBeanServer(); ObjectName names; try { names = new ObjectName("Catalina:type=Connector,port=*,address=*"); } catch (MalformedObjectNameException e) { log.error("Cannot query for tomcat connectors", e); return connectors; } Set<ObjectInstance> ois = mbs.queryMBeans(names, null); for (ObjectInstance oi : ois) { WebConnector connector = JMX.newMBeanProxy(mbs, oi.getObjectName(), WebConnector.class); connectors.add(connector); } return connectors; } protected synchronized boolean checkConnectorsUp() { Iterator<WebConnector> it = waitingConnectors.iterator(); while (it.hasNext()) { WebConnector connector = it.next(); if ("STARTED".equals(connector.getStateName())) { it.remove(); } } return waitingConnectors.isEmpty(); } public static boolean isInitialized() { if (instance == null) { return false; } if (instance.initialized == false) { return false; } return instance.checkConnectorsUp(); } }