Java tutorial
/* * $Id$ * -------------------------------------------------------------------------------------- * Copyright (c) MuleSoft, Inc. All rights reserved. http://www.mulesoft.com * * The software in this package is published under the terms of the CPAL v1.0 * license, a copy of which has been included with this distribution in the * LICENSE.txt file. */ package org.mule.module.management.agent; import org.mule.AbstractAgent; import org.mule.api.MuleException; import org.mule.api.lifecycle.InitialisationException; import org.mule.config.i18n.CoreMessages; import org.mule.module.management.i18n.ManagementMessages; import org.mule.module.management.support.AutoDiscoveryJmxSupportFactory; import org.mule.module.management.support.JmxSupport; import org.mule.module.management.support.JmxSupportFactory; import java.util.List; import java.util.concurrent.atomic.AtomicReference; import javax.management.InstanceNotFoundException; import javax.management.MBeanRegistrationException; import javax.management.MBeanServer; import javax.management.MBeanServerFactory; import javax.management.MalformedObjectNameException; import javax.management.ObjectName; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.tanukisoftware.wrapper.WrapperSystemPropertyUtil; import org.tanukisoftware.wrapper.jmx.WrapperManager; import org.tanukisoftware.wrapper.jmx.WrapperManagerMBean; import org.tanukisoftware.wrapper.security.WrapperPermission; /** * This agent integrates Java Service Wrapper into Mule. See * <a href="http://wrapper.tanukisoftware.org">http://wrapper.tanukisoftware.org</a> * for more details. */ public class WrapperManagerAgent extends AbstractAgent { /** * MBean name to register under. */ public static final String WRAPPER_JMX_NAME = "name=WrapperManager"; /** * For cases when Mule is embedded in another process and that external process * had registered the MBean. */ public static final String DEFAULT_WRAPPER_MBEAN_NAME = "org.tanukisoftware.wrapper:type=WrapperManager"; private static final Log logger = LogFactory.getLog(WrapperManagerAgent.class); /** * This property is set by the native launcher, used for extra checks. */ private static final String WRAPPER_SYSTEM_PROPERTY_NAME = "wrapper.native_library"; private MBeanServer mBeanServer; private ObjectName wrapperName; private JmxSupportFactory jmxSupportFactory = AutoDiscoveryJmxSupportFactory.getInstance(); private JmxSupport jmxSupport = jmxSupportFactory.getJmxSupport(); // atomic reference to avoid unnecessary construction calls private final AtomicReference<WrapperManagerMBean> wrapperManagerRef = new AtomicReference<WrapperManagerMBean>(); public WrapperManagerAgent() { super("wrapper-manager"); } @Override public void initialise() throws InitialisationException { try { List<?> servers = MBeanServerFactory.findMBeanServer(null); if (servers.isEmpty()) { throw new InitialisationException(ManagementMessages.noMBeanServerAvailable(), this); } mBeanServer = (MBeanServer) servers.get(0); /* Perform an extra check ourselves. If 'wrapper.native_library' property has not been set, which is the case for embedded scenarios, don't even try to construct the wrapper manager bean, as it performs a number of checks internally and outputs a very verbose warning. */ boolean launchedByWrapper; if (System.getProperty(WRAPPER_SYSTEM_PROPERTY_NAME) == null) { launchedByWrapper = false; } // Check if an external process registered a wrapper MBean under default name. else if (mBeanServer.isRegistered(jmxSupport.getObjectName(DEFAULT_WRAPPER_MBEAN_NAME))) { logger.info("Mule is embedded in a container already launched by a wrapper." + "Duplicates will not be registered. Use the " + DEFAULT_WRAPPER_MBEAN_NAME + " MBean " + "instead for control."); unregisterMeQuietly(); return; } else { lazyInitWrapperManager(); launchedByWrapper = wrapperManagerRef.get().isControlledByNativeWrapper(); } if (!launchedByWrapper) { logger.info("This JVM hasn't been launched by the wrapper, the agent will not run."); unregisterMeQuietly(); return; } final boolean containerMode = muleContext.getConfiguration().isContainerMode(); if (containerMode) { // container mode, register mbean under Mule domain, no duplicates under each app's domain wrapperName = jmxSupport .getObjectName(JmxSupport.DEFAULT_JMX_DOMAIN_PREFIX + ":" + WRAPPER_JMX_NAME); if (mBeanServer.isRegistered(wrapperName)) { // ignore duplicate invocations when running in Mule container mode return; } } else { // embedded case, use Mule's single domain wrapperName = jmxSupport .getObjectName(jmxSupport.getDomainName(muleContext) + ":" + WRAPPER_JMX_NAME); } unregisterMBeansIfNecessary(); mBeanServer.registerMBean(wrapperManagerRef.get(), wrapperName); } catch (InitialisationException iex) { // rethrow throw iex; } catch (Exception e) { throw new InitialisationException(CoreMessages.failedToStart("wrapper agent"), e, this); } } @Override public void start() throws MuleException { // nothing to do } @Override public void stop() throws MuleException { // nothing to do } @Override public void dispose() { try { unregisterMBeansIfNecessary(); } catch (Exception e) { logger.error( "Couldn't unregister MBean: " + (wrapperName != null ? wrapperName.getCanonicalName() : "null"), e); } } // ///////////////////////////////////////////////////////////////////////// // Getters and setters // ///////////////////////////////////////////////////////////////////////// @Override public String getDescription() { WrapperManagerMBean wm = wrapperManagerRef.get(); if (wm == null) { return "Wrapper Manager"; } else { return "Wrapper Manager: Mule PID #" + getJavaPID() + ", Wrapper PID #" + getWrapperPID(); } } /** * This method is a copy of the implementation of * {@link WrapperManagerMBean#getJavaPID()} and it is here because that method is * not present in the {@link WrapperManagerMBean} until version 3.2.3. * SpringSource's TC Server uses The wrapper version 3.2.0 so having this method * here allows us to be compatible with TC Server. * * @return The PID of the Java process. * @see <a href="http://www.mulesoft.org/jira/browse/MULE-5106">MULE-5106</a> */ public static int getJavaPID() { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new WrapperPermission("getJavaPID")); } return WrapperSystemPropertyUtil.getIntProperty("wrapper.java.pid", 0); } /** * This method is a copy of the implementation of * {@link WrapperManagerMBean#getWrapperPID()} and it is here because that method * is not present in the {@link WrapperManagerMBean} until version 3.2.3. * SpringSource's TC Server uses The wrapper version 3.2.0 so having this method * here allows us to be compatible with TC Server. * * @return The PID of the Wrapper process. * @see <a href="http://www.mulesoft.org/jira/browse/MULE-5106">MULE-5106</a> */ public static int getWrapperPID() { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new WrapperPermission("getWrapperPID")); } return WrapperSystemPropertyUtil.getIntProperty("wrapper.pid", 0); } protected void lazyInitWrapperManager() { WrapperManagerMBean wm = wrapperManagerRef.get(); if (wm != null) { return; } wm = new WrapperManager(); wrapperManagerRef.compareAndSet(null, wm); } /** * Unregister all MBeans if there are any left over the old deployment */ protected void unregisterMBeansIfNecessary() throws MalformedObjectNameException, InstanceNotFoundException, MBeanRegistrationException { if (mBeanServer == null || wrapperName == null) { return; } if (mBeanServer.isRegistered(wrapperName)) { mBeanServer.unregisterMBean(wrapperName); } } }