Java tutorial
/* * $Id$ * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 cn.homecredit.web.listener; import java.io.File; import java.io.IOException; import java.net.URL; import java.util.Collections; import java.util.HashMap; import java.util.Map; import java.util.Properties; import java.util.jar.JarFile; import java.util.jar.Manifest; import javax.servlet.ServletContext; import org.apache.commons.lang.StringUtils; import org.apache.felix.framework.Felix; import org.apache.felix.framework.util.FelixConstants; import org.apache.felix.main.AutoProcessor; import org.apache.felix.main.Main; import org.apache.struts2.ServletActionContext; import org.apache.struts2.osgi.host.BaseOsgiHost; import org.apache.struts2.osgi.host.FelixOsgiHost; import org.osgi.framework.Bundle; import org.osgi.framework.BundleContext; import org.osgi.framework.Constants; import com.opensymphony.xwork2.ActionContext; import com.opensymphony.xwork2.FileManager; import com.opensymphony.xwork2.FileManagerFactory; import com.opensymphony.xwork2.config.ConfigurationException; import com.opensymphony.xwork2.util.finder.ResourceFinder; import com.opensymphony.xwork2.util.logging.Logger; import com.opensymphony.xwork2.util.logging.LoggerFactory; /** * Apache felix implementation of an OsgiHost * See http://felix.apache.org/site/apache-felix-framework-launching-and-embedding.html * <br/> * Servlet config params: * <p>struts.osgi.clearBundleCache: Defaults to "true" delete installed bundles when the comntainer starts</p> * <p>struts.osgi.logLevel: Defaults to "1". Felix log level. 1 = error, 2 = warning, 3 = information, and 4 = debug </p> * <p>struts.osgi.runLevel: Defaults to "3". Run level to start the container.</p> */ public class MyOsgiHost extends BaseOsgiHost { private static final Logger LOG = LoggerFactory.getLogger(FelixOsgiHost.class); protected Felix felix; protected void startFelix() { //load properties from felix embedded file Properties configProps = getProperties("default.properties"); // Copy framework properties from the system properties. Main.copySystemProperties(configProps); replaceSystemPackages(configProps); //struts, xwork and felix exported packages Properties strutsConfigProps = getProperties("struts-osgi.properties"); addExportedPackages(strutsConfigProps, configProps); //find bundles and adde em to autostart property addAutoStartBundles(configProps); // Bundle cache String storageDir = System.getProperty("java.io.tmpdir") + ".felix-cache"; configProps.setProperty(Constants.FRAMEWORK_STORAGE, storageDir); if (LOG.isDebugEnabled()) LOG.debug("Storing bundles at [#0]", storageDir); String cleanBundleCache = getServletContextParam("struts.osgi.clearBundleCache", "true"); if ("true".equalsIgnoreCase(cleanBundleCache)) { if (LOG.isDebugEnabled()) LOG.debug("Clearing bundle cache"); configProps.put(FelixConstants.FRAMEWORK_STORAGE_CLEAN, FelixConstants.FRAMEWORK_STORAGE_CLEAN_ONFIRSTINIT); } //other properties configProps.put(FelixConstants.SERVICE_URLHANDLERS_PROP, "true"); configProps.put(FelixConstants.LOG_LEVEL_PROP, getServletContextParam("struts.osgi.logLevel", "1")); configProps.put(FelixConstants.BUNDLE_CLASSPATH, "."); configProps.put(FelixConstants.FRAMEWORK_BEGINNING_STARTLEVEL, getServletContextParam("struts.osgi.runLevel", "3")); try { felix = new Felix(configProps); felix.init(); AutoProcessor.process(configProps, felix.getBundleContext()); felix.start(); if (LOG.isTraceEnabled()) { LOG.trace("Apache Felix is running"); } } catch (Exception ex) { throw new ConfigurationException("Couldn't start Apache Felix", ex); } addSpringOSGiSupport(); //add the bundle context to the ServletContext servletContext.setAttribute(OSGI_BUNDLE_CONTEXT, felix.getBundleContext()); } @Override public void init(ServletContext servletContext) { this.servletContext = servletContext; startFelix(); } @Override public Map<String, Bundle> getBundles() { Map<String, Bundle> bundles = new HashMap<String, Bundle>(); for (Bundle bundle : felix.getBundleContext().getBundles()) { bundles.put(bundle.getSymbolicName(), bundle); } return Collections.unmodifiableMap(bundles); } @Override public Map<String, Bundle> getActiveBundles() { Map<String, Bundle> bundles = new HashMap<String, Bundle>(); for (Bundle bundle : felix.getBundleContext().getBundles()) { if (bundle.getState() == Bundle.ACTIVE) { bundles.put(bundle.getSymbolicName(), bundle); } } return Collections.unmodifiableMap(bundles); } @Override public BundleContext getBundleContext() { return felix.getBundleContext(); } @Override public void destroy() throws Exception { felix.stop(); if (LOG.isTraceEnabled()) { LOG.trace("Apache Felix has stopped"); } } @Override protected void addSpringOSGiSupport() { // see the javadoc for org.springframework.osgi.web.context.support.OsgiBundleXmlWebApplicationContext for more details // OsgiBundleXmlWebApplicationContext expects the the BundleContext to be set in the ServletContext under the attribute // OsgiBundleXmlWebApplicationContext.BUNDLE_CONTEXT_ATTRIBUTE try { Class clazz = Class .forName("org.springframework.osgi.web.context.support.OsgiBundleXmlWebApplicationContext"); String key = (String) clazz.getDeclaredField("BUNDLE_CONTEXT_ATTRIBUTE").get(null); servletContext.setAttribute(key, felix.getBundleContext()); } catch (ClassNotFoundException e) { if (LOG.isDebugEnabled()) { LOG.debug("Spring OSGi support is not enabled"); } } catch (Exception e) { if (LOG.isErrorEnabled()) { LOG.error( "The API of Spring OSGi has changed and the field [#0] is no longer available. The OSGi plugin needs to be updated", e, "org.springframework.osgi.web.context.support.OsgiBundleXmlWebApplicationContext.BUNDLE_CONTEXT_ATTRIBUTE"); } } } protected String getVersion(URL url) { if ("jar".equals(url.getProtocol())) { try { JarFile jarFile = new JarFile(new File(URLUtil.normalizeToFileProtocol(url).toURI())); Manifest manifest = jarFile.getManifest(); if (manifest != null) { String version = manifest.getMainAttributes().getValue("Bundle-Version"); if (StringUtils.isNotBlank(version)) { return getVersionFromString(version); } } else { //try to get the version from the file name return getVersionFromString(jarFile.getName()); } } catch (Exception e) { if (LOG.isErrorEnabled()) { LOG.error("Unable to extract version from [#0], defaulting to '1.0.0'", url.toExternalForm()); } } } return "1.0.0"; } protected Properties getProperties(String fileName) { ResourceFinder finder = new ResourceFinder(""); try { return finder.findProperties(fileName); } catch (IOException e) { if (LOG.isErrorEnabled()) { LOG.error("Unable to read property file [#]", fileName); } return new Properties(); } } }