Java tutorial
/* * Copyright (c) 2002-2014, Mairie de Paris * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright notice * and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright notice * and the following disclaimer in the documentation and/or other materials * provided with the distribution. * * 3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * * License 1.0 */ package fr.paris.lutece.portal.service.spring; import fr.paris.lutece.portal.service.init.LuteceInitException; import fr.paris.lutece.portal.service.plugin.Plugin; import fr.paris.lutece.portal.service.plugin.PluginEvent; import fr.paris.lutece.portal.service.plugin.PluginEventListener; import fr.paris.lutece.portal.service.plugin.PluginService; import fr.paris.lutece.portal.service.util.AppLogService; import fr.paris.lutece.portal.service.util.AppPathService; import org.apache.commons.lang.StringUtils; import org.springframework.beans.factory.xml.XmlBeanDefinitionReader; import org.springframework.context.ApplicationContext; import org.springframework.context.support.AbstractApplicationContext; import org.springframework.web.context.support.GenericWebApplicationContext; import java.io.File; import java.io.FilenameFilter; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Map; import javax.servlet.ServletContext; /** * This class provides a way to use Spring Framework ligthweight containers * offering IoC (Inversion of Control) features. * @see <a href="http://www.springframework.org">http://www.springframework.org</a> */ public final class SpringContextService implements PluginEventListener { private static final String PATH_CONF = "/WEB-INF/conf/"; private static final String DIR_PLUGINS = "plugins/"; private static final String DIR_OVERRIDE = "override/"; private static final String DIR_OVERRIDE_PLUGINS = DIR_OVERRIDE + DIR_PLUGINS; private static final String SUFFIX_CONTEXT_FILE = "_context.xml"; private static final String FILE_CORE_CONTEXT = "core_context.xml"; private static ApplicationContext _context; private static Map<Class, List> _mapBeansOfType = new HashMap<Class, List>(); private static SpringContextService _instance = new SpringContextService(); /** Creates a new instance of SpringContextService */ private SpringContextService() { } /** * Return an instance, which may be shared or independent, of the given bean name. * This method allows a Spring BeanFactory to be used as a replacement for * the Singleton or Prototype design pattern.<br /> * The bean is retreived from the main context defined in the WEB-INF/conf/core_context.xml. * * @param <T> the generic type * @param strName The bean's name * @return The instance of the bean */ public static <T> T getBean(String strName) { return (T) _context.getBean(strName); } /** * Return an instance of the given bean name loaded by the a Spring BeanFactory. * The bean is retreived from a plugin context defined in the WEB-INF/conf/plugins/[plugin_name]_context.xml. * @param strPluginName The Plugin's name * @param strName The bean's name * @return The instance of the bean * @deprecated use {@link #getBean(String)} instead */ @Deprecated public static Object getPluginBean(String strPluginName, String strName) { return _context.getBean(strName); } /** * Initialize a global Application Context containing all beans (core + plugins) * Now uses GenericApplicationContext for better performances. A wrong formatted file * will not block block context to be built (without the file), but a wrong bean (i.e. cannot * be instantiated) will cause a full context failure. Context is less "failure-friendly" * @param servletContext The servlet context * @throws LuteceInitException The lutece init exception * @since 2.4 */ public static void init(ServletContext servletContext) throws LuteceInitException { try { // Register this service as a PluginEventListener PluginService.registerPluginEventListener(_instance); // timing Date dateBegin = new Date(); // Load the core context file : core_context.xml String strConfPath = AppPathService.getAbsolutePathFromRelativePath(PATH_CONF); String strContextFile = "file:" + strConfPath + FILE_CORE_CONTEXT; GenericWebApplicationContext gwac = new GenericWebApplicationContext(servletContext); gwac.setId(getContextName(servletContext)); XmlBeanDefinitionReader xmlReader = new XmlBeanDefinitionReader(gwac); xmlReader.loadBeanDefinitions(strContextFile); // _context = new ClassPathXmlApplicationContext( strContextFile ); AppLogService.info("Context file loaded : " + FILE_CORE_CONTEXT); // Load all context files found in the conf/plugins directory // Files are loaded separatly with an individual try/catch block // to avoid stopping the process in case of a failure // The global context generation will fail if a bean in any file cannot be built. String strConfPluginsPath = strConfPath + DIR_PLUGINS; File dirConfPlugins = new File(strConfPluginsPath); FilenameFilter filterContext = new ContextFileFilter(); String[] filesContext = dirConfPlugins.list(filterContext); loadContexts(filesContext, strConfPluginsPath, xmlReader); // we now load overriding beans AppLogService.info("Loading plugins context overrides"); String strCoreContextOverrideFile = strConfPath + DIR_OVERRIDE + FILE_CORE_CONTEXT; File fileCoreContextOverride = new File(strCoreContextOverrideFile); if (fileCoreContextOverride.exists()) { AppLogService.debug("Context file loaded : core_context"); xmlReader.loadBeanDefinitions("file:" + strCoreContextOverrideFile); } else { AppLogService.debug("No core_context override found"); } // load plugins overrides String strConfPluginsOverridePath = strConfPath + DIR_OVERRIDE_PLUGINS; File dirConfOverridePlugins = new File(strConfPluginsOverridePath); if (dirConfOverridePlugins.exists()) { String[] filesOverrideContext = dirConfOverridePlugins.list(filterContext); loadContexts(filesOverrideContext, strConfPluginsOverridePath, xmlReader); } gwac.refresh(); _context = gwac; AppLogService.info("Spring context loaded in " + (new Date().getTime() - dateBegin.getTime()) + "ms"); } catch (Exception e) { AppLogService.error("Error initializing Spring Context Service " + e.getMessage(), e); throw new LuteceInitException("Error initializing Spring Context Service", e); } } /** * Returns a name for this context * @param servletContext the servlet context * @return name for this context */ private static String getContextName(ServletContext servletContext) { String name = "lutece"; if (servletContext != null) { String contextName = servletContext.getServletContextName(); if (contextName == null) { contextName = servletContext.getContextPath(); } if (StringUtils.isNotBlank(contextName)) { name = contextName; } } return name; } /** * Loads plugins contexts. * @param filesContext context files names * @param strConfPluginsPath full path * @param xmlReader the xml reader */ private static void loadContexts(String[] filesContext, String strConfPluginsPath, XmlBeanDefinitionReader xmlReader) { for (String fileContext : filesContext) { String[] file = { "file:" + strConfPluginsPath + fileContext }; // Safe loading of plugin context file try { //_context = new ClassPathXmlApplicationContext( file, _context ); xmlReader.loadBeanDefinitions(file); AppLogService.info("Context file loaded : " + fileContext); } catch (Exception e) { AppLogService.error( "Unable to load Spring context file : " + fileContext + " - cause : " + e.getMessage(), e); } } } /** * Gets the application context * * @return The application context */ public static ApplicationContext getContext() { return _context; } /** * Returns a list of bean among all that implements a given interface or extends a given class * @param <T> The class type * @param classDef The class type * @return A list of beans */ public static <T> List<T> getBeansOfType(Class<T> classDef) { // Search the list in the cache List<T> list = _mapBeansOfType.get(classDef); if (list != null) { return new ArrayList<T>(list); } // The list is not in the cache, so we have to build it list = new ArrayList<T>(); Map<String, T> map = _context.getBeansOfType(classDef); String[] sBeanNames = map.keySet().toArray(new String[map.size()]); for (String strBeanName : sBeanNames) { String strPluginPrefix = getPrefix(strBeanName); if ((strPluginPrefix == null) || (isEnabled(strPluginPrefix))) { list.add(map.get(strBeanName)); } } _mapBeansOfType.put(classDef, new ArrayList<T>(list)); return list; } /** * Gets the prefix of the bean (supposed to be the plugin name) * @param strBeanName The bean name * @return The prefix */ private static String getPrefix(String strBeanName) { int nPos = strBeanName.indexOf("."); if (nPos > 0) { return strBeanName.substring(0, nPos); } return null; } /** * Analyze a bean prefix to tell if it matchs an activated plugin * @param strPrefix The prefix of a bean * @return True if the prefix matchs an activated plugin */ private static boolean isEnabled(String strPrefix) { Plugin plugin = PluginService.getPlugin(strPrefix); if ((plugin != null) && plugin.isInstalled()) { return true; } return false; } /** * {@inheritDoc } */ @Override public void processPluginEvent(PluginEvent event) { // Reset cache of beansOfType if a plugin is installed or uninstalled if ((event.getEventType() == PluginEvent.PLUGIN_INSTALLED) || (event.getEventType() == PluginEvent.PLUGIN_UNINSTALLED)) { if (!_mapBeansOfType.isEmpty()) { _mapBeansOfType.clear(); AppLogService.info("SpringService cache cleared due to a plugin installation change - Plugin : " + event.getPlugin().getName()); } } } /** * Closes the Spring context * @since 5.1.0 */ public static void shutdown() { if (_context != null) { ((AbstractApplicationContext) _context).close(); } } /** * Utils filename filter to identify context files */ static class ContextFileFilter implements FilenameFilter { /** * Filter filename * @param file The current file * @param strName The file name * @return true if the file is a context file otherwise false */ @Override public boolean accept(File file, String strName) { return strName.endsWith(SUFFIX_CONTEXT_FILE); } } }