Java tutorial
/* * Copyright 2004-2005 Germinus XXI * * 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 org.gcube.common.homelibrary.util.config.easyconf; import org.apache.commons.configuration.AbstractFileConfiguration; import org.apache.commons.configuration.CompositeConfiguration; import org.apache.commons.configuration.Configuration; import org.apache.commons.configuration.FileConfiguration; import org.apache.commons.configuration.PropertiesConfiguration; import org.apache.commons.configuration.SubsetConfiguration; import org.apache.commons.configuration.SystemConfiguration; import org.apache.commons.configuration.reloading.FileChangedReloadingStrategy; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import java.net.URL; import java.util.*; /** * Provides configuration properties from several sources making distintion * from: * <ul> * <li>Base properties specific to the current component * <li>Global properties which may be prefixed * <li>System properties (so that they are available as variables to the other * property files) * </ul> * It also knows the source the a property to offer user information. * * @author jferrer */ public class AggregatedProperties extends CompositeConfiguration { private static final Log log = LogFactory.getLog(AggregatedProperties.class); private CompositeConfiguration baseConf = new CompositeConfiguration(); private CompositeConfiguration globalConf = new CompositeConfiguration(); private SystemConfiguration systemConfiguration = new SystemConfiguration(); private Configuration prefixedSystemConfiguration = new SubsetConfiguration(systemConfiguration, getPrefix(), null); private String componentName; private String companyId; private List<String> loadedSources = new ArrayList<String>(); private boolean baseConfigurationLoaded = false; public AggregatedProperties(String companyId, String componentName) { this.componentName = componentName; this.companyId = companyId; } /** * Look for the property in environment, global and base configuration, in * this order * * @param key * @return */ @Override public Object getProperty(String key) { Object value = null; if (value == null) { // value = prefixedSystemConfiguration.getProperty(key); value = System.getProperty(getPrefix() + key); } if (value == null) { value = globalConf.getProperty(getPrefix() + key); } if (value == null) { value = globalConf.getProperty(key); } if (value == null) { value = baseConf.getProperty(key); } if (value == null) { value = super.getProperty(key); } if (value == null) { // value = systemConfiguration.getProperty(key); value = System.getProperty(key); } if ((value == null) && (key.equals(Conventions.COMPANY_ID_PROPERTY))) { value = companyId; } if ((value == null) && (key.equals(Conventions.COMPONENT_NAME_PROPERTY))) { value = componentName; } return value; } private String getPrefix() { return componentName + Conventions.PREFIX_SEPARATOR; } public void addBaseFileName(String fileName) { Configuration conf = addPropertiesSource(fileName, baseConf); if ((conf != null) && (!conf.isEmpty())) { baseConfigurationLoaded = true; } } public void addGlobalFileName(String fileName) { addPropertiesSource(fileName, globalConf); } /** * Read the given source of properties and add it to the composite * configuration. The added configuration will be returned. If it is not * found null will be returned. */ private Configuration addPropertiesSource(String sourceName, CompositeConfiguration loadedConf) { try { Configuration newConf; if (DatasourceURL.isDatasource(sourceName)) { newConf = addDatasourceProperties(sourceName); } else if (JndiURL.isJndi(sourceName)) { newConf = addJndiProperties(sourceName); } else { newConf = addFileProperties(sourceName, loadedConf); } if (newConf != null) { loadedConf.addConfiguration(newConf); super.addConfiguration(newConf); if (newConf instanceof AbstractFileConfiguration) { loadedSources.add(((AbstractFileConfiguration) newConf).getURL().toString()); } else { loadedSources.add(sourceName); } } return newConf; } catch (Exception ignore) { if (log.isDebugEnabled()) { log.debug("Configuration source " + sourceName + " ignored"); } return null; } } private Configuration addFileProperties(String fileName, CompositeConfiguration loadedConf) throws ConfigurationException { try { FileConfiguration newConf = new PropertiesConfiguration(fileName); URL fileURL = newConf.getURL(); log.debug("Adding file: " + fileURL); Long delay = getReloadDelay(loadedConf, newConf); if (delay != null) { FileChangedReloadingStrategy reloadingStrategy = new FileConfigurationChangedReloadingStrategy(); if (log.isDebugEnabled()) { log.debug("File " + fileURL + " will be reloaded every " + delay + " seconds"); } long milliseconds = delay.longValue() * 1000; reloadingStrategy.setRefreshDelay(milliseconds); newConf.setReloadingStrategy(reloadingStrategy); } addIncludedPropertiesSources(newConf, loadedConf); return newConf; } catch (org.apache.commons.configuration.ConfigurationException e) { if (log.isDebugEnabled()) { log.debug("Configuration source " + fileName + " ignored"); } return null; } } private Long getReloadDelay(CompositeConfiguration loadedConf, FileConfiguration newConf) { Long delay = newConf.getLong(Conventions.RELOAD_DELAY_PROPERTY, null); if (delay == null) { delay = loadedConf.getLong(Conventions.RELOAD_DELAY_PROPERTY, null); } return delay; } private Configuration addDatasourceProperties(String datasourcePath) { DatasourceURL dsUrl = new DatasourceURL(datasourcePath, companyId, componentName, DatasourceURL.PROPERTIES_TABLE); return dsUrl.getConfiguration(); } private Configuration addJndiProperties(String sourcePath) { JndiURL jndiUrl = new JndiURL(sourcePath, companyId, componentName); return jndiUrl.getConfiguration(); } private void addIncludedPropertiesSources(Configuration newConf, CompositeConfiguration loadedConf) { CompositeConfiguration tempConf = new CompositeConfiguration(); tempConf.addConfiguration(prefixedSystemConfiguration); tempConf.addConfiguration(newConf); tempConf.addConfiguration(systemConfiguration); tempConf.addProperty(Conventions.COMPANY_ID_PROPERTY, companyId); tempConf.addProperty(Conventions.COMPONENT_NAME_PROPERTY, componentName); String[] fileNames = tempConf.getStringArray(Conventions.INCLUDE_PROPERTY); for (int i = fileNames.length - 1; i >= 0; i--) { String iteratedFileName = fileNames[i]; addPropertiesSource(iteratedFileName, loadedConf); } } public List<String> loadedSources() { return loadedSources; } public boolean hasBaseConfiguration() { return baseConfigurationLoaded; } public String getComponentName() { return componentName; } }