Java tutorial
/* * 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 org.apache.commons.configuration; import java.util.Iterator; /** * A configuration based on the system properties. * * @author Emmanuel Bourg * @version $Revision: 727834 $, $Date: 2008-12-18 23:16:32 +0100 (Do, 18 Dez 2008) $ * @since 1.1 */ public class SystemConfiguration extends MapConfiguration { /** * Create a Configuration based on the system properties. * * @see System#getProperties */ public SystemConfiguration() { super(System.getProperties()); } /** * The method allows system properties to be set from a property file. * @param fileName The name of the property file. * @throws Exception if an error occurs. */ public static void setSystemProperties(String fileName) throws Exception { PropertiesConfiguration config = fileName.endsWith(".xml") ? new XMLPropertiesConfiguration(fileName) : new PropertiesConfiguration(fileName); setSystemProperties(config); } /** * Set System properties from a configuration file. * @param systemConfig The configuration containing the properties to be set. */ public static void setSystemProperties(PropertiesConfiguration systemConfig) { Iterator iter = systemConfig.getKeys(); while (iter.hasNext()) { String key = (String) iter.next(); String value = (String) systemConfig.getProperty(key); System.setProperty(key, value); } } }