001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.apache.commons.configuration2; 019 020import java.util.Iterator; 021 022import org.apache.commons.configuration2.ex.ConfigurationException; 023import org.apache.commons.configuration2.io.FileHandler; 024import org.apache.commons.logging.Log; 025import org.apache.commons.logging.LogFactory; 026 027/** 028 * A configuration based on the system properties. 029 * 030 * @since 1.1 031 */ 032public class SystemConfiguration extends MapConfiguration { 033 /** The logger. */ 034 private static final Log LOG = LogFactory.getLog(SystemConfiguration.class); 035 036 /** 037 * Create a Configuration based on the system properties. 038 * 039 * @see System#getProperties 040 */ 041 public SystemConfiguration() { 042 super(System.getProperties()); 043 } 044 045 /** 046 * Sets system properties from a file specified by its file name. This is just a short cut for 047 * {@code setSystemProperties(null, fileName)}. 048 * 049 * @param fileName The name of the property file. 050 * @throws ConfigurationException if an error occurs. 051 * @since 1.6 052 */ 053 public static void setSystemProperties(final String fileName) throws ConfigurationException { 054 setSystemProperties(null, fileName); 055 } 056 057 /** 058 * Sets system properties from a file specified using its base path and file name. The file can either be a properties 059 * file or an XML properties file. It is loaded, and all properties it contains are added to system properties. 060 * 061 * @param basePath The base path to look for the property file. 062 * @param fileName The name of the property file. 063 * @throws ConfigurationException if an error occurs. 064 * @since 1.6 065 */ 066 public static void setSystemProperties(final String basePath, final String fileName) throws ConfigurationException { 067 final FileBasedConfiguration config = fileName.endsWith(".xml") ? new XMLPropertiesConfiguration() : new PropertiesConfiguration(); 068 069 final FileHandler handler = new FileHandler(config); 070 handler.setBasePath(basePath); 071 handler.setFileName(fileName); 072 handler.load(); 073 setSystemProperties(config); 074 } 075 076 /** 077 * Sets System properties from a configuration object. 078 * 079 * @param systemConfig The configuration containing the properties to be set. 080 * @since 1.6 081 */ 082 public static void setSystemProperties(final Configuration systemConfig) { 083 final Iterator<String> iter = systemConfig.getKeys(); 084 while (iter.hasNext()) { 085 final String key = iter.next(); 086 final String value = (String) systemConfig.getProperty(key); 087 if (LOG.isDebugEnabled()) { 088 LOG.debug("Setting system property " + key + " to " + value); 089 } 090 System.setProperty(key, value); 091 } 092 } 093 094 /** 095 * {@inheritDoc} This implementation returns a snapshot of the keys in the system properties. If another thread modifies 096 * system properties concurrently, these changes are not reflected by the iterator returned by this method. 097 */ 098 @Override 099 protected Iterator<String> getKeysInternal() { 100 return System.getProperties().stringPropertyNames().iterator(); 101 } 102}