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 * @author Emmanuel Bourg 031 * @version $Id: SystemConfiguration.java 1842194 2018-09-27 22:24:23Z ggregory $ 032 * @since 1.1 033 */ 034public class SystemConfiguration extends MapConfiguration 035{ 036 /** The logger. */ 037 private static Log log = LogFactory.getLog(SystemConfiguration.class); 038 039 /** 040 * Create a Configuration based on the system properties. 041 * 042 * @see System#getProperties 043 */ 044 public SystemConfiguration() 045 { 046 super(System.getProperties()); 047 } 048 049 /** 050 * Sets system properties from a file specified by its file name. This is 051 * just a short cut for {@code setSystemProperties(null, fileName)}. 052 * 053 * @param fileName The name of the property file. 054 * @throws ConfigurationException if an error occurs. 055 * @since 1.6 056 */ 057 public static void setSystemProperties(final String fileName) 058 throws ConfigurationException 059 { 060 setSystemProperties(null, fileName); 061 } 062 063 /** 064 * Sets system properties from a file specified using its base path and 065 * file name. The file can either be a properties file or an XML properties 066 * file. It is loaded, and all properties it contains are added to system 067 * properties. 068 * 069 * @param basePath The base path to look for the property file. 070 * @param fileName The name of the property file. 071 * @throws ConfigurationException if an error occurs. 072 * @since 1.6 073 */ 074 public static void setSystemProperties(final String basePath, final String fileName) 075 throws ConfigurationException 076 { 077 final FileBasedConfiguration config = 078 fileName.endsWith(".xml") ? new XMLPropertiesConfiguration() 079 : new PropertiesConfiguration(); 080 081 final FileHandler handler = new FileHandler(config); 082 handler.setBasePath(basePath); 083 handler.setFileName(fileName); 084 handler.load(); 085 setSystemProperties(config); 086 } 087 088 /** 089 * Set System properties from a configuration object. 090 * @param systemConfig The configuration containing the properties to be set. 091 * @since 1.6 092 */ 093 public static void setSystemProperties(final Configuration systemConfig) 094 { 095 final Iterator<String> iter = systemConfig.getKeys(); 096 while (iter.hasNext()) 097 { 098 final String key = iter.next(); 099 final String value = (String) systemConfig.getProperty(key); 100 if (log.isDebugEnabled()) 101 { 102 log.debug("Setting system property " + key + " to " + value); 103 } 104 System.setProperty(key, value); 105 } 106 } 107 108 /** 109 * {@inheritDoc} This implementation returns a snapshot of the keys in the 110 * system properties. If another thread modifies system properties concurrently, 111 * these changes are not reflected by the iterator returned by this method. 112 */ 113 @Override 114 protected Iterator<String> getKeysInternal() 115 { 116 return System.getProperties().stringPropertyNames().iterator(); 117 } 118}