/*

  * 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);

         }

     }

 }