plantuml/src/jcckit/util/ConfigParametersBasedConfig...

75 lines
2.7 KiB
Java

/*
* Copyright 2003-2004, Franz-Josef Elmer, All rights reserved
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details
* (http://www.gnu.org/copyleft/lesser.html).
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package jcckit.util;
/**
* An implementation of {@link ConfigData} based on two instances of
* {@link ConfigParameters}. The second one serves as a set of
* default parameters. It will be used if the first one has not the requested
* key-value pair.
*
* @author Franz-Josef Elmer
*/
public class ConfigParametersBasedConfigData implements ConfigData {
private ConfigParameters _config;
private ConfigParameters _defaultConfig;
/**
* Creates an instance.
* @param config A set of key-value pairs.
* @param defaultConfig The default set of key-value pairs.
*/
public ConfigParametersBasedConfigData(ConfigParameters config,
ConfigParameters defaultConfig) {
_config = config;
_defaultConfig = defaultConfig;
}
/**
* Returns the full key.
* @param key A (relative) key. <tt>null</tt> is not allowed.
* @return the full key including path.
*/
public String getFullKey(String key) {
return _config.getFullKey(key);
}
/**
* Returns the value associated with this key.
* @param key The relative key. <tt>null</tt> is not allowed.
* @return the associated value. Will be <tt>null</tt> if no value exists
* for <tt>key</tt>.
*/
public String get(String key) {
String value = _config.get(key, null);
return value == null ? _defaultConfig.get(key, null) : value;
}
/**
* Returns the <tt>ConfigData</tt> object associated with this key.
* @param key The relative key. <tt>null</tt> is not allowed.
* @return the associated value. Will never return <tt>null</tt>.
* Instead an empty <tt>ConfigData</tt> is returned.
*/
public ConfigData getNode(String key) {
return new ConfigParametersBasedConfigData(_config.getNode(key),
_defaultConfig.getNode(key));
}
}