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/*
* 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.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
/**
*
* A Map based Configuration.
*
*
* This implementation of the Configuration interface is
* initialized with a java.util.Map. The methods of the
* Configuration interface are implemented on top of the content of
* this map. The following storage scheme is used:
*
*
* Property keys are directly mapped to map keys, i.e. the
* getProperty() method directly performs a get() on
* the map. Analogously, setProperty() or
* addProperty() operations write new data into the map. If a value
* is added to an existing property, a java.util.List is created,
* which stores the values of this property.
*
*
* An important use case of this class is to treat a map as a
* Configuration allowing access to its data through the richer
* interface. This can be a bit problematic in some cases because the map may
* contain values that need not adhere to the default storage scheme used by
* typical configuration implementations, e.g. regarding lists. In such cases
* care must be taken when manipulating the data through the
* Configuration interface, e.g. by calling
* addProperty(); results may be different than expected.
*
*
* An important point is the handling of list delimiters: If delimiter parsing
* is enabled (which it is per default), getProperty() checks
* whether the value of a property is a string and whether it contains the list
* delimiter character. If this is the case, the value is split at the delimiter
* resulting in a list. This split operation typically also involves trimming
* the single values as the list delimiter character may be surrounded by
* whitespace. Trimming can be disabled with the
* {@link #setTrimmingDisabled(boolean)} method. The whole list splitting
* behavior can be disabled using the
* {@link #setDelimiterParsingDisabled(boolean)} method.
*
*
* Notice that list splitting is only performed for single string values. If a
* property has multiple values, the single values are not split even if they
* contain the list delimiter character.
*
*
* As the underlying Map is directly used as store of the property
* values, the thread-safety of this Configuration implementation
* depends on the map passed to the constructor.
*
*
* @author Emmanuel Bourg
* @version $Revision: 763367 $, $Date: 2009-04-08 21:56:10 +0200 (Mi, 08. Apr 2009) $
* @since 1.1
*/
public class MapConfiguration extends AbstractConfiguration implements Cloneable
{
/** The Map decorated by this configuration. */
protected Map map;
/** A flag whether trimming of property values should be disabled.*/
private boolean trimmingDisabled;
/**
* Create a Configuration decorator around the specified Map. The map is
* used to store the configuration properties, any change will also affect
* the Map.
*
* @param map the map
*/
public MapConfiguration(Map map)
{
this.map = map;
}
/**
* Return the Map decorated by this configuration.
*
* @return the map this configuration is based onto
*/
public Map getMap()
{
return map;
}
/**
* Returns the flag whether trimming of property values is disabled.
*
* @return true if trimming of property values is disabled;
* false otherwise
* @since 1.7
*/
public boolean isTrimmingDisabled()
{
return trimmingDisabled;
}
/**
* Sets a flag whether trimming of property values is disabled. This flag is
* only evaluated if list splitting is enabled. Refer to the header comment
* for more information about list splitting and trimming.
*
* @param trimmingDisabled a flag whether trimming of property values should
* be disabled
* @since 1.7
*/
public void setTrimmingDisabled(boolean trimmingDisabled)
{
this.trimmingDisabled = trimmingDisabled;
}
public Object getProperty(String key)
{
Object value = map.get(key);
if ((value instanceof String) && (!isDelimiterParsingDisabled()))
{
List list = PropertyConverter.split((String) value, getListDelimiter(), !isTrimmingDisabled());
return list.size() > 1 ? list : list.get(0);
}
else
{
return value;
}
}
protected void addPropertyDirect(String key, Object value)
{
Object previousValue = getProperty(key);
if (previousValue == null)
{
map.put(key, value);
}
else if (previousValue instanceof List)
{
// the value is added to the existing list
((List) previousValue).add(value);
}
else
{
// the previous value is replaced by a list containing the previous value and the new value
List list = new ArrayList();
list.add(previousValue);
list.add(value);
map.put(key, list);
}
}
public boolean isEmpty()
{
return map.isEmpty();
}
public boolean containsKey(String key)
{
return map.containsKey(key);
}
protected void clearPropertyDirect(String key)
{
map.remove(key);
}
public Iterator getKeys()
{
return map.keySet().iterator();
}
/**
* Returns a copy of this object. The returned configuration will contain
* the same properties as the original. Event listeners are not cloned.
*
* @return the copy
* @since 1.3
*/
public Object clone()
{
try
{
MapConfiguration copy = (MapConfiguration) super.clone();
copy.clearConfigurationListeners();
copy.map = (Map) ConfigurationUtils.clone(map);
return copy;
}
catch (CloneNotSupportedException cex)
{
// cannot happen
throw new ConfigurationRuntimeException(cex);
}
}
}