org.apache.wicket.util.collections.MultiMap Maven / Gradle / Ivy
/*
* 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.wicket.util.collections;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* A simple multimap
*
* @author igor
* @param
* @param
*/
public class MultiMap extends HashMap>
{
private static final long serialVersionUID = 1L;
/**
* Constructor
*
* @see HashMap#HashMap()
*/
public MultiMap()
{
}
/**
* Constructor
*
* @param initialCapacity
* @param loadFactor
*
* @see HashMap#HashMap(int, float)
*/
public MultiMap(final int initialCapacity, final float loadFactor)
{
super(initialCapacity, loadFactor);
}
/**
* Constructor
*
* @param initialCapacity
*
* @see HashMap#HashMap(int)
*/
public MultiMap(final int initialCapacity)
{
super(initialCapacity);
}
/**
* Constructor
*
* @param m
*
* @see HashMap#HashMap(Map)
*/
public MultiMap(final Map> m)
{
super(m);
}
/**
* Adds value to the specified key
*
* @param key
* @param value
*/
public void addValue(final K key, final V value)
{
List list = get(key);
if (list == null)
{
list = new ArrayList<>(1);
put(key, list);
}
list.add(value);
}
/**
* Removes value from the specified key
*
* @param key
* @param value
*/
public void removeValue(final K key, final V value)
{
List list = get(key);
if (list != null)
{
list.remove(value);
}
}
/**
* Replaces all existing values with the specified value. If no values exist for the key the
* value will be added.
*
* @param key
* @param value
*/
public void replaceValues(final K key, final V value)
{
List list = get(key);
if (list != null)
{
list.clear();
list.add(value);
}
else
{
addValue(key, value);
}
}
/**
* Gets the first value in the value list
*
* @param key
* @return first value
*/
public V getFirstValue(final K key)
{
List list = get(key);
if ((list != null) && !list.isEmpty())
{
return list.get(0);
}
return null;
}
}