Mega Code Archive
An object that maps keys to values, and values back to keys
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/*
* Copyright (c) 2006-2008 Chris Smith, Shane Mc Cormack, Gregory Holmes
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
//package com.dmdirc.util;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* An object that maps keys to values, and values back to keys. Currently
* does no checking for duplicates. Does not allow null values.
*
* @param <A> The first type of data to be mapped
* @param <B> The second type of data to be mapped
* @author chris
*/
public class DoubleMap<A,B> {
/** The keys in this map. */
protected final List<A> keys = new ArrayList<A>();
/** The values in this map. */
protected final List<B> values = new ArrayList<B>();
/**
* Adds the specified pair to this map.
*
* @param key The key for the map
* @param value The value for the map
*/
public void put(final A key, final B value) {
if (key == null || value == null) {
throw new NullPointerException();
}
keys.add(key);
values.add(value);
}
/**
* Retrieves the value associated with the specified key.
*
* @param key The key to search for
* @return The value of the specified key
*/
public B getValue(final A key) {
return values.get(keys.indexOf(key));
}
/**
* Retrieves the key associated with the specified value.
*
* @param value The value to search for
* @return The key of the specified value
*/
public A getKey(final B value) {
return keys.get(values.indexOf(value));
}
/**
* Retrieves the set of keys in this double map.
*
* @return This map's key set
*/
public Set<A> keySet() {
return new HashSet<A>(keys);
}
/**
* Retrieves the set of values in this double map.
*
* @return This map's value set
*/
public Set<B> valueSet() {
return new HashSet<B>(values);
}
}
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