IgnoreCaseMap.java
/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.util;
import java.io.Serializable;
import java.util.Iterator;
import java.util.Map;
/**
* A {@code Map} decorator that makes the mappings in the backing map
* case insensitive
* (this is implemented by converting all keys to uppercase),
* if the keys used are {@code Strings}. If the keys
* used are not {@code String}s, it wil work as a normal
* {@code java.util.Map}.
*
* @see java.util.Map
*
* @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
*/
public class IgnoreCaseMap<V> extends AbstractDecoratedMap<String, V> implements Serializable, Cloneable {
/**
* Constructs a new empty {@code Map}.
* The backing map will be a {@link java.util.HashMap}
*/
public IgnoreCaseMap() {
super();
}
/**
* Constructs a new {@code Map} with the same key-value mappings as the
* given {@code Map}.
* The backing map will be a {@link java.util.HashMap}
* <p>
* NOTE: As the keys in the given map parameter will be converted to
* uppercase (if they are strings), any duplicate key/value pair where
* {@code key instanceof String && key.equalsIgnoreCase(otherKey)}
* is true, will be lost.
* </p>
*
* @param pMap the map whose mappings are to be placed in this map.
*/
public IgnoreCaseMap(Map<String, ? extends V> pMap) {
super(pMap);
}
/**
* Constructs a new {@code Map} with the same key-value mappings as the
* given {@code Map}.
* <p>
* NOTE: The backing map is structuraly cahnged, and it should NOT be
* accessed directly, after the wrapped map is created.
* </p>
* <p>
* NOTE: As the keys in the given map parameter will be converted to
* uppercase (if they are strings), any duplicate key/value pair where
* {@code key instanceof String && key.equalsIgnoreCase(otherKey)}
* is true, will be lost.
* </p>
*
* @param pBacking the backing map of this map. Must be either empty, or
* the same map as {@code pContents}.
* @param pContents the map whose mappings are to be placed in this map.
* May be {@code null}
*
* @throws IllegalArgumentException if {@code pBacking} is {@code null}
* @throws IllegalArgumentException if {@code pBacking} differs from
* {@code pContent} and is not empty.
*/
public IgnoreCaseMap(Map pBacking, Map<String, ? extends V> pContents) {
super(pBacking, pContents);
}
/**
* Maps the specified key to the specified value in this map.
* Note: If the key used is a string, the key will not be case-sensitive.
*
* @param pKey the map key.
* @param pValue the value.
* @return the previous value of the specified key in this map,
* or null if it did not have one.
*/
public V put(String pKey, V pValue) {
String key = (String) toUpper(pKey);
return unwrap(entries.put(key, new BasicEntry<String, V>(key, pValue)));
}
private V unwrap(Entry<String, V> pEntry) {
return pEntry != null ? pEntry.getValue() : null;
}
/**
* Returns the value to which the specified key is mapped in this
* map.
* Note: If the key used is a string, the key will not be case-sensitive.
*
* @param pKey a key in the map
* @return the value to which the key is mapped in this map; null if
* the key is not mapped to any value in this map.
*/
public V get(Object pKey) {
return unwrap(entries.get(toUpper(pKey)));
}
/**
* Removes the key (and its corresponding value) from this map. This
* method does nothing if the key is not in the map.
* Note: If the key used is a string, the key will not be case-sensitive.
*
* @param pKey the key that needs to be removed.
* @return the value to which the key had been mapped in this map,
* or null if the key did not have a mapping.
*/
public V remove(Object pKey) {
return unwrap(entries.remove(toUpper(pKey)));
}
/**
* Tests if the specified object is a key in this map.
* Note: If the key used is a string, the key will not be case-sensitive.
*
* @param pKey possible key.
* @return true if and only if the specified object is a key in this
* map, as determined by the equals method; false otherwise.
*/
public boolean containsKey(Object pKey) {
return entries.containsKey(toUpper(pKey));
}
/**
* Converts the parameter to uppercase, if it's a String.
*/
protected static Object toUpper(final Object pObject) {
if (pObject instanceof String) {
return ((String) pObject).toUpperCase();
}
return pObject;
}
protected Iterator<Entry<String, V>> newEntryIterator() {
return (Iterator) entries.entrySet().iterator();
}
protected Iterator<String> newKeyIterator() {
return entries.keySet().iterator();
}
protected Iterator<V> newValueIterator() {
return (Iterator<V>) entries.values().iterator();
}
}