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* Copyright 2009, Red Hat Middleware, LLC, and individual *
* contributors as indicated by the @authors tag. See the *
* copyright.txt in the distribution for a full listing of *
* individual contributors. *
* *
* This 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 *
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* *
* This software 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. *
* *
* You should have received a copy of the GNU Lesser General Public *
* License along with this software; if not, write to the Free *
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package org.gatein.common.util;
import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Map;
/**
* A collection of various map adapters.
*
* @author Julien Viet
* @version $Revision: 630 $
*/
public class MapAdapters
{
/** . */
private final static ArrayElementConverter stringArrayElementConverter = new ArrayElementConverter(String.class);
/** . */
private final static AbstractTypedMap.Converter stringConverter = AbstractTypedMap.Converter.identityConverter();
public static Map adapt(Map adapted, Class type)
{
if (adapted == null)
{
throw new IllegalArgumentException("Cannot adapt a null map");
}
ArrayElementConverter valueConverter = new ArrayElementConverter(type);
AbstractTypedMap.Converter keyConverter = AbstractTypedMap.Converter.identityConverter();
return new TypedMap(adapted, keyConverter, valueConverter);
}
/**
* Adapt a Map map as a Map map. The adapted map
* must not contain null string array or zero lenght string array, if the map contains such values then the
* map state is considered as not valid and {@link IllegalStateException} can be thrown when the adapted map
* is used.
*
* The adapted map is writable but does not accept null values for write operations. On a put operation
* the adapted map will receive a put operation with a string array of length one containing the provided value.
*
* @param adapted the adapted map
* @return the adapter
*/
public static Map adapt(Map adapted)
{
if (adapted == null)
{
throw new IllegalArgumentException("Cannot adapt a null map");
}
return new TypedMap(adapted, stringConverter, stringArrayElementConverter);
}
private static class ArrayElementConverter extends AbstractTypedMap.Converter
{
/** . */
private final Class type;
private ArrayElementConverter(Class type)
{
if (type == null)
{
throw new IllegalArgumentException("No null type accepted");
}
this.type = type;
}
@SuppressWarnings("unchecked")
protected T[] getInternal(T external) throws IllegalArgumentException, ClassCastException
{
if (external == null)
{
throw new NullPointerException();
}
//
T[] array = (T[])Array.newInstance(type, 1);
array[0] = external;
//
return array;
}
protected T getExternal(T[] internal) throws IllegalArgumentException, ClassCastException
{
if (internal == null)
{
throw new IllegalStateException();
}
//
if (internal.length == 0)
{
throw new IllegalStateException();
}
//
return internal[0];
}
protected boolean equals(T[] left, T[] right)
{
return Arrays.equals(left, right);
}
}
}