001/**
002 *   GRANITE DATA SERVICES
003 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 *   This file is part of the Granite Data Services Platform.
006 *
007 *   Granite Data Services is free software; you can redistribute it and/or
008 *   modify it under the terms of the GNU Lesser General Public
009 *   License as published by the Free Software Foundation; either
010 *   version 2.1 of the License, or (at your option) any later version.
011 *
012 *   Granite Data Services is distributed in the hope that it will be useful,
013 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
014 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015 *   General Public License for more details.
016 *
017 *   You should have received a copy of the GNU Lesser General Public
018 *   License along with this library; if not, write to the Free Software
019 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020 *   USA, or see <http://www.gnu.org/licenses/>.
021 */
022package org.granite.messaging.amf.io.convert;
023
024import java.lang.reflect.Type;
025import java.lang.reflect.TypeVariable;
026
027import org.granite.util.TypeUtil;
028
029/**
030 * @author Franck WOLFF
031 */
032public abstract class Converter {
033
034    protected final Converters converters;
035
036    /**
037     * Build a new Converter instance.
038     *
039     * @param converters a {@link Converters} instance (must be not null).
040     * @throws NullPointerException (if converters is null).
041     */
042    public Converter(Converters converters) {
043        if (converters == null)
044            throw new NullPointerException("converters parameter cannot be null");
045        this.converters = converters;
046    }
047
048    /**
049     * Tells if the supplied object may be converted to the supplied target type by
050     * this converter.
051     *
052     * @param value the object to be converted.
053     * @param targetType the target type.
054     * @return true if this converter can convert o to the target type, false otherwise.
055     */
056    public final boolean canConvert(Object value, Type targetType) {
057        if (targetType instanceof TypeVariable<?>)
058                targetType = TypeUtil.getBoundType((TypeVariable<?>)targetType);
059        return internalCanConvert(value, targetType);
060    }
061    
062    protected abstract boolean internalCanConvert(Object value, Type targetType);
063
064    /**
065     * Converts the supplied object to the supplied target type.
066     *
067     * @param value the object to be converted.
068     * @param targetType the target type.
069     * @return the converted object.
070     */
071    public final Object convert(Object value, Type targetType) {
072        if (targetType instanceof TypeVariable<?>)
073                targetType = TypeUtil.getBoundType((TypeVariable<?>)targetType);
074        return internalConvert(value, targetType);
075    }
076
077    protected abstract Object internalConvert(Object value, Type targetType);
078}