001/*
002  GRANITE DATA SERVICES
003  Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004
005  This file is part of Granite Data Services.
006
007  Granite Data Services is free software; you can redistribute it and/or modify
008  it under the terms of the GNU Library General Public License as published by
009  the Free Software Foundation; either version 2 of the License, or (at your
010  option) any later version.
011
012  Granite Data Services is distributed in the hope that it will be useful, but
013  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015  for more details.
016
017  You should have received a copy of the GNU Library General Public License
018  along with this library; if not, see <http://www.gnu.org/licenses/>.
019*/
020
021package org.granite.messaging.amf.io.convert;
022
023import java.lang.reflect.Type;
024import java.lang.reflect.TypeVariable;
025
026import org.granite.util.TypeUtil;
027
028/**
029 * @author Franck WOLFF
030 */
031public abstract class Converter {
032
033    protected final Converters converters;
034
035    /**
036     * Build a new Converter instance.
037     *
038     * @param converters a {@link Converters} instance (must be not null).
039     * @throws NullPointerException (if converters is null).
040     */
041    public Converter(Converters converters) {
042        if (converters == null)
043            throw new NullPointerException("converters parameter cannot be null");
044        this.converters = converters;
045    }
046
047    /**
048     * Tells if the supplied object may be converted to the supplied target type by
049     * this converter.
050     *
051     * @param value the object to be converted.
052     * @param targetType the target type.
053     * @return true if this converter can convert o to the target type, false otherwise.
054     */
055    public final boolean canConvert(Object value, Type targetType) {
056        if (targetType instanceof TypeVariable<?>)
057                targetType = TypeUtil.getBoundType((TypeVariable<?>)targetType);
058        return internalCanConvert(value, targetType);
059    }
060    
061    protected abstract boolean internalCanConvert(Object value, Type targetType);
062
063    /**
064     * Converts the supplied object to the supplied target type.
065     *
066     * @param value the object to be converted.
067     * @param targetType the target type.
068     * @return the converted object.
069     */
070    public final Object convert(Object value, Type targetType) {
071        if (targetType instanceof TypeVariable<?>)
072                targetType = TypeUtil.getBoundType((TypeVariable<?>)targetType);
073        return internalConvert(value, targetType);
074    }
075
076    protected abstract Object internalConvert(Object value, Type targetType);
077}