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     */
022    package org.granite.messaging.amf.io.convert;
023    
024    import java.lang.reflect.Type;
025    import java.lang.reflect.TypeVariable;
026    
027    import org.granite.util.TypeUtil;
028    
029    /**
030     * @author Franck WOLFF
031     */
032    public 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    }