Map2Map.java

/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2015 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *   Granite Data Services 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 the License, or (at your option) any later version.
 *
 *   Granite Data Services 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 library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 *   USA, or see <http://www.gnu.org/licenses/>.
 */
package org.granite.messaging.amf.io.convert.impl;

import java.lang.reflect.Type;
import java.lang.reflect.WildcardType;
import java.util.Map;
import java.util.Map.Entry;

import org.granite.messaging.amf.io.convert.Converter;
import org.granite.messaging.amf.io.convert.Converters;
import org.granite.messaging.amf.io.convert.IllegalConverterArgumentException;
import org.granite.util.TypeUtil;
import org.granite.util.MapUtil;

/**
 * @author Franck WOLFF
 */
public class Map2Map extends Converter {

    public Map2Map(Converters converters) {
        super(converters);
    }

    @Override
	protected boolean internalCanConvert(Object value, Type targetType) {

        Type[] targetComponentTypes = MapUtil.getComponentTypes(targetType);
        if (targetComponentTypes == null)
            return false; // not a map.

        if (value == null)
            return true;

        if (!(value instanceof Map<?, ?>))
            return false;

        Type keyType = targetComponentTypes[0];
        Type valueType = targetComponentTypes[1];

        if ((keyType.equals(Object.class) || keyType instanceof WildcardType) &&
            (valueType.equals(Object.class) || valueType instanceof WildcardType))
            return true;

        Converter keyConverter = null;
        Converter valueConverter = null;
        for (Map.Entry<?, ?> item : ((Map<?, ?>)value).entrySet()) {

            if (keyConverter == null)
                keyConverter = converters.getConverter(item.getKey(), keyType);
            else if (!keyConverter.canConvert(item.getKey(), keyType))
                keyConverter = converters.getConverter(item.getKey(), keyType);
            if (keyConverter == null)
                return false;

            if (valueConverter == null)
                valueConverter = converters.getConverter(item.getValue(), valueType);
            else if (!valueConverter.canConvert(item.getValue(), valueType))
                valueConverter = converters.getConverter(item.getValue(), valueType);
            if (valueConverter == null)
                return false;
        }

        return true;
    }

    @Override
	protected Object internalConvert(Object value, Type targetType) {

        if (value == null)
            return null;

        if (value instanceof Map<?, ?>) {
            Map<?, ?> map = (Map<?, ?>)value;

            Type[] targetComponentTypes = MapUtil.getComponentTypes(targetType);
            if (targetComponentTypes != null) {
                Type keyType = targetComponentTypes[0];
                Type valueType = targetComponentTypes[1];

                Class<?> targetClass = TypeUtil.classOfType(targetType);
                if (targetClass.isInstance(value) &&
                    (keyType.equals(Object.class) || keyType instanceof WildcardType) &&
                    (valueType.equals(Object.class) || valueType instanceof WildcardType))
                    return value;
                
                // Check if all keys and values are compatible
                if (targetClass.isInstance(value)) {
                	Class<?> keyClass = TypeUtil.classOfType(keyType);
                	Class<?> valueClass = TypeUtil.classOfType(valueType);
                	
                	boolean compatible = true;                	
                	for (Entry<?, ?> entry : ((Map<?, ?>)value).entrySet()) {
                		if (!keyClass.isInstance(entry.getKey()) || !valueClass.isInstance(entry.getValue())) {
                			compatible = false;
                			break;
                		}
                	}
                	if (compatible)
                		return value;
                }
                
                Map<Object, Object> targetInstance = null;
                try {
                    targetInstance = MapUtil.newMap(targetClass, map.size());
                } catch (Exception e) {
                    throw new IllegalConverterArgumentException(this, value, targetType, e);
                }

                Converter keyConverter = null;
                Converter valueConverter = null;
                for (Map.Entry<?, ?> item : ((Map<?, ?>)value).entrySet()) {

                    if (keyConverter == null)
                        keyConverter = converters.getConverter(item.getKey(), keyType);
                    else if (!keyConverter.canConvert(item.getKey(), keyType))
                        keyConverter = converters.getConverter(item.getKey(), keyType);
                    if (keyConverter == null)
                        throw new IllegalConverterArgumentException(this, value, targetType);

                    if (valueConverter == null)
                        valueConverter = converters.getConverter(item.getValue(), valueType);
                    else if (!valueConverter.canConvert(item.getValue(), valueType))
                        valueConverter = converters.getConverter(item.getValue(), valueType);
                    if (valueConverter == null)
                        throw new IllegalConverterArgumentException(this, value, targetType);

                    targetInstance.put(
                        keyConverter.convert(item.getKey(), keyType),
                        valueConverter.convert(item.getValue(), valueType)
                    );
                }

                return targetInstance;
            }
        }

        throw new IllegalConverterArgumentException(this, value, targetType);
    }
}