MapExternalizer.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.util.externalizer;

import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

public class MapExternalizer extends DefaultExternalizer {

    @Override
    public int accept(Class<?> clazz) {
        return Map.class.isAssignableFrom(clazz) ? 1 : -1;
    }

    @Override
    public void readExternal(Object o, ObjectInput in) throws IOException, ClassNotFoundException, IllegalAccessException {
    	@SuppressWarnings("unchecked")
		Map<Object, Object> map = (Map<Object, Object>)o;
    	int size = in.readInt();
    	for (int i = 0; i < size; i++) {
    		Object key = in.readObject();
    		Object value = in.readObject();
    		map.put(key, value);
    	}
    }

    @Override
    public void writeExternal(Object o, ObjectOutput out) throws IOException, IllegalAccessException {
    	// Copy the map to limit the possibility of concurrent modification exceptions
    	// use a LinkedHashMap to keep order of elements
    	@SuppressWarnings("unchecked")
		Map<Object, Object> map = new LinkedHashMap<Object, Object>((Map<Object, Object>)o);
        out.writeInt(map.size());
    	for (Entry<Object, Object> entry : map.entrySet()) {
    		out.writeObject(entry.getKey());
    		out.writeObject(entry.getValue());
    	}
    }
}