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.util.externalizer;
023    
024    import java.io.IOException;
025    import java.io.ObjectInput;
026    import java.io.ObjectOutput;
027    import java.util.LinkedHashMap;
028    import java.util.Map;
029    import java.util.Map.Entry;
030    
031    public class MapExternalizer extends DefaultExternalizer {
032    
033        @Override
034        public int accept(Class<?> clazz) {
035            return Map.class.isAssignableFrom(clazz) ? 1 : -1;
036        }
037    
038        @Override
039        public void readExternal(Object o, ObjectInput in) throws IOException, ClassNotFoundException, IllegalAccessException {
040            @SuppressWarnings("unchecked")
041                    Map<Object, Object> map = (Map<Object, Object>)o;
042            int size = in.readInt();
043            for (int i = 0; i < size; i++) {
044                    Object key = in.readObject();
045                    Object value = in.readObject();
046                    map.put(key, value);
047            }
048        }
049    
050        @Override
051        public void writeExternal(Object o, ObjectOutput out) throws IOException, IllegalAccessException {
052            // Copy the map to limit the possibility of concurrent modification exceptions
053            // use a LinkedHashMap to keep order of elements
054            @SuppressWarnings("unchecked")
055                    Map<Object, Object> map = new LinkedHashMap<Object, Object>((Map<Object, Object>)o);
056            out.writeInt(map.size());
057            for (Entry<Object, Object> entry : map.entrySet()) {
058                    out.writeObject(entry.getKey());
059                    out.writeObject(entry.getValue());
060            }
061        }
062    }