/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.brooklyn.util.core.xstream;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.thoughtworks.xstream.converters.MarshallingContext;
import com.thoughtworks.xstream.converters.UnmarshallingContext;
import com.thoughtworks.xstream.core.ReferencingMarshallingContext;
import com.thoughtworks.xstream.io.ExtendedHierarchicalStreamWriterHelper;
import com.thoughtworks.xstream.io.HierarchicalStreamReader;
import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
import com.thoughtworks.xstream.mapper.Mapper;
/** equivalent to super, but cleaner methods, overridable, logging, and some retries */
public class MapConverter extends com.thoughtworks.xstream.converters.collections.MapConverter {
private static final Logger log = LoggerFactory.getLogger(MapConverter.class);
public MapConverter(Mapper mapper) {
super(mapper);
}
@SuppressWarnings({ "rawtypes" })
public void marshal(Object source, HierarchicalStreamWriter writer, MarshallingContext context) {
Map map = (Map) source;
try {
for (Iterator iterator = map.entrySet().iterator(); iterator.hasNext();) {
Map.Entry entry = (Map.Entry) iterator.next();
marshalEntry(writer, context, entry);
}
} catch (ConcurrentModificationException e) {
log.debug("Map "
// seems there is no non-deprecated way to get the path...
+ (context instanceof ReferencingMarshallingContext ? "at "+((ReferencingMarshallingContext)context).currentPath() : "")
+ "["+source+"] modified while serializing; will fail, and retry may be attempted");
throw e;
// would be nice to attempt to re-serialize being slightly more defensive, as code below;
// but the code above may have written partial data so that is dangerous, we could have corrupted output.
// if we could mark and restore in the output stream then we could do this below (but we don't have that in our stream),
// or we could try this copying code in the first instance (but that's slow);
// error is rare most of the time (e.g. attribute being updated) so we bail on this whole attempt
// and simply try serializing the map-owner (e.g. an entity) again.
// ImmutableList entries = ImmutableList.copyOf(map.entrySet());
// for (Iterator iterator = entries.iterator(); iterator.hasNext();) {
// Map.Entry entry = (Map.Entry) iterator.next();
// marshalEntry(writer, context, entry);
// }
}
}
protected String getEntryNodeName() { return mapper().serializedClass(Map.Entry.class); }
protected void marshalEntry(HierarchicalStreamWriter writer, MarshallingContext context, Map.Entry entry) {
ExtendedHierarchicalStreamWriterHelper.startNode(writer, getEntryNodeName(), Map.Entry.class);
writeItem(entry.getKey(), context, writer);
writeItem(entry.getValue(), context, writer);
writer.endNode();
}
protected void populateMap(HierarchicalStreamReader reader, UnmarshallingContext context, Map map) {
while (reader.hasMoreChildren()) {
reader.moveDown();
unmarshalEntry(reader, context, map);
reader.moveUp();
}
}
protected void unmarshalEntry(HierarchicalStreamReader reader, UnmarshallingContext context, Map map) {
reader.moveDown();
Object key = readItem(reader, context, map);
reader.moveUp();
reader.moveDown();
Object value = readItem(reader, context, map);
reader.moveUp();
map.put(key, value);
}
}