/**
* Copyright 2010 Google Inc.
*
* Licensed 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 com.google.wave.api.data.converter;
import com.google.wave.api.ProtocolVersion;
import java.util.Map.Entry;
import java.util.NavigableMap;
/**
* A simple utility class that manages the {@link EventDataConverter} for
* various protocol versions.
*
*/
public class EventDataConverterManager {
/** A map of protocol version to {@link EventDataConverter}. */
private final NavigableMap<ProtocolVersion, EventDataConverter> eventDataConverters;
/**
* Constructor.
*
* @param eventDataConverters a map of {@link EventDataConverter}.
*/
public EventDataConverterManager(
NavigableMap<ProtocolVersion, EventDataConverter> eventDataConverters) {
this.eventDataConverters = eventDataConverters;
}
/**
* Returns an instance of an {@link EventDataConverter} for the given
* protocol version.
*
* @param protocolVersion the protocol version.
* @return an instance of an {@link EventDataConverter}, or {@code null} if
* there is no converter for the given version.
*/
public EventDataConverter getEventDataConverter(ProtocolVersion protocolVersion) {
// Get the latest instance of {@link EventDataConverter} for a protocol
// version that is less than or equal to the given version, as not every
// protocol version will have a versioned {@link EventDataConverter}.
Entry<ProtocolVersion, EventDataConverter> entry = eventDataConverters.floorEntry(
protocolVersion);
if (entry == null) {
return null;
}
return entry.getValue();
}
}