/*
*
* 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.qpid.server.exchange.topic;
import org.apache.qpid.framing.AMQShortString;
import org.apache.qpid.framing.AMQShortStringTokenizer;
import org.apache.qpid.server.exchange.TopicExchange;
import java.util.List;
import java.util.ArrayList;
public class TopicNormalizer
{
private static final byte TOPIC_SEPARATOR = (byte)'.';
private static final byte HASH_BYTE = (byte)'#';
private static final byte STAR_BYTE = (byte)'*';
private static final AMQShortString TOPIC_SEPARATOR_AS_SHORTSTRING = new AMQShortString(".");
private static final AMQShortString AMQP_STAR_TOKEN = new AMQShortString("*");
private static final AMQShortString AMQP_HASH_TOKEN = new AMQShortString("#");
public static AMQShortString normalize(AMQShortString routingKey)
{
if(routingKey == null)
{
return AMQShortString.EMPTY_STRING;
}
else if(!(routingKey.contains(HASH_BYTE) || routingKey.contains(STAR_BYTE)))
{
return routingKey;
}
else
{
AMQShortStringTokenizer routingTokens = routingKey.tokenize(TOPIC_SEPARATOR);
List<AMQShortString> subscriptionList = new ArrayList<AMQShortString>();
while (routingTokens.hasMoreTokens())
{
subscriptionList.add(routingTokens.nextToken());
}
int size = subscriptionList.size();
for (int index = 0; index < size; index++)
{
// if there are more levels
if ((index + 1) < size)
{
if (subscriptionList.get(index).equals(AMQP_HASH_TOKEN))
{
if (subscriptionList.get(index + 1).equals(AMQP_HASH_TOKEN))
{
// we don't need #.# delete this one
subscriptionList.remove(index);
size--;
// redo this normalisation
index--;
}
if (subscriptionList.get(index + 1).equals(AMQP_STAR_TOKEN))
{
// we don't want #.* swap to *.#
// remove it and put it in at index + 1
subscriptionList.add(index + 1, subscriptionList.remove(index));
}
}
} // if we have more levels
}
AMQShortString normalizedString = AMQShortString.join(subscriptionList, TOPIC_SEPARATOR_AS_SHORTSTRING);
return normalizedString;
}
}
}