1 files changed, 96 insertions, 0 deletions
diff --git a/qpid/java/broker/src/main/java/org/apache/qpid/server/exchange/topic/TopicNormalizer.java b/qpid/java/broker/src/main/java/org/apache/qpid/server/exchange/topic/TopicNormalizer.java
new file mode 100644
index 0000000000..7e7cb6c0ae
--- /dev/null
+++ b/qpid/java/broker/src/main/java/org/apache/qpid/server/exchange/topic/TopicNormalizer.java
@@ -0,0 +1,96 @@
+/*
+ *
+ * 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;
+        }
+    }
+}