1 files changed, 92 insertions, 0 deletions
diff --git a/qpid/java/broker-core/src/main/java/org/apache/qpid/server/exchange/topic/TopicNormalizer.java b/qpid/java/broker-core/src/main/java/org/apache/qpid/server/exchange/topic/TopicNormalizer.java
new file mode 100644
index 0000000000..e45d6a539d
--- /dev/null
+++ b/qpid/java/broker-core/src/main/java/org/apache/qpid/server/exchange/topic/TopicNormalizer.java
@@ -0,0 +1,92 @@
+/*
+ *
+ * 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 java.util.Arrays;
+import java.util.Iterator;
+import java.util.ArrayList;
+import java.util.List;
+
+public class TopicNormalizer
+{
+
+    private static final String STAR_TOKEN = "*";
+    private static final String HASH_TOKEN = "#";
+    private static final String SEPARATOR = ".";
+
+
+    private TopicNormalizer()
+    {
+    }
+
+    public static String normalize(String routingKey)
+    {
+        if(routingKey == null)
+        {
+            return "";
+        }
+        else if(!(routingKey.contains(HASH_TOKEN) || !routingKey.contains(STAR_TOKEN)))
+        {
+            return routingKey;
+        }
+        else
+        {
+            List<String> subscriptionList = new ArrayList<String>(Arrays.asList(routingKey.split("\\.")));
+
+            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(HASH_TOKEN))
+                    {
+                        if (subscriptionList.get(index + 1).equals(HASH_TOKEN))
+                        {
+                            // we don't need #.# delete this one
+                            subscriptionList.remove(index);
+                            size--;
+                            // redo this normalisation
+                            index--;
+                        }
+
+                        if (subscriptionList.get(index + 1).equals(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
+            }
+
+            Iterator<String> iter = subscriptionList.iterator();
+            StringBuilder builder = new StringBuilder(iter.next());
+            while(iter.hasNext())
+            {
+                builder.append(SEPARATOR).append(iter.next());
+            }
+            return builder.toString();
+        }
+    }
+
+}