https://issues.apache.org/jira/browse/AMQ-5290

Add some utility methods that are useful for restoring past
subscriptions.

activemq-broker/src/main/java/org/apache/activemq/store/PersistenceAdapterSupport.java

@@ -16,24 +16,59 @@
  */
 package org.apache.activemq.store;
 
-import org.apache.activemq.command.ActiveMQDestination;
-import org.apache.activemq.command.ActiveMQTopic;
-import org.apache.activemq.command.SubscriptionInfo;
-
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.activemq.command.ActiveMQDestination;
+import org.apache.activemq.command.ActiveMQQueue;
+import org.apache.activemq.command.ActiveMQTopic;
+import org.apache.activemq.command.SubscriptionInfo;
+
 /**
  * Used to implement common PersistenceAdapter methods.
  */
 public class PersistenceAdapterSupport {
 
-    static public List<SubscriptionInfo> listSubscriptions(PersistenceAdapter pa, String clientId) throws IOException {
+    private static final DestinationMatcher MATCH_ALL = new AlwaysMatches();
+
+    /**
+     * Provides an interface for a Destination matching object that can be used to
+     * search for specific destinations from a persistence adapter.
+     */
+    public interface DestinationMatcher {
+
+        /**
+         * Given a Destination object, return true if the destination matches some defined
+         * search criteria, false otherwise.
+         *
+         * @param destination
+         *        the destination to inspect.
+         *
+         * @return true if the destination matches the target criteria, false otherwise.
+         */
+        boolean matches(ActiveMQDestination destination);
+
+    }
+
+    /**
+     * Searches the set of subscriptions from the given persistence adapter and returns all those
+     * that belong to the given ClientId value.
+     *
+     * @param adapter
+     *        the persistence adapter instance to search within.
+     * @param clientId
+     *        the client ID value used to filter the subscription set.
+     *
+     * @return a list of all subscriptions belonging to the given client.
+     *
+     * @throws IOException if an error occurs while listing the stored subscriptions.
+     */
+    static public List<SubscriptionInfo> listSubscriptions(PersistenceAdapter adapter, String clientId) throws IOException {
         ArrayList<SubscriptionInfo> rc = new ArrayList<SubscriptionInfo>();
-        for (ActiveMQDestination destination : pa.getDestinations()) {
+        for (ActiveMQDestination destination : adapter.getDestinations()) {
             if (destination.isTopic()) {
-                TopicMessageStore store = pa.createTopicMessageStore((ActiveMQTopic) destination);
+                TopicMessageStore store = adapter.createTopicMessageStore((ActiveMQTopic) destination);
                 for (SubscriptionInfo sub : store.getAllSubscriptions()) {
                     if (clientId == sub.getClientId() || clientId.equals(sub.getClientId())) {
                         rc.add(sub);
@@ -44,4 +79,85 @@ public class PersistenceAdapterSupport {
         return rc;
     }
 
+    /**
+     * Provides a means of querying the persistence adapter for a list of ActiveMQQueue instances.
+     *
+     * @param adapter
+     *        the persistence adapter instance to query.
+     *
+     * @return a List<ActiveMQQeue> with all the queue destinations.
+     *
+     * @throws IOException if an error occurs while reading the destinations.
+     */
+    static public List<ActiveMQQueue> listQueues(PersistenceAdapter adapter) throws IOException {
+        return listQueues(adapter, MATCH_ALL);
+    }
+
+    /**
+     * Provides a means of querying the persistence adapter for a list of ActiveMQQueue instances
+     * that match some given search criteria.
+     *
+     * @param adapter
+     *        the persistence adapter instance to query.
+     * @param matcher
+     *        the DestinationMatcher instance used to find the target destinations.
+     *
+     * @return a List<ActiveMQQeue> with all the matching destinations.
+     *
+     * @throws IOException if an error occurs while reading the destinations.
+     */
+    static public List<ActiveMQQueue> listQueues(PersistenceAdapter adapter, DestinationMatcher matcher) throws IOException {
+        ArrayList<ActiveMQQueue> rc = new ArrayList<ActiveMQQueue>();
+        for (ActiveMQDestination destination : adapter.getDestinations()) {
+            if (destination.isQueue() && matcher.matches(destination)) {
+                rc.add((ActiveMQQueue) destination);
+            }
+        }
+        return rc;
+    }
+
+    /**
+     * Provides a means of querying the persistence adapter for a list of ActiveMQTopic instances.
+     *
+     * @param adapter
+     *        the persistence adapter instance to query.
+     *
+     * @return a List<ActiveMQTopic> with all the topic destinations.
+     *
+     * @throws IOException if an error occurs while reading the destinations.
+     */
+    static public List<ActiveMQTopic> listTopics(PersistenceAdapter adapter) throws IOException {
+        return listTopics(adapter, MATCH_ALL);
+    }
+
+    /**
+     * Provides a means of querying the persistence adapter for a list of ActiveMQTopic instances
+     * that match some given search criteria.
+     *
+     * @param adapter
+     *        the persistence adapter instance to query.
+     * @param matcher
+     *        the DestinationMatcher instance used to find the target destinations.
+     *
+     * @return a List<ActiveMQTopic> with all the matching destinations.
+     *
+     * @throws IOException if an error occurs while reading the destinations.
+     */
+    static public List<ActiveMQTopic> listTopics(PersistenceAdapter adapter, DestinationMatcher matcher) throws IOException {
+        ArrayList<ActiveMQTopic> rc = new ArrayList<ActiveMQTopic>();
+        for (ActiveMQDestination destination : adapter.getDestinations()) {
+            if (destination.isTopic() && matcher.matches(destination)) {
+                rc.add((ActiveMQTopic) destination);
+            }
+        }
+        return rc;
+    }
+
+    private static class AlwaysMatches implements DestinationMatcher {
+
+        @Override
+        public boolean matches(ActiveMQDestination destination) {
+            return true;
+        }
+    }
 }