ALF-12866: WebDAV in-memory locking: configuration

* Improved configuration: config loaded from a Hazelcast XML config file.
* Config loading similar to JGroups, e.g. "protocol" substituted into config file name.
* Hazelcast instance no longer started unless the "alfresco.cluster.name" property is set.
* Current default member discovery protocol is UDP/multicast, however this is because
  this is the default set up shipped with Hazelcast - this is likely to change to TCP.



git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@34266 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/repo/cluster/HazelcastInstanceFactory.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2005-2012 Alfresco Software Limited.
+ *
+ * This file is part of Alfresco
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.alfresco.repo.cluster;
+
+import com.hazelcast.config.Config;
+import com.hazelcast.core.Hazelcast;
+import com.hazelcast.core.HazelcastInstance;
+
+/**
+ * Provides a way of lazily creating HazelcastInstances for a given configuration.
+ * The HazelcastInstance will not be created until {@link #newInstance()} is called.
+ * <p>
+ * An intermediary class such as this is required in order to avoid starting
+ * Hazelcast instances when clustering is not configured/required. Otherwise
+ * simply by defining a HazelcastInstance bean clustering would spring into life.
+ * 
+ * @author Matt Ward
+ */
+public class HazelcastInstanceFactory
+{
+    public Config config;
+
+    public HazelcastInstance newInstance()
+    {
+        return Hazelcast.newHazelcastInstance(config);
+    }
+
+    /**
+     * @param config the config to set
+     */
+    public void setConfig(Config config)
+    {
+        this.config = config;
+    }
+}