Consolidate code clones in Persistent* tests.

Change-Id: Ib46e300a3b3af36eab923e43f1b1faee7b1e2d38
diff --git a/core/store/persistence/src/test/java/org/onosproject/persistence/impl/MapDBTest.java b/core/store/persistence/src/test/java/org/onosproject/persistence/impl/MapDBTest.java
new file mode 100644
index 0000000..ac5d353
--- /dev/null
+++ b/core/store/persistence/src/test/java/org/onosproject/persistence/impl/MapDBTest.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed 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.onosproject.persistence.impl;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.rules.TemporaryFolder;
+import org.mapdb.DB;
+import org.mapdb.DBMaker;
+
+/**
+ * Utils for Tests using MapDB.
+ */
+public abstract class MapDBTest {
+
+    @Rule
+    public TemporaryFolder tmpFolder = new TemporaryFolder();
+
+    protected DB fakeDB = null;
+
+    /**
+     * Set up the database.
+     *
+     * @throws Exception if instantiation fails
+     */
+    @Before
+    public void setUpDB() throws Exception {
+        // Creates a db
+        fakeDB = DBMaker
+                .newFileDB(tmpFolder.newFile())
+                .asyncWriteEnable()
+                .commitFileSyncDisable()
+                .mmapFileEnableIfSupported()
+                .closeOnJvmShutdown()
+                .deleteFilesAfterClose()
+                .make();
+    }
+
+    /**
+     * Closes the database.
+     *
+     * @throws Exception if shutdown fails
+     */
+    @After
+    public void tearDownDB() throws Exception {
+        fakeDB.close();
+    }
+}