Mark netconf related factory as functional interface

- deprecate/remove redundant factory implementations

Change-Id: I29ba9f3397c37c02b37d07dff16a4203186c5fcd
diff --git a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/DefaultNetconfDevice.java b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/DefaultNetconfDevice.java
index f700768..c952027 100644
--- a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/DefaultNetconfDevice.java
+++ b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/DefaultNetconfDevice.java
@@ -49,7 +49,7 @@
     public DefaultNetconfDevice(NetconfDeviceInfo deviceInfo)
             throws NetconfException {
         netconfDeviceInfo = deviceInfo;
-        sessionFactory = new NetconfSessionMinaImpl.MinaSshNetconfSessionFactory();
+        sessionFactory = (ncDevInfo) -> new NetconfSessionMinaImpl(ncDevInfo);
         try {
             netconfSession = sessionFactory.createNetconfSession(deviceInfo);
         } catch (NetconfException e) {
diff --git a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfControllerImpl.java b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfControllerImpl.java
index ab0189d..e0959cd 100644
--- a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfControllerImpl.java
+++ b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfControllerImpl.java
@@ -118,7 +118,7 @@
     private final NetconfDeviceOutputEventListener downListener = new DeviceDownEventListener();
 
     protected Set<NetconfDeviceListener> netconfDeviceListeners = new CopyOnWriteArraySet<>();
-    protected NetconfDeviceFactory deviceFactory = new DefaultNetconfDeviceFactory();
+    protected NetconfDeviceFactory deviceFactory = (deviceInfo) -> new DefaultNetconfDevice(deviceInfo);
 
     protected final ExecutorService executor =
             Executors.newCachedThreadPool(groupedThreads("onos/netconfdevicecontroller",
@@ -343,14 +343,17 @@
     }
 
 
-    //Device factory for the specific NetconfDeviceImpl
+    /**
+     * Device factory for the specific NetconfDeviceImpl.
+     *
+     * @deprecated in 1.14.0
+     */
+    @Deprecated
     private class DefaultNetconfDeviceFactory implements NetconfDeviceFactory {
 
         @Override
         public NetconfDevice createNetconfDevice(NetconfDeviceInfo netconfDeviceInfo)
                 throws NetconfException {
-            log.info("Creating NETCONF session to {} with {}",
-                    netconfDeviceInfo.getDeviceId(), NetconfSshClientLib.APACHE_MINA);
             return new DefaultNetconfDevice(netconfDeviceInfo);
         }
     }
diff --git a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java
index 31ec0ac..846ec26 100644
--- a/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java
+++ b/protocols/netconf/ctl/src/main/java/org/onosproject/netconf/ctl/impl/NetconfSessionMinaImpl.java
@@ -199,6 +199,9 @@
     }
 
     private void startClient() throws IOException {
+        log.info("Creating NETCONF session to {}",
+                 deviceInfo.getDeviceId());
+
         client = SshClient.setUpDefaultClient();
         client.getProperties().putIfAbsent(FactoryManager.IDLE_TIMEOUT,
                 TimeUnit.SECONDS.toMillis(idleTimeout));
@@ -1019,6 +1022,10 @@
         }
     }
 
+    /**
+     * @deprecated in 1.14.0
+     */
+    @Deprecated
     public static class MinaSshNetconfSessionFactory implements NetconfSessionFactory {
 
         @Override