Apply more functional style

Change-Id: Ib2194054dcddbc975f426c5a17a89031e3b1166d
diff --git a/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbBridgeConfig.java b/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbBridgeConfig.java
index 90a5a88..401a64f 100644
--- a/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbBridgeConfig.java
+++ b/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbBridgeConfig.java
@@ -16,8 +16,8 @@
 package org.onosproject.driver.ovsdb;
 
 import java.util.Collection;
-import java.util.HashSet;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.onlab.packet.IpAddress;
 import org.onosproject.net.DeviceId;
@@ -36,8 +36,6 @@
 import org.onosproject.ovsdb.controller.OvsdbNodeId;
 import org.onosproject.ovsdb.controller.OvsdbPort;
 
-import com.google.common.collect.Sets;
-
 /**
  * The implementation of BridageConfig.
  */
@@ -63,18 +61,16 @@
         DriverHandler handler = handler();
         DeviceId deviceId = handler.data().deviceId();
         OvsdbClientService clientService = getOvsdbClientService(handler);
-        Set<OvsdbBridge> ovsdbSet = clientService.getBridges();
-        Collection<BridgeDescription> bridges = Sets.newHashSet();
-        ovsdbSet.forEach(o -> {
-            BridgeName bridgeName = BridgeName
-                    .bridgeName(o.bridgeName().value());
-            DeviceId ownDeviceId = DeviceId.deviceId("of:" + o.datapathId().value());
-            BridgeDescription description = new DefaultBridgeDescription(bridgeName,
-                                                                         deviceId,
-                                                                         ownDeviceId);
-            bridges.add(description);
-        });
-        return bridges;
+        Set<OvsdbBridge> bridges = clientService.getBridges();
+
+        return bridges.stream()
+                .map(x -> new DefaultBridgeDescription(
+                                BridgeName.bridgeName(x.bridgeName().value()),
+                                deviceId,
+                                DeviceId.deviceId("of:" + x.datapathId().value())
+                        )
+                )
+                .collect(Collectors.toSet());
     }
 
     @Override
@@ -105,14 +101,15 @@
     public Collection<PortDescription> getPorts() {
         DriverHandler handler = handler();
         OvsdbClientService clientService = getOvsdbClientService(handler);
-        Set<OvsdbPort> ovsdbSet = clientService.getPorts();
-        Collection<PortDescription> ports = Sets.newHashSet();
-        ovsdbSet.forEach(o -> {
-            PortNumber port = PortNumber.portNumber(o.portNumber().value());
-            PortDescription description = new DefaultPortDescription(port, true);
-            ports.add(description);
-        });
-        return ports;
+        Set<OvsdbPort> ports = clientService.getPorts();
+
+        return ports.stream()
+                .map(x -> new DefaultPortDescription(
+                                PortNumber.portNumber(x.portNumber().value()),
+                                true
+                        )
+                )
+                .collect(Collectors.toSet());
     }
 
     // OvsdbNodeId(IP:port) is used in the adaptor while DeviceId(ovsdb:IP:port)
@@ -137,15 +134,16 @@
 
     @Override
     public Set<PortNumber> getPortNumbers() {
-        Set<PortNumber> ports = new HashSet<>();
         DriverHandler handler = handler();
         OvsdbClientService clientService = getOvsdbClientService(handler);
-        Set<OvsdbPort> ovsdbSet = clientService.getPorts();
-        ovsdbSet.forEach(o -> {
-            PortNumber port = PortNumber.portNumber(o.portNumber().value(),
-                                                    o.portName().value());
-            ports.add(port);
-        });
-        return ports;
+        Set<OvsdbPort> ports = clientService.getPorts();
+
+        return ports.stream()
+                .map(x -> PortNumber.portNumber(
+                                x.portNumber().value(),
+                                x.portName().value()
+                        )
+                )
+                .collect(Collectors.toSet());
     }
 }
diff --git a/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbTunnelConfig.java b/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbTunnelConfig.java
index 1c99c16..d32fb6b 100644
--- a/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbTunnelConfig.java
+++ b/drivers/src/main/java/org/onosproject/driver/ovsdb/OvsdbTunnelConfig.java
@@ -18,6 +18,7 @@
 import java.util.Collection;
 
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.onlab.packet.IpAddress;
 import org.onosproject.net.DeviceId;
@@ -25,7 +26,6 @@
 import org.onosproject.net.behaviour.IpTunnelEndPoint;
 import org.onosproject.net.behaviour.TunnelConfig;
 import org.onosproject.net.behaviour.TunnelDescription;
-import org.onosproject.net.behaviour.TunnelEndPoint;
 import org.onosproject.net.behaviour.TunnelName;
 import org.onosproject.net.driver.AbstractHandlerBehaviour;
 import org.onosproject.net.driver.DriverHandler;
@@ -34,8 +34,6 @@
 import org.onosproject.ovsdb.controller.OvsdbNodeId;
 import org.onosproject.ovsdb.controller.OvsdbTunnel;
 
-import com.google.common.collect.Sets;
-
 /**
  * OVSDB-based implementation of tunnel config behaviour.
  */
@@ -90,20 +88,18 @@
     public Collection<TunnelDescription> getTunnels() {
         DriverHandler handler = handler();
         OvsdbClientService ovsdbNode = getOvsdbNode(handler);
-        Set<OvsdbTunnel> ovsdbSet = ovsdbNode.getTunnels();
-        Collection<TunnelDescription> tunnels = Sets.newHashSet();
-        ovsdbSet.forEach(o -> {
-            TunnelEndPoint ipSrc = IpTunnelEndPoint.ipTunnelPoint(o.localIp());
-            TunnelEndPoint ipDst = IpTunnelEndPoint.ipTunnelPoint(o.remoteIp());
-            TunnelName name = TunnelName.tunnelName(o.tunnelName().toString());
-            TunnelDescription des = new DefaultTunnelDescription(
-                                                                 ipSrc,
-                                                                 ipDst,
-                                                                 TunnelDescription.Type.VXLAN,
-                                                                 name);
-            tunnels.add(des);
-        });
-        return tunnels;
+        Set<OvsdbTunnel> tunnels = ovsdbNode.getTunnels();
+
+        return tunnels.stream()
+                .map(x ->
+                        new DefaultTunnelDescription(
+                                IpTunnelEndPoint.ipTunnelPoint(x.localIp()),
+                                IpTunnelEndPoint.ipTunnelPoint(x.remoteIp()),
+                                TunnelDescription.Type.VXLAN,
+                                TunnelName.tunnelName(x.tunnelName().toString())
+                        )
+                )
+                .collect(Collectors.toSet());
     }
 
     // OvsdbNodeId(IP:port) is used in the adaptor while DeviceId(ovsdb:IP:port)