SONA: Openstackswitching
 - Refactored the app to expose APIs to CordVtn App
 - Added clone method in OpenstackPort and OpenstackNetwork
 - Added NetworkConfig to select the working mode of the app
 - Added a few more APIs for getting network topology information
 - Integrated with the modified DhcpService app
Change-Id: I9e266aff10a00d80074d031276864fff195d2b3f
diff --git a/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
new file mode 100644
index 0000000..e504550
--- /dev/null
+++ b/apps/openstackswitching/app/src/main/java/org/onosproject/openstackswitching/web/OpenstackSubnetCodec.java
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2015 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.openstackswitching.web;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.collect.Lists;
+import org.onlab.packet.Ip4Address;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.openstackswitching.OpenstackSubnet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.List;
+
+/**
+ * Encodes and decodes the OpenstackSubnet.
+ */
+public class OpenstackSubnetCodec extends JsonCodec<OpenstackSubnet> {
+    private static Logger log = LoggerFactory
+            .getLogger(OpenstackSubnetCodec.class);
+
+    // JSON Field names
+    private static final String SUBNET = "subnet";
+    private static final String NAME = "name";
+    private static final String ENABLE_DHCP = "enable_dhcp";
+    private static final String NETWORK_ID = "network_id";
+    private static final String TENANT_ID = "tenant_id";
+    private static final String DNS_NAMESERVERS = "dns_nameservers";
+    private static final String GATEWAY_IP = "gateway_ip";
+    private static final String CIDR = "cidr";
+    private static final String ID = "id";
+
+    @Override
+    public OpenstackSubnet decode(ObjectNode json, CodecContext context) {
+        JsonNode subnetInfo = json.get(SUBNET);
+
+        String name = subnetInfo.path(NAME).asText();
+        boolean enableDhcp = subnetInfo.path(ENABLE_DHCP).asBoolean();
+        String networkId = subnetInfo.path(NETWORK_ID).asText();
+        String tenantId = subnetInfo.path(TENANT_ID).asText();
+        ArrayNode dnsNameservsers = (ArrayNode) subnetInfo.path(DNS_NAMESERVERS);
+        List<Ip4Address> dnsList = Lists.newArrayList();
+        if (dnsNameservsers != null && !dnsNameservsers.isMissingNode()) {
+            dnsNameservsers.forEach(dns -> dnsList.add(Ip4Address.valueOf(dns.asText())));
+        }
+        String gatewayIp = subnetInfo.path(GATEWAY_IP).asText();
+        String cidr = subnetInfo.path(CIDR).asText();
+        String id = subnetInfo.path(ID).asText();
+
+        OpenstackSubnet openstackSubnet = OpenstackSubnet.builder()
+                .setName(name)
+                .setEnableDhcp(enableDhcp)
+                .setNetworkId(networkId)
+                .setTenantId(tenantId)
+                .setDnsNameservers(dnsList)
+                .setGatewayIp(gatewayIp)
+                .setCidr(cidr)
+                .setId(id)
+                .build();
+        return openstackSubnet;
+    }
+}