add a delete vBNG feature

Change-Id: I21ce31d645be31320d06c36795e6b044f11924ab
diff --git a/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngResource.java b/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngResource.java
index 9436981..2b0cd98 100644
--- a/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngResource.java
+++ b/apps/virtualbng/src/main/java/org/onosproject/virtualbng/VbngResource.java
@@ -17,6 +17,7 @@
 
 import static org.slf4j.LoggerFactory.getLogger;
 
+import javax.ws.rs.DELETE;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.PathParam;
@@ -35,13 +36,13 @@
 
     @POST
     @Path("{privateip}")
-    public String privateIpNotification(@PathParam("privateip")
+    public String privateIpAddNotification(@PathParam("privateip")
             String privateIp) {
         if (privateIp == null) {
-            log.info("Private IP address is null");
+            log.info("Private IP address to add is null");
             return "0";
         }
-        log.info("Received a private IP address : {}", privateIp);
+        log.info("Received a private IP address : {} to add", privateIp);
         IpAddress privateIpAddress = IpAddress.valueOf(privateIp);
 
         VbngService vbngService = get(VbngService.class);
@@ -56,4 +57,28 @@
             return "0";
         }
     }
+
+    @DELETE
+    @Path("{privateip}")
+    public String privateIpDeleteNotification(@PathParam("privateip")
+            String privateIp) {
+        if (privateIp == null) {
+            log.info("Private IP address to delete is null");
+            return "0";
+        }
+        log.info("Received a private IP address : {} to delete", privateIp);
+        IpAddress privateIpAddress = IpAddress.valueOf(privateIp);
+
+        VbngService vbngService = get(VbngService.class);
+
+        IpAddress assignedPublicIpAddress = null;
+        // Delete a virtual BNG
+        assignedPublicIpAddress = vbngService.deleteVbng(privateIpAddress);
+
+        if (assignedPublicIpAddress != null) {
+            return assignedPublicIpAddress.toString();
+        } else {
+            return "0";
+        }
+    }
 }
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