description added for exception: JavaDoc warning fixed

Change-Id: Ifd58774b11e3776c4c8c3211e0a9035bd5be7c6d

@@ -187,7 +187,7 @@ public class FloatingIpWebResource extends AbstractWebResource {
      *
      * @param floatingIpNodes the floatingIp json node
      * @return floatingIps a collection of floatingIp
-     * @throws Exception
+     * @throws Exception when any argument is illegal
      */
     public Collection<FloatingIp> changeJsonToSub(JsonNode floatingIpNodes)
             throws Exception {

@@ -293,7 +293,7 @@ public class RouterWebResource extends AbstractWebResource {
      *
      * @param routerNode the router json node
      * @return routers a collection of router
-     * @throws Exception
+     * @throws Exception when any argument is illegal
      */
     public Collection<Router> changeJsonToSub(JsonNode routerNode)
             throws Exception {