[ONOS-2736] Fix bug of getting json from subnet.

Change-Id: I386f622fba74f0303a5ed9e6820ebc68a817021d
diff --git a/apps/vtnweb/src/main/java/org/onosproject/vtnweb/resources/VirtualPortWebResource.java b/apps/vtnweb/src/main/java/org/onosproject/vtnweb/resources/VirtualPortWebResource.java
index 64266a5..28f0c42 100644
--- a/apps/vtnweb/src/main/java/org/onosproject/vtnweb/resources/VirtualPortWebResource.java
+++ b/apps/vtnweb/src/main/java/org/onosproject/vtnweb/resources/VirtualPortWebResource.java
@@ -15,6 +15,7 @@
  */

 package org.onosproject.vtnweb.resources;

 

+import static com.google.common.base.Preconditions.checkArgument;

 import static com.google.common.base.Preconditions.checkNotNull;

 import static javax.ws.rs.core.Response.Status.INTERNAL_SERVER_ERROR;

 import static javax.ws.rs.core.Response.Status.OK;

@@ -209,6 +210,7 @@
                     .asText());

             TenantNetworkId networkId = TenantNetworkId.networkId(vPortnode

                     .get("network_id").asText());

+            checkArgument(vPortnode.get("admin_state_up").isBoolean(), "admin_state_up should be boolean");

             Boolean adminStateUp = vPortnode.get("admin_state_up").asBoolean();

             String state = vPortnode.get("status").asText();

             MacAddress macAddress = MacAddress.valueOf(vPortnode