Restructuring the form of REST API deployment to provide
for security of app's REST APIs and for consistency of
exception mappers and JSON writer.

Change-Id: Id318372bf62f82ed974355c05e7fe64e0fbfc0c5
diff --git a/apps/dhcp/app/src/main/java/org/onosproject/dhcp/rest/DhcpWebResource.java b/apps/dhcp/app/src/main/java/org/onosproject/dhcp/rest/DhcpWebResource.java
index 6265fee..36c7a6c 100644
--- a/apps/dhcp/app/src/main/java/org/onosproject/dhcp/rest/DhcpWebResource.java
+++ b/apps/dhcp/app/src/main/java/org/onosproject/dhcp/rest/DhcpWebResource.java
@@ -44,7 +44,7 @@
 @Path("dhcp")
 public class DhcpWebResource extends AbstractWebResource {
 
-    final DhcpService service = get(DhcpService.class);
+    private final DhcpService service = get(DhcpService.class);
 
     /**
      * Get DHCP server configuration data.
@@ -56,12 +56,11 @@
     @GET
     @Path("config")
     public Response getConfigs() {
-        DhcpService service = get(DhcpService.class);
         ObjectNode node = mapper().createObjectNode()
                 .put("leaseTime", service.getLeaseTime())
                 .put("renewalTime", service.getRenewalTime())
                 .put("rebindingTime", service.getRebindingTime());
-        return ok(node.toString()).build();
+        return ok(node).build();
     }
 
     /**
@@ -76,13 +75,13 @@
     public Response listMappings() {
         ObjectNode root = mapper().createObjectNode();
 
-        final Map<HostId, IpAssignment> intents = service.listMapping();
+        Map<HostId, IpAssignment> intents = service.listMapping();
         ArrayNode arrayNode = root.putArray("mappings");
         intents.entrySet().forEach(i -> arrayNode.add(mapper().createObjectNode()
                                                               .put("host", i.getKey().toString())
                                                               .put("ip", i.getValue().ipAddress().toString())));
 
-        return ok(root.toString()).build();
+        return ok(root).build();
     }
 
 
@@ -96,12 +95,11 @@
     @GET
     @Path("available")
     public Response listAvailableIPs() {
-        final Iterable<Ip4Address> availableIPList = service.getAvailableIPs();
-
-        final ObjectNode root = mapper().createObjectNode();
+        Iterable<Ip4Address> availableIPList = service.getAvailableIPs();
+        ObjectNode root = mapper().createObjectNode();
         ArrayNode arrayNode = root.putArray("availableIP");
         availableIPList.forEach(i -> arrayNode.add(i.toString()));
-        return ok(root.toString()).build();
+        return ok(root).build();
     }
 
     /**
@@ -139,7 +137,7 @@
         } catch (IOException e) {
             throw new IllegalArgumentException(e.getMessage());
         }
-        return ok(root.toString()).build();
+        return ok(root).build();
     }
 
     /**
@@ -152,7 +150,6 @@
     @DELETE
     @Path("mappings/{macID}")
     public Response deleteMapping(@PathParam("macID") String macID) {
-
         ObjectNode root = mapper().createObjectNode();
 
         if (!service.removeStaticMapping(MacAddress.valueOf(macID))) {
@@ -164,6 +161,6 @@
                                                               .put("host", i.getKey().toString())
                                                               .put("ip", i.getValue().ipAddress().toString())));
 
-        return ok(root.toString()).build();
+        return ok(root).build();
     }
 }