Fix ONOS-5091

Change-Id: I11762eb799c1f93536f472807167cdba20a7c8e6
(cherry picked from commit 45f806ccedf844dfc8fe1722eca653f274b83f12)
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java
index 385f399..1fa9618 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/GroupCodec.java
@@ -82,7 +82,7 @@
                 .put(DEVICE_ID, group.deviceId().toString());
 
         if (group.appId() != null) {
-            result.put(APP_ID, group.appId().toString());
+            result.put(APP_ID, group.appId().name());
         }
 
         if (group.appCookie() != null) {
diff --git a/web/api/src/main/resources/definitions/Group.json b/web/api/src/main/resources/definitions/Group.json
index 53d226e..a96125a 100644
--- a/web/api/src/main/resources/definitions/Group.json
+++ b/web/api/src/main/resources/definitions/Group.json
@@ -62,7 +62,7 @@
     "appId": {
       "type": "string",
       "description": "application identifier",
-      "example": "1"
+      "example": "org.onosproject.rest"
     },
     "appCookie": {
       "type": "string",
diff --git a/web/api/src/main/resources/definitions/Groups.json b/web/api/src/main/resources/definitions/Groups.json
index 04273e0..50b6850 100644
--- a/web/api/src/main/resources/definitions/Groups.json
+++ b/web/api/src/main/resources/definitions/Groups.json
@@ -75,7 +75,7 @@
           "appId": {
             "type": "string",
             "description": "application identifier",
-            "example": "1"
+            "example": "org.onosproject.rest"
           },
           "appCookie": {
             "type": "string",
diff --git a/web/api/src/test/java/org/onosproject/rest/resources/GroupsResourceTest.java b/web/api/src/test/java/org/onosproject/rest/resources/GroupsResourceTest.java
index 63a7daa..67cf11b 100644
--- a/web/api/src/test/java/org/onosproject/rest/resources/GroupsResourceTest.java
+++ b/web/api/src/test/java/org/onosproject/rest/resources/GroupsResourceTest.java
@@ -280,9 +280,9 @@
 
             // check application id
             final String jsonAppId = jsonGroup.get("appId").asString();
-            final String appId = group.appId().toString();
+            final String appId = group.appId().name();
             if (!jsonAppId.equals(appId)) {
-                reason = "appId " + group.appId().toString();
+                reason = "appId " + group.appId().name();
                 return false;
             }