ATLAS-4667: Cannot create subclassification using subTypes field

intg/src/main/java/org/apache/atlas/AtlasErrorCode.java

@@ -184,6 +184,7 @@ public enum AtlasErrorCode {
     BLANK_VALUE_ATTRIBUTE(400, "ATLAS-400-00-105", "Value Attribute can't be empty!"),
     INVALID_RELATIONSHIP_LABEL(400, "ATLAS-400-00-106", "Invalid relationship label {0}. The referenced entity type {1} could not be resolved from the type registry."),
     NON_INDEXABLE_BM_DELETE_NOT_ALLOWED(400, "ATLAS-400-00-107", "Deletion not allowed for non-indexable Business Metadata ''{0}'' without force=true. Non-indexable attributes cannot be validated efficiently for references; use force=true to skip validation and delete (warning: orphaned references may remain)."),
+    CLASSIFICATIONDEF_SUBTYPES_NOT_ALLOWED(400, "ATLAS-400-00-107", "ClassificationDef {0}: subTypes is a derived field and cannot be specified during create/update. To establish a parent-child relationship, set superTypes on the child classification instead."),
 
     UNAUTHORIZED_ACCESS(403, "ATLAS-403-00-001", "{0} is not authorized to perform {1}"),
 

repository/src/main/java/org/apache/atlas/repository/store/graph/AtlasTypeDefGraphStore.java

@@ -423,6 +423,7 @@ public AtlasTypesDef createTypesDef(AtlasTypesDef typesDef) throws AtlasBaseExce
         }
 
         AtlasTransientTypeRegistry ttr = lockTypeRegistryAndReleasePostCommit();
+        validateClassificationDefsHaveNoSubTypes(typesDef);
         tryTypeCreation(typesDef, ttr);
 
         AtlasTypesDef ret = addToGraphStore(typesDef, ttr);
@@ -460,7 +461,7 @@ public AtlasTypesDef updateTypesDef(AtlasTypesDef typesDef) throws AtlasBaseExce
         }
 
         AtlasTransientTypeRegistry ttr = lockTypeRegistryAndReleasePostCommit();
-
+        validateClassificationDefsHaveNoSubTypes(typesDef);
         // Translate any NOT FOUND errors to BAD REQUEST
         try {
             ttr.updateTypes(typesDef);
@@ -493,6 +494,17 @@ public AtlasTypesDef updateTypesDef(AtlasTypesDef typesDef) throws AtlasBaseExce
         return ret;
     }
 
+    private void validateClassificationDefsHaveNoSubTypes(AtlasTypesDef typesDef) throws AtlasBaseException {
+        if (CollectionUtils.isNotEmpty(typesDef.getClassificationDefs())) {
+            for (AtlasClassificationDef classificationDef : typesDef.getClassificationDefs()) {
+                if (CollectionUtils.isNotEmpty(classificationDef.getSubTypes())) {
+                    LOG.info("ClassificationDef {}: subTypes is a derived field and cannot be specified during create/update. To establish a parent-child relationship, set superTypes on the child instead.", classificationDef.getName());
+                    throw new AtlasBaseException(AtlasErrorCode.CLASSIFICATIONDEF_SUBTYPES_NOT_ALLOWED, classificationDef.getName());
+                }
+            }
+        }
+    }
+
     @Override
     @GraphTransaction
     public AtlasTypesDef createUpdateTypesDef(AtlasTypesDef typesDef) throws AtlasBaseException {