ATLAS-3202: Hive hook: getStorageDescEntity() throws NPE if bucketCols is null

addons/hive-bridge/src/main/java/org/apache/atlas/hive/hook/events/BaseHiveEvent.java

@@ -475,7 +475,7 @@ public abstract class BaseHiveEvent {
             ret.setAttribute(ATTRIBUTE_NUM_BUCKETS, sd.getNumBuckets());
             ret.setAttribute(ATTRIBUTE_STORED_AS_SUB_DIRECTORIES, sd.isStoredAsSubDirectories());
 
-            if (sd.getBucketCols().size() > 0) {
+            if (sd.getBucketCols() != null && sd.getBucketCols().size() > 0) {
                 ret.setAttribute(ATTRIBUTE_BUCKET_COLS, sd.getBucketCols());
             }
 
@@ -514,8 +514,9 @@ public abstract class BaseHiveEvent {
     protected List<AtlasEntity> getColumnEntities(AtlasObjectId tableId, Table table, List<FieldSchema> fieldSchemas) {
         List<AtlasEntity> ret            = new ArrayList<>();
         boolean           isKnownTable   = tableId.getGuid() == null;
-
         int               columnPosition = 0;
+
+        if (CollectionUtils.isNotEmpty(fieldSchemas)) {
             for (FieldSchema fieldSchema : fieldSchemas) {
                 String      colQualifiedName = getQualifiedName(table, fieldSchema);
                 AtlasEntity column           = context.getEntity(colQualifiedName);
@@ -543,6 +544,7 @@ public abstract class BaseHiveEvent {
 
                 ret.add(column);
             }
+        }
 
         return ret;
     }