ATLAS-2897: Better handling of empty zip files.

repository/src/main/java/org/apache/atlas/repository/impexp/AtlasServerService.java

@@ -65,7 +65,6 @@ public class AtlasServerService {
         try {
             return dataAccess.load(server);
         } catch (AtlasBaseException e) {
-            LOG.error("dataAccess", e);
             throw e;
         }
     }

repository/src/main/java/org/apache/atlas/repository/impexp/ZipSource.java

@@ -72,10 +72,14 @@ public class ZipSource implements EntityImportStream {
     }
 
     private boolean isZipFileEmpty() {
-        return MapUtils.isEmpty(guidEntityJsonMap) ||
-                (guidEntityJsonMap.containsKey(ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME.toString()) &&
-                        (guidEntityJsonMap.get(ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME.toString()) == null)
-                );
+        if (MapUtils.isEmpty(guidEntityJsonMap))  {
+            return true;
+        }
+
+        String key = ZipExportFileNames.ATLAS_EXPORT_ORDER_NAME.toString();
+        return (guidEntityJsonMap.containsKey(key) &&
+                         StringUtils.isNotEmpty(guidEntityJsonMap.get(key)) &&
+                                 guidEntityJsonMap.get(key).equals("[]"));
     }
 
     public ImportTransforms getImportTransform() { return this.importTransform; }