java - Why Sonar says Constructor Calls Overridable Method when there is no overridable method called? -

i getting following code issue in sonar . class implements basedatabase interface method not called constructor.

public class derbydatabasehelper implements basedatabase {      private static boolean isinitializationdone;     private static connection connection;     private static final logger logger = logger             .getlogger(derbydatabasehelper.class);      /**      * @param connection      *            connection set      */     private static void setconnection(connection connection) {         derbydatabasehelper.connection = connection;     }      public derbydatabasehelper() {         deletederbyfolder(new file("newdb"));         if (!isinitializationdone) {             initializedb();             setinitializationdone(true);         }     }      /**      * method initializes derby schema.      */     private void initializedb() {         try {             // scriptrunner of apache ibatis execute sql file             // creating database schema in derbydb .             new scriptrunner(getconnection())                     .runscript(new inputstreamreader(new fileinputstream(                             configreader.getvalue("schemafilepath")), charset                             .defaultcharset()));         } catch (exception e) {             logger.error(                     "exception occurred during initialization of db.  exception details :: ",                     e);         } {             closeconnection();         }      }      /**      * method used derby database connection object      */     @override     public connection getconnection() {         if (connection == null) {             try {                 loadderbyclass();                 // create jdbc connection                 setconnection(drivermanager.getconnection(configreader                         .getvalue("initialurl")                         + configreader.getvalue("dbname")                         + configreader.getvalue("createdb")));              } catch (sqlexception e) {                 logger.error(                         "exception occurred during creating connection.  exception details :: ",                         e);             }         }         return connection;     }      /**      * method used close acquired derby database connection      * object.      */     @override     public void closeconnection() {         if (connection != null) {             try {                 connection.close();             } catch (exception e) {                 logger.error(                         "exception occurred during closing connection.  exception details :: ",                         e);             }         }     } 

and interface

public interface basedatabase {      connection getconnection();      void closeconnection();  } 

as can see there no overriden method called constructor,is sonar not able interpret issue.