Instead of using Hibernate Search 5 APIs, get a org.hibernate.search.mapper.orm.session.SearchSession
using org.hibernate.search.mapper.orm.Search#session(org.hibernate.Session),
create a mass indexer with org.hibernate.search.mapper.orm.session.SearchSession#massIndexer(Class[]),
and implement the interface org.hibernate.search.mapper.orm.massindexing.MassIndexingMonitor
in your monitor.
org.hibernate.search.mapper.orm.session.SearchSessionusingorg.hibernate.search.mapper.orm.Search#session(org.hibernate.Session), create a mass indexer withorg.hibernate.search.mapper.orm.session.SearchSession#massIndexer(Class[]), and implement the interfaceorg.hibernate.search.mapper.orm.massindexing.MassIndexingMonitorin your monitor.