This module should provide in particular:

• The most commonly used annotations from Search 5, as well as integration code to detect and apply these annotations to the ORM mapping.
• An implementation of the main runtime APIs:
• The Search class to retrieve the FullTextEM/FullTextSession
• The most commonly used methods of FullTextEM/FullTextSession (createFullTextQuery() and index() in particular)
• The QueryBuilder
• The most commonly used methods of FullTextQuery

Parts of the APIs may be dropped if they are not very often used and/or close to impossible to support in Search 6.

The compatibility layer is only expected to work when mapping ORM entities to Lucene indexes. Elasticsearch integration and JMS/JGroups backends, in particular, are out of scope.

We might have to rename or relocate some Search 6 classes to avoid conflicts with the classes in the compatibility layer.

Note that, in order to implement the QueryBuilder in the compatibility layer, we have two solutions:

• Just copy/pasting the old DSL code from Search 5 and re-implement everything it needs on top of Search 6. In particular, implement the old metamodel. Might be time-consuming.
• OR Reimplement the old DSL by redirecting calls the new DSL. Might change behavior slightly.

We might want to create subtasks to implement this bits by bits.