Wednesday, June 27, 2012

From FIQL expressions to typed JPA queries

Imagine you are working on the RESTful service implementation that relies on JPA2 but having a bit of a difficulty coming up with an interface that can neatly let users search the service data with queries allowing to express something more interesting than just "find all the data that have a given property equal to a given value".

Yes, FIQL is fantastic and its ability to express complex queries in a fairly simple and compact way is hard to beat.  CXF  offers an option to convert the captured FIQL expressions to other query languages and representations and now JPATypedQueryVisitor for converting FIQL queries to JPA2 TypedQuery or CriteriaQuery objects has been introduced. This can help users with creating typed JPA2 queries easily and getting the most of their JPA2-based services.

Major thanks to Jeff Wang for driving this enhancement with his contributions.

Next we will try to support hierarchical queries, for example, find all the chapters with a given content from books with a given set of properties or find all the books with the given properties that only have the chapters with a given content, etc. You can expect other useful converters, example for Casandra CQL and Lucene query languages, being added in time. Finally, the support for the alternative URI query languages is also on the map.

Watch this space :-)

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