Formalizing the Well-formedness Rules of EJB3QL in UML + OCL

Abstract. This paper reports the application of language metamodeling techniques to EJB3QL, the object-oriented query language for Java Persistence recently standardized in JSR-220. Five years from now, today’s EJB3 applications will be legacy. We see our metamodel as an enabler for increasing the efficiency of reverse engineering activities. It has already proven useful in uncovering spots where the EJB3QL spec is vague. The case study reported in this paper involved (a) expressing the abstract syntax and well-formedness rules of EJB3QL in UML and OCL respectively; (b) deriving from that metamodel software artifacts required for several language-processing tasks, targeting two modeling platforms (Eclipse EMF and Octopus); and (c) comparing the generated artifacts with their counterparts in the reference implementation of EJB3 (which was not developed following a language-metamodeling approach). The metamodel of EJB3QL constitutes the basis for applying model-checkers to aid in assuring conformance of tools claiming to support the specification.