This paper presents a solution to the lack of tool-support for the JML models verification. We propose an approach for expressing JML specifications within the B abstract machines notation. The B machines generated from the JML can then be checked to ensure their correctness. Thus, we deduce the correctness of the original JML specification, ensured by rewriting rules which give the semantical equivalence of the two models. More generally, this translation can be applied to object-oriented specification languages using before-after predicates.