Automated Translation of Java Source Code to Eiffel

Reusability is an important software engineering concept actively advocated for the last forty years. While reusability has been addressed for systems implemented using the same programming language, it does not usually handle interoperability with different programming languages. This paper presents a solution for the reuse of Java code within Eiffel programs based on a source-to-source translation from Java to Eiffel. The paper focuses on the critical aspects of the translation and illustrates them by formal means. The translation is implemented in the freely available tool J2Eif; it provides Eiffel replacements for the components of the Java runtime environment, including Java Native Interface services and reflection mechanisms. Our experiments demonstrate the practical usability of the translation scheme and its implementation, and record the performance slow-down compared to custom-made Eiffel applications: automatic translations of java.util data structures, java.io services, and SWT applications can be re-used as Eiffel programs, with the same functionalities as their original Java implementations.