Downgrading Java 5.0 Projects : An approach based on source-code transformations

Abstract: The introduction of Java 5.0 came along with an extension of the language syntax. Several new language features as generic types and enumeration types were added to the language specification. These features cause downward-incompatibilities, code written in Java 5.0 will not work on older versions of the Java runtime environment. For some active projects, however, it is not possible to upgrade to higher Java versions, since some code might not be supported on Java 5.0. If one still wants to use components written in Java 5.0, these must be downgraded. Up to now this has been accomplished mostly by transforming the byte code of these programs. In this thesis, we present a set of transformations which transform Java 5.0 source code to Java 1.4 compatible code. We successfully apply these transformations to two larger projects and compare our approach to the up to now common byte-code based tools.