Type qualifiers for Java

Abstract

We describe Jqual, a practical framework for type qualifier inference in Java. Jqual is implemented as an Eclipse plug-in that allows researchers to quickly develop and test modifications to the Java type system based on the flexible, lightweight and familiar mechanism of type qualifiers. We demonstrate one such analysis which supports specification and checking of reference immutability for Java types modeled on the Javari language[2]. Finally, we describe the results of applying this analysis to a moderate-sized sample program.