Typestate protocol specification in JML

The Java Modeling Language (JML) is a language for specifying the behavior of Java source code. However, it can describe the protocols of Java classes and interfaces only implicitly. Typestate protocol specification is a more direct, lightweight and abstract way of documenting usage protocols for object-oriented programs. In this paper, we propose a technique for incorporating the typestate concept into JML for specifying protocols of Java classes and interfaces, based on our previous research on typestate protocol specifications [4]. This paper presents a set of formal translation rules for encoding typestate protocol specifications into pre/post-condition specifications. It shows how typestate protocol specifications can be mixed with pre/post-condition specifications and how violations of code contracts in inheritance can be handled. Finally, our proposed technique is demonstrated within the Java/JML environment to show its effectiveness.