Type safety and expressiveness of many existing Java libraries and their client applications would improve, if the libraries were upgraded to define generic classes. Efficient and accurate tools exist to assist client applications to use generic libraries, but so far the libraries themselves must be parameterized manually, which is a tedious, time-consuming, and error-prone task. We present a typeconstraint-based algorithm for converting non-generic libraries to add type parameters. The algorithm handles the full Java language and preserves backward compatibility, thus making it safe for existing clients. Among other features, it is capable of inferring wildcard types and introducing type parameters for mutually-dependent classes. We have implemented the algorithm as a fully automatic refactoring in Eclipse. We evaluated our work in two ways. First, our tool parameterized code that was lacking type parameters. We contacted the developers of several of these applications, and in all ca...
Adam Kiezun, Michael D. Ernst, Frank Tip, Robert M