Java 8 introduces two functional features: lambda expressions and functional operations like filter, map, or reduce that apply a lambda expression over the elements of a Collection. Refactoring existing code to use these new features enables explicit but unobtrusive parallelism and makes the code more succinct. However, refactoring is tedious (it requires changing many lines of code) and error-prone (the programmer must reason about the control-flow, data-flow, and side-effects). Fortunately, these refactorings can be automated.
We present LAMBDAFICATOR, a tool which automates two refactorings. The first refactoring converts anonymous inner classes to lambda expressions. The second refactoring converts for loops that iterate over Collections to functional operations that use lambda expressions. In 9 open-source projects we have applied these two refactorings 1263 and 1595 times, respectively. The results show that LambdaFicator is effective.
A video highlighting the main features can be found here.
LambdaFicator is integrated in the official release of the NetBeans IDE. More info about the tool and how to use it are on refactoring.info.