A fast, practical, static nullness checker for Java

NullAway takes in code following an intuitive annotation discipline, where values that might be null at runtime, must be annotated with @Nullable. It performs type-based local analysis to ensure that any pointer that gets dereferenced in annotated code cannot be null, and thus prevent NullPointerExceptions (NPEs). In our measurements, the build-time overhead of running NullAway is usually less than 20% of javac, which allows us to use it to analize all of Uber Android Java code on every local compilation.

with Manu Sridharan, Subarno Banerjee, and others at Uber

A static analysis tool for preventing UI access off the main thread in stream-based (RxJava/RxAndroid) Android applications.

The RxThreadEffectChecker is built on the Checker Framework, and particularly it works in tandem with their guieffect checker. It extends these checkers with awaraness of the ReactiveX stream-based threading model. We have deployed RxThreadEffectChecker at Uber and are working on a faster iteration of this tool, using the same type system.

with Benno Stein, Manu Sridharan, and others at Uber