uber/NullAway
NullAway
NullAway is a Java static analysis tool and build-time detector designed to identify null pointer risks. It functions as a nullability checker that uses annotations to verify that references are not null before they are dereferenced, preventing runtime crashes.
The analyzer implements the JSpecify standard to ensure consistent nullability annotations across different Java libraries. It distinguishes itself through the use of a service provider interface to model the nullability behavior of third-party libraries that lack source annotations and by providing specialized support for Lombok-generated code.
The tool covers a broad range of safety enforcement capabilities, including Java API contract validation for method overrides and the detection of empty optional value retrieval. Its analysis surface extends to package-level nullability marking and the ability to exclude generated source code from analysis.
Features
- Null Safety Enforcement - Provides compile-time analysis to detect null pointer risks and enforce null safety across Java codebases.
- Nullability Standard Implementations - Implements the JSpecify standard to ensure consistent nullability annotations across different Java libraries.
- Nullability Checkers - Functions as a nullability checker that uses annotations to verify references are not null before dereferencing.
- Java Static Analysis Tools - Serves as a full static analysis tool for Java source code to enforce null safety rules.
- Build-Time Null Check Verification - Provides a compiler-integrated check that identifies null pointer risks in Java projects during the build phase.
- Nullability Annotations - Provides a standardized set of nullability annotations to ensure consistent interpretation across static analysis tools.
- Syntax Tree Analysis - Analyzes the program's abstract syntax tree to track nullability states across variables and method calls.
- Null Pointer Exception Detection - Performs local type-based checks using annotations to ensure dereferenced pointers are not null.
- Static Code Analysis - Integrates automated null checks into the build process to detect potential crashes before deployment.
- Method Contract Verification - Ensures that overriding methods maintain consistent nullability contracts with their super-type methods.
- Static Contract Analysis - Performs compile-time verification of behavioral contracts to reason about method nullability.
- Third Party Library Typing - Provides a way to define nullability behavior for external libraries that lack native annotations.
- Lombok AST Integration - Recognizes common Lombok annotations to maintain compatibility with in-memory modifications of the abstract syntax tree.
- Nullability Contract Linting - Verifies that method overrides and library calls maintain consistent nullability rules to prevent runtime crashes.
- Behavioral Contract Validation - Evaluates behavioral contract annotations to reason about method side effects and return values.
- Compiler-Integrated Analysis - Integrates directly into the Java compilation process to perform analysis with minimal impact on build speed.
- Pluggable Service Provider Interfaces - Uses a pluggable service provider interface to model nullability for third-party libraries lacking source annotations.
- Optional Value Validations - Detects calls to retrieve values from empty optionals unless a presence check is performed first.
- Package-Level Nullability Marking - Applies nullability rules to entire packages to avoid requiring annotations on every individual class.
- Standardized Nullability Analyzers - Provides an analysis engine that supports the JSpecify standard for consistent nullability across Java libraries.
- Code Analysis - Build-time tool to eliminate NullPointerExceptions.
- Static Analysis Tools - Type-based null-pointer checker for Java.
