language-java

What problem does it solve?

It helps you produce idiomatic, maintainable Java by applying modern language features and best practices for data modeling, null handling, concurrency, errors, collections, and testing.

Core Features & Use Cases

• Records & sealed types: Use record for immutable data carriers and sealed hierarchies with exhaustive switch for clearer domain modeling.
• Null & optional discipline: Return Optional<T> for legitimate absence, avoid using it as fields/parameters, and use nullability annotations for static analysis.
• Modern concurrency & error handling: Prefer virtual threads (JDK 21+) with structured concurrency patterns, and translate exceptions at boundaries for clean domain errors.
• Streams & testing: Use streams for transformation pipelines, and write tests with JUnit 5 plus AssertJ and Mockito at appropriate boundaries.

Quick Start

Ask for a Java snippet that models your domain with records and sealed interfaces, uses Optional correctly, and includes a JUnit 5 test with AssertJ assertions based on the behavior you describe.