Identify and apply modern Java (Java 8+) refactoring opportunities to improve readability, maintainability, and performance.
Prerequisites: Run ./mvnw compile or mvn compile before applying any changes. If compilation fails, stop immediately — do not proceed until the project compiles successfully.
Core areas: Lambda expressions and method references (over anonymous classes), Stream API for declarative collection processing, Optional for null-safe APIs, java.time API (replacing Date/Calendar), default interface methods, var type inference, unmodifiable collection factory methods (List.of(), Set.of(), Map.of()), CompletableFuture for composable async programming, text blocks for multi-line strings, Java 25 Fl...
Use when you need to refactor Java code to adopt modern Java features (Java 8+) — including migrating anonymous classes to lambdas, replacing Iterator loops with Stream API, adopting Optional for null safety, switching from legacy Date/Calendar to java.time, using collection factory methods, migrating to CompletableFuture for async operations, applying text blocks, var inference, or leveraging Java 25 features like flexible constructor bodies and module import declarations. Part of the skills-for-java project Source: jabrena/cursor-rules-java.