143-java-functional-exception-handling

Identify and apply functional exception handling best practices in Java to improve error clarity, maintainability, and performance by eliminating exception overuse in favour of monadic error types.

Prerequisites: Run ./mvnw validate or mvn validate before applying any changes. If validation fails, stop immediately — do not proceed until the project is in a valid state. Also confirm the VAVR dependency (io.vavr:vavr) and SLF4J are present when introducing Either types.

Core areas: Optional for nullable values over throwing NullPointerException or NotFoundException, VAVR Either for predictable business-logic failures, CompletableFuture for async error handling, sealed classes and records for rich error type hierarchies with exhaustive pattern matching, enum-based error types for simple failure cases, functional composition with flatMap/map/peek/peekLeft for chaining operations th...

當您需要在 Java 中應用功能異常處理最佳實踐時使用 - 包括用Optional和VAVR Either 類型替換異常過度使用、使用密封類別和枚舉設計錯誤類型層次結構、實現單子錯誤組合管道、建立功能控制流模式以及僅為真正異常的系統級故障保留異常。 java 技能專案的一部分 來源：jabrena/cursor-rules-java。