Java Exception Handling Guidelines
Identify and apply robust Java exception handling practices to improve error clarity, security, debuggability, and system reliability.
What is covered in this Skill?
- Specific exception types instead of generic
Exception/RuntimeException
- try-with-resources for automatic resource cleanup
- Secure exception messages that avoid information leakage
- Exception chaining to preserve full error context
- Early input validation with
IllegalArgumentException/NullPointerException
InterruptedException handling with interrupted-status restoration@throws JavaDoc documentation, fail-fast principle- Structured logging with correlation IDs, avoiding log-and-throw duplication
- API boundary translation via centralized exception mappers
- Bounded retry with backoff for idempotent operations only
- Timeout enforcement with deadline propagation
Throwable#addSuppressed for secondary cleanup failures- Never catching
Throwable/Error
- Observability via error metrics
- Failure propagation in async
CompletionStage code
Scope: The reference is organized by examples (good/bad code patterns) for each core area. Apply recommendations based on applicable examples.
Constraints
Before applying any exception handling changes, ensure the project compiles. If compilation fails, stop immediately — do not proceed until resolved. After applying improvements, run full verification.
- MANDATORY: Run
./mvnw compile or mvn compile before applying any changes
- SAFETY: If compilation fails, stop immediately — do not proceed until the project is in a valid state
- VERIFY: Run
./mvnw clean verify or mvn clean verify after applying improvements
- BEFORE APPLYING: Read the reference for detailed good/bad examples, constraints, and safeguards for each exception handling pattern
When to use this skill
- Exception handling
- Use try-with-resources in Java code
- Create exception chaining in Java code
- Apply fail-fast validation in Java code
- Review Java exception taxonomy and propagation
Workflow
- Compile project before exception-handling changes
Run ./mvnw compile or mvn compile and stop immediately if compilation fails.
- Read exception-handling reference
Read references/126-java-exception-handling.md and identify applicable failure-handling and observability improvements.
- Apply exception-handling improvements
Refactor to specific exceptions, safe resource handling, error translation, and consistent logging patterns.
- Verify with full build
Run ./mvnw clean verify or mvn clean verify after applying improvements.
Reference
For detailed guidance, examples, and constraints, see references/126-java-exception-handling.md.