Skill: java-exception-robustness

Activation Contract

Use this skill when reviewing or designing Java exception handling, resource cleanup, checked/unchecked exception choices, failure boundaries, retry/fallback policy, and robust service behavior.

Do not use this skill for logging-only changes, security-only auditing, non-Java error models, or framework-specific exception mapping with no Java design question.

Responsibility

This skill teaches Java failure-handling design. It does not call other skills, hide failures by default, or invent business recovery policies.

Required Context

• Operation being protected.
• Who can recover from failures.
• Resource ownership and cleanup needs.
• Whether this is library, application, batch, or long-running service code.
• Sensitive-data constraints in messages/logs.

Context Budget

• Keep this SKILL.md focused on error boundaries.
• Use references/java-exception-guidance.md for detailed choices.

Hard Rules

• Do not swallow exceptions silently.
• Release resources deterministically with try-with-resources or finally.
• Catch exceptions only where you can add context, recover, translate boundary errors, or enforce cleanup.
• Preserve stack traces when wrapping unless there is a deliberate boundary sanitization.
• Do not expose sensitive internal data in exception messages returned to users.
• Define boundary policy for long-running services: discard unit of work, log safely, cleanup, and continue or stop.

Decision Gates

Condition	Action
Resource acquired	Use try-with-resources or explicit finally cleanup.
Caller can recover	Use checked exception or documented recoverable result.
Caller cannot recover	Use unchecked exception or boundary translation.
Exception crosses trust/user boundary	Sanitize message and preserve internal diagnostics safely.
Broad catch appears	Allow only at orchestration boundary with clear policy.

Execution Steps

1. Identify failure sources and recovery owner.
2. Map resource acquisition and release.
3. Choose catch/propagate/wrap/translate behavior.
4. Check message sensitivity and logging policy.
5. Return a robust failure-handling plan or code shape.

Output Contract

Return:

• Failure boundary verdict.
• Exception strategy and recovery owner.
• Resource cleanup requirements.
• Message/logging sensitivity notes.
• Example handling shape when useful.

References

• references/java-exception-guidance.md — Exception choices, cleanup, and boundary policy.

Assets

• None.