Cleanup

org.paramixel.core.support.Cleanup is a small utility for collecting cleanup tasks and running them later.

Main features

• forward or reverse run order
• add plain callbacks
• add AutoCloseable instances
• conditional cleanup with addWhen(...)
• inspect failures via CleanupResult
• throw the first failure with remaining failures suppressed via runAndThrow()

Example

Cleanup cleanup = Cleanup.of(Cleanup.Mode.REVERSE)
        .add(() -> stopServer())
        .addCloseable(network);

CleanupResult result = cleanup.run();

Throwing aggregated failures

Cleanup.of(Cleanup.Mode.FORWARD)
        .addCloseable(resourceA)
        .addCloseable(resourceB)
        .runAndThrow();

runAndThrow() throws the first cleanup failure and attaches later failures as suppressed exceptions.

Re-running and clearing

By default, a Cleanup can only be run once. Calling run() a second time throws IllegalStateException.

• reset() resets the execution state so the same registered tasks can be run again. Registered callbacks are preserved.

Cleanup cleanup = Cleanup.of(Cleanup.Mode.REVERSE)
        .add(() -> stopServer())
        .addCloseable(network);

CleanupResult result = cleanup.run();
// ... inspect result ...

cleanup.reset();              // preserved callbacks can now be re-run
CleanupResult result2 = cleanup.run();

• clear() clears all registered callbacks and resets the execution state. Use this to reuse the same instance from scratch.

Cleanup cleanup = Cleanup.of(Cleanup.Mode.FORWARD)
        .add(() -> stopServer());

cleanup.run();
cleanup.clear();              // callbacks removed, can add new ones
cleanup.add(() -> stopOther()).run();

Fatal errors

OutOfMemoryError and StackOverflowError are not caught by cleanup tasks. If a cleanup task throws either error, the cleanup loop aborts immediately and the error propagates. Other Error subclasses are captured in CleanupResult like other cleanup failures.

Thread safety

Cleanup is not thread-safe. Instances must not be shared across threads or accessed concurrently. Typical usage confines a Cleanup instance to a single lifecycle method pair such as before/after.

Relationship to Container

A common pattern is to create resources in Container.before(...) and release them in Container.after(...) using Cleanup.

See the Testcontainers examples under examples/src/main/java/examples/testcontainers/.