Cleanup

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

Main features

• forward or reverse execution 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 executables are preserved.

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

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

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

• clear() clears all registered executables 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();              // executables removed, can add new ones
cleanup.add(() -> stopOther()).run();

Fatal errors

Error subclasses (such as OutOfMemoryError, StackOverflowError, ThreadDeath) are not caught by cleanup tasks. If a cleanup task throws an Error, the cleanup loop aborts immediately and the error propagates. Remaining cleanup tasks will not run.

Relationship to Lifecycle

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

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