Ensure¶

Overview¶

The ensure package provides the return types for the 16 idempotent ensure methods on MqRestSession. These methods implement a declarative upsert pattern: DEFINE if the object does not exist, ALTER only attributes that differ, or no-op if the object already matches the desired state.

EnsureAction¶

An enum indicating the action taken by an ensure method:

public enum EnsureAction {
    CREATED,    // Object did not exist; DEFINE was issued
    UPDATED,    // Object existed but attributes differed; ALTER was issued
    UNCHANGED   // Object already matched the desired state
}

EnsureResult¶

A record containing the action taken and the list of attribute names that triggered the change (if any):

public record EnsureResult(
    EnsureAction action,
    List<String> changed    // attribute names that differed (empty for CREATED/UNCHANGED)
) {}

Method	Return type	Description
`action()`	`EnsureAction`	What happened: `CREATED`, `UPDATED`, or `UNCHANGED`
`changed()`	`List<String>`	Attribute names that triggered an ALTER (in the caller's namespace)

Usage¶

EnsureResult result = session.ensureQlocal("MY.QUEUE",
    Map.of("max_queue_depth", 50000, "description", "App queue"));

switch (result.action()) {
    case CREATED   -> System.out.println("Queue created");
    case UPDATED   -> System.out.println("Changed: " + result.changed());
    case UNCHANGED -> System.out.println("Already correct");
}

See Ensure Methods for the full conceptual overview, comparison logic, and the complete list of available ensure methods.