Package akka.javasdk.evaluation

Class DurableEvaluator<S>

Object

akka.javasdk.evaluation.DurableEvaluator<S>

Type Parameters:

S - The type of the state accumulated across the steps of this evaluation.

public abstract class DurableEvaluator<S>
extends Object

A DurableEvaluator is a stateful component that evaluates agent interactions in multiple steps, with durable execution across those steps.

Use a DurableEvaluator instead of an Evaluator when the evaluation is long-running or needs durable, multi-step execution, for example composed evaluations that accumulate state across several judge calls, or evaluations that wait on human review. Each evaluation runs as its own durable instance: if it is stopped for any reason, it resumes from the last completed step.

Like an Evaluator, a DurableEvaluator is bound to one or more agents through configuration under akka.javasdk.evaluation.evaluators, keyed by the evaluator's component id. The runtime invokes onEvaluation(EvaluationContext) for each interaction of a bound agent. The evaluation then progresses through steps, methods returning DurableEvaluator.Effect, until it finishes with DurableEvaluator.Effect.Builder.complete(akka.javasdk.evaluation.Evaluation) or DurableEvaluator.Effect.Builder.inconclusive(java.lang.String), which records the outcome and cleans up the instance. There is no other way to finish: every evaluation terminates with a recorded outcome, including step failures that exhaust their retries.

Concrete class must be annotated with Component.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	DurableEvaluator.Effect	An Effect is a description of what the runtime needs to do after `onEvaluation` or a step method is handled.
static final class	DurableEvaluator.Settings	Settings for a durable evaluator.
static interface	DurableEvaluator.WithInput<I,R>	Represents an operation that accepts an input of type I and produces a result of type R.

Constructor Summary

Constructors

Constructor	Description
DurableEvaluator()

Method Summary

Modifier and Type	Method	Description
protected final S	currentState()	Returns the state as currently stored.
protected final DurableEvaluator.Effect.Builder<S>	effects()	Returns a builder for the DurableEvaluator.Effect returned by onEvaluation(akka.javasdk.evaluation.EvaluationContext) and step methods.
S	emptyState()	Returns the initial empty state object, passed into the step methods until a new state replaces it.
protected final EvaluationContext	evaluationContext()	The evaluation being run: the subject under evaluation and the evaluation id.
abstract DurableEvaluator.Effect	onEvaluation(EvaluationContext context)	Start the evaluation of the interaction identified by the given context.
DurableEvaluator.Settings	settings()	Override to configure timeouts and retries for this evaluator.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DurableEvaluator

public DurableEvaluator()

Method Details

onEvaluation

public abstract DurableEvaluator.Effect onEvaluation(EvaluationContext context)

Start the evaluation of the interaction identified by the given context. Invoked by the runtime when a trigger fires for this evaluator.

Parameters:

context - identifies the interaction to evaluate

Returns:

an DurableEvaluator.Effect with the first step transition, or directly the outcome

emptyState

public S emptyState()

Returns the initial empty state object, passed into the step methods until a new state replaces it.

The default implementation of this method returns null. It can be overridden to return a more sensible initial state.

currentState

protected final S currentState()

Returns the state as currently stored.

Note that modifying the state directly will not update it in storage. To save the state, one must call effects().updateState().

Throws:

IllegalStateException - if accessed outside a handler method

evaluationContext

protected final EvaluationContext evaluationContext()

The evaluation being run: the subject under evaluation and the evaluation id. Available in onEvaluation(akka.javasdk.evaluation.EvaluationContext) and in every step method.

Throws:

IllegalStateException - if accessed outside a handler method

effects

protected final DurableEvaluator.Effect.Builder<S> effects()

Returns a builder for the DurableEvaluator.Effect returned by onEvaluation(akka.javasdk.evaluation.EvaluationContext) and step methods.

settings

public DurableEvaluator.Settings settings()

Override to configure timeouts and retries for this evaluator.