ApplicationRunListeners class final

Coordinates the execution of multiple ApplicationRunListener instances during the JetLeaf application lifecycle.

This class serves as the central event dispatcher for JetLeaf’s bootstrap process, invoking each registered listener in sequence as the application progresses through its various lifecycle stages (e.g., startup, environment preparation, context initialization, readiness, and failure).

The ApplicationRunListeners implementation ensures that all listeners execute safely and that failures in one listener do not prevent others from being notified. It also integrates with ApplicationStartup to record structured startup metrics for performance analysis and debugging.

Example

final listeners = ApplicationRunListeners(
  [MyStartupListener(), MyTelemetryListener()],
  DefaultApplicationStartup(),
);

listeners.onStarting(context, Class<MyApp>(MyApp));
listeners.onEnvironmentPrepared(context, environment);
listeners.onStarted(context, Duration(milliseconds: 850));

Key Responsibilities

• Dispatches lifecycle events to registered ApplicationRunListeners.
• Records structured startup telemetry through ApplicationStartup.
• Gracefully handles listener exceptions during startup and shutdown.
• Provides internal error logging via JetLeaf’s LogFactory.

JetLeaf developers typically do not instantiate this class directly. Instead, the framework constructs it automatically during application boot.