pekko-sample-persistence-java/README.md - pekko-samples - Git at Google

 This example illustrates event sourcing with [Apache Pekko Persistence](https://pekko.apache.org/docs/pekko/current/typed/persistence.html).

 Study the source code of the [ShoppingCart.scala](src/main/java/sample/persistence/ShoppingCart.java). A few things
 to note:

 * The actor is implemented with the `EventSourcedBehavior`
 * It defines `Command`, `Event` and `State`
 * Commands define `replyTo: ActorRef` to send a confirmation when the event has been successfully persisted
 * `State` is only updated in the event handler
 * `withRetention` to enable [snapshotting](https://pekko.apache.org/docs/pekko/current/typed/persistence-snapshot.html)
 * `onPersistFailure` defines restarts with backoff in case of failures

 Tests are defined in [ShoppingCartTest.java](src/test/java/sample/persistence/ShoppingCartTest.java).
 To run the tests, enter:

 ```
 mvn test
 ```

 The `ShoppingCart` application is expanded further in the `pekko-sample-cqrs-java` sample. In that sample the events are tagged to be consumed by even processors to build other representations from the events, or publish the events to other services.
	This example illustrates event sourcing with [Apache Pekko Persistence](https://pekko.apache.org/docs/pekko/current/typed/persistence.html).

	Study the source code of the [ShoppingCart.scala](src/main/java/sample/persistence/ShoppingCart.java). A few things
	to note:

	* The actor is implemented with the `EventSourcedBehavior`
	* It defines `Command`, `Event` and `State`
	* Commands define `replyTo: ActorRef` to send a confirmation when the event has been successfully persisted
	* `State` is only updated in the event handler
	* `withRetention` to enable [snapshotting](https://pekko.apache.org/docs/pekko/current/typed/persistence-snapshot.html)
	* `onPersistFailure` defines restarts with backoff in case of failures

	Tests are defined in [ShoppingCartTest.java](src/test/java/sample/persistence/ShoppingCartTest.java).
	To run the tests, enter:

	```
	mvn test
	```

	The `ShoppingCart` application is expanded further in the `pekko-sample-cqrs-java` sample. In that sample the events are tagged to be consumed by even processors to build other representations from the events, or publish the events to other services.