https://github.com/szjani/revents
Reactor based CQRS / Event Sourcing framework
https://github.com/szjani/revents
cqrs cqrs-es eventsourcing reactor
Last synced: 3 months ago
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Reactor based CQRS / Event Sourcing framework
- Host: GitHub
- URL: https://github.com/szjani/revents
- Owner: szjani
- License: mit
- Created: 2021-02-06T20:51:51.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2021-03-08T19:27:09.000Z (over 4 years ago)
- Last Synced: 2025-03-03T18:47:52.068Z (8 months ago)
- Topics: cqrs, cqrs-es, eventsourcing, reactor
- Language: Java
- Homepage: https://szjani.github.io/revents/
- Size: 190 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Revents
Revents is an event sourcing framework built on [Project Reactor](https://projectreactor.io/). The codebase is under
heavy development, not production ready yet!
Github pages documentation: https://szjani.github.io/revents/
## Build
Revents requires Java 11.
`./gradlew build`
## Features
- Java configuration via builders
- Spring Boot integration
- Annotation driven
- Reactive
- Supports [Immutables](https://immutables.github.io/)
- Snapshotting (time and event counter based)
- Revision check, optimistic locking
- Event store as queue, event acknowledge (persistent token)
- R2dbc event store and snapshot repository implementation
- MongoDB token store implementation
- Fix and dynamic streams of events
- Customizable and extendable command/event processing flow
- Jackson serialization
- Slf4j MDC population from Reactor context
- In-memory implementations for testing purposes
- `AggregateTestHelper` for behavior testing of aggregates
- Time manipulation during tests
## Example code
```java
@Aggregate
public class Order {
private OrderId orderId;
private OrderState orderState;
@CommandHandler
public Order(CreateOrder createOrder, CommandContext commandContext) {
OrderId orderId = OrderId.generate();
commandContext
.registerAggregateId(Order.class, orderId.asString())
.apply(new OrderCreated(orderId));
}
@CommandHandler
public void handle(ApproveOrder approveOrder, CommandContext commandContext) {
Preconditions.checkState(orderState != OrderState.REJECTED);
commandContext.apply(new OrderApproved(approveOrder.orderId()));
}
@EventHandler
void on(OrderCreated orderCreated) {
orderId = orderCreated.orderId();
orderState = OrderState.CREATED;
}
}
```
```java
@Value.Immutable
public interface ApproveOrder {
@TargetAggregate
OrderId orderId();
@Min(1) //javax.validation
@ExpectedRevision
Long version();
}
```
```java
@EventHandlerBean(processorId = "read-db-sync")
public class OrderProjection {
@EventHandler
public Mono handle(OrderCreated orderCreated, EventContext eventContext) {
return readDb.insert(new OrderProjection(orderCreated.orderId()));
}
}
```
```java
CommandGateway commandGateway = buildCommandGateway();
commandGateway.sendWithResult(new CreateOrder())
.map(CommandResult::aggregateId)
.map(AggregateId::aggregateRootId)
.flatMap(id -> commandGateway.send(ImmutableApproveOrder.builder()
.orderId(OrderId.of(id))
.version(1L)
.build()))
.subscribe();
```
## Creating custom implementations
`revents-contracts` helps you to create your custom implementation of the followings:
- `EventStore`
- `TokenStore`
- `SnapshotRepository`
Extend the corresponding contract test class and ensure your implementation satisfies all the requirements.