WebFlux

The WebFlux extension provides support for Spring WebFlux, depending on the routing specifications generated by the wow-openapi module, automatically registering command route handlers to implement declarative REST APIs.

Installation

Gradle(Kotlin)

implementation("me.ahoo.wow:wow-webflux")

Gradle(Groovy)

implementation 'me.ahoo.wow:wow-webflux'

Maven

<dependency>
    <groupId>me.ahoo.wow</groupId>
    <artifactId>wow-webflux</artifactId>
    <version>${wow.version}</version>
</dependency>

Automatic Route Registration

The WebFlux extension automatically generates REST API endpoints for all commands:

Route Patterns

Supports multiple route patterns:

Aggregate Route Pattern

@AggregateRoot
@AggregateRoute(owner = AggregateRoute.Owner.AGGREGATE_ID)
class Cart(private val state: CartState)

// Generated route: POST /cart/{cartId}/add_cart_item

Owner Route Pattern

@AggregateRoot
@AggregateRoute(owner = AggregateRoute.Owner.ALWAYS)
class Order(private val state: OrderState)

// Generated route: POST /order/owner/{ownerId}/create_order

HTTP Method Mapping

Command Annotation	HTTP Method	Default Path
@CreateAggregate	POST	/{resource}
@CommandRoute(method = POST)	POST	/{resource}/{command}
@CommandRoute(method = PUT)	PUT	/{resource}/{command}
@CommandRoute(method = DELETE)	DELETE	/{resource}/{command}

Wait Strategy Integration

The WebFlux extension supports specifying wait strategies through HTTP headers:

POST /cart/123/add_cart_item
Content-Type: application/json
Command-Wait-Stage: PROCESSED
Command-Wait-Timeout: 30000

{
  "productId": "product-456",
  "quantity": 2
}

Supported Wait Strategies

• SENT: Command sent
• PROCESSED: Command processed
• PROJECTED: Event projected
• SNAPSHOT: Snapshot created

Error Handling

The WebFlux extension provides unified error response format:

{
  "errorCode": "VALIDATION_ERROR",
  "errorMsg": "Product not found",
  "requestId": "req-123"
}

OpenAPI Integration

Automatically generates OpenAPI documentation:

paths:
  /cart/{cartId}/add_cart_item:
    post:
      summary: "Add item to cart"
      parameters:
        - name: cartId
          in: path
          required: true
          schema:
            type: string
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AddCartItem'

Performance Optimization

Reactive Processing

All endpoints use reactive programming:

@RestController
class CustomController(
    private val commandGateway: CommandGateway
) {

    @PostMapping("/custom/{id}")
    fun customCommand(@PathVariable id: String): Mono<CommandResult> {
        return commandGateway.sendAndWait(
            CustomCommand(id = id),
            WaitStrategy.PROCESSED
        )
    }
}

Connection Pool Configuration

spring:
  codec:
    max-in-memory-size: 10MB
  webflux:
    session:
      timeout: 30m

Monitoring and Debugging

Request Logging

logging:
  level:
    me.ahoo.wow.webflux: DEBUG

Performance Metrics

Automatically collects the following metrics:

• Request latency and throughput
• Error rate statistics
• Wait strategy usage

Best Practices

1. Use Wait Strategies: Choose appropriate wait strategies based on business requirements
2. Error Handling: Implement global exception handlers
3. Security: Enable authentication and authorization checks
4. Monitoring: Configure appropriate log levels and metrics collection
5. Performance: Configure connection pools and timeouts appropriately