Pousse-Cafe-Spring

This project provides a bridge between Pousse-Café and Spring. It enables the injection of Pousse-Café components into Spring beans. For instance, you can use Spring's @Autowired annotation to inject one of your Pousse-Café repositories into a Spring REST controller (i.e. a bean annotated with @RestController).

It also enables the injection of Spring beans in some Pousse-Café components:

• Services,
• Repositories,
• Data Accesses,
• Factories,
• TransactionRunner,
• MessageSendingPolicy.

Note that injecting Spring Beans in Domain components is not recommended as you might mix up non-domain and domain logic. In some particular cases however, this might be the preferred approach (e.g. when domain services rely on non-domain features like sending e-mails, etc.).

Below an example of configuration file to add to your application in order to automatically build and start a Pousse-Café Runtime:

@Configuration
@Import(RuntimeConfiguration.class) // Enables the bridge
public class YourConfiguration {

    @Override
    protected Bundles bundles(Messaging messaging,
            Storage storage) {
        MessagingAndStorage messagingAndStorage = new MessagingAndStorage(messaging, storage);
        return new Bundles.Builder()
            // Register your bundles here using withBundle and use messagingAndStorage
            // when building them
            .build();
    }
}

Note that if you are using a custom Messaging and/or Storage, you'll have to use the specific types for bundles method's arguments.

Finally, note that a Spring Bean may define custom message listeners (i.e. contain methods annotated with @MessageListener). In that case, extending MessageListeningBean automatically registers the listeners upon Bean's initialization.

Properties

The following properties are used to customize Pousse-Café Runtime:

• poussecafe.core.failOnDeserializationError: flag telling of deserialization errors should be considered as failures or not (default is false)
• poussecafe.core.processingThreads: the number of processing threads to start for message consumption (default is 1)
• poussecafe.core.consumptionMaxRetries: the maximum number of consumption retries in case of collision (default is 50)
• poussecafe.core.consumptionBackOffCeiling: the ceiling for back-off algorithm in case of collision (default is 10)
• poussecafe.core.consumptionBackOffSlotTime: the slot time for back-off algorithm in case of collision (default is 3.0)

Also, properties with keys starting with poussecafe.config. are automatically added to Runtime's configuration. For example, property poussecafe.config.X = Y will cause configuration to contain have value Y with key X.

Configure your Maven project

Add the following snippet to your POM:

<dependency>
    <groupId>org.pousse-cafe-framework</groupId>
    <artifactId>pousse-cafe-spring</artifactId>
    <version>${poussecafe.spring.version}</version>
</dependency>