Handler Registry

Before start handling DomainEvents, Commands or Async Queries you should know a HandlerRegistry abstraction which enables you the ability to register what kind of these items can handle or serve.

API specification

HandlerRegistry

This abstraction allows you to register all kind of events, commands, queries and notification events that your application can handle, for each of them there is a method.

The next methods are the main methods that you can use to register a handler.

public class HandlerRegistry {
    // events: DomainEvent
    public <T> HandlerRegistry listenEvent(String eventName, DomainEventHandler<T> handler, Class<T> eventClass)
    public <T> HandlerRegistry listenDomainEvent(String domain, String eventName, DomainEventHandler<T> handler, Class<T> eventClass)

    // events: CloudEvent
    public HandlerRegistry listenCloudEvent(String eventName, CloudEventHandler handler)
    public HandlerRegistry listenDomainCloudEvent(String domain, String eventName, CloudEventHandler handler)

    // events: RawMessage
    public HandlerRegistry listenRawEvent(String eventName, RawEventHandler<?> handler)
    public HandlerRegistry listenDomainRawEvent(String domain, String eventName, RawEventHandler<?> handler)

    // notifications: DomainEvent
    public <T> HandlerRegistry listenNotificationEvent(String eventName, DomainEventHandler<T> handler, Class<T> eventClass)
    public <T> HandlerRegistry listenNotificationEvent(String domain, String eventName, DomainEventHandler<T> handler, Class<T> eventClass)

    // notifications: CloudEvent
    public HandlerRegistry listenNotificationCloudEvent(String eventName, CloudEventHandler handler)
    public HandlerRegistry listenNotificationCloudEvent(String domain, String eventName, CloudEventHandler handler)

    // notifications: RawMessage
    public HandlerRegistry listenNotificationRawEvent(String eventName, RawEventHandler<?> handler)
    public HandlerRegistry listenNotificationRawEvent(String domain, String eventName, RawEventHandler<?> handler)

    // dynamic: DomainEvent supported only for default domain
    public <T> HandlerRegistry handleDynamicEvents(String eventNamePattern, DomainEventHandler<T> handler, Class<T> eventClass)

    // dynamic: CloudEvent supported only for default domain
    public HandlerRegistry handleDynamicCloudEvents(String eventNamePattern, CloudEventHandler handler)

    // commands: Command
    public <T> HandlerRegistry handleCommand(String commandName, DomainCommandHandler<T> fn, Class<T> commandClass)
    public <T> HandlerRegistry handleCommand(String domain, String commandName, DomainCommandHandler<T> fn, Class<T> commandClass)

    // commands: CloudEvent
    public HandlerRegistry handleCloudEventCommand(String commandName, CloudCommandHandler handler)
    public HandlerRegistry handleCloudEventCommand(String domain, String commandName, CloudCommandHandler handler)

    // commands: RawMessage
    public HandlerRegistry handleRawCommand(String commandName, RawCommandHandler<?> handler)
    public HandlerRegistry handleRawCommand(String domain, String commandName, RawCommandHandler<?> handler)

    // queries: Query
    public <T, R> HandlerRegistry serveQuery(String resource, QueryHandler<T, R> handler, Class<R> queryClass)
    public <R> HandlerRegistry serveQuery(String resource, QueryHandlerDelegate<Void, R> handler, Class<R> queryClass)
    public <R> HandlerRegistry serveCloudEventQuery(String resource, QueryHandler<R, CloudEvent> handler)
    public HandlerRegistry serveCloudEventQuery(String resource, QueryHandlerDelegate<Void, CloudEvent> handler)
}

Methods that Has CloudEvent in the name are related to the CloudEvent specification.

Methods that has domain String argument are related to the multi-broker support, this support is limited to listen events from different domains (brokers) independent of the technology.