com.github.leanframeworks.minibus.api

Interface Topic<C>

Type Parameters:

C - Type of content that can be sent and received on this topic.

All Known Implementing Classes:

SimpleTopic

public interface Topic<C>

Interface to be implemented by topics.

A topic defines the type of content transported by the events.

Method Summary

Modifier and Type	Method and Description
default boolean	covers(Topic<?> topic) States whether this topic covers the specified topics.
default String	getName() Gets the name of the topic (or topic instance), mostly useful for logging/debugging purposes.
default Topic<? super C>	getParentTopic() Gets the parent topic if any.

Method Detail

getName

default String getName()

Gets the name of the topic (or topic instance), mostly useful for logging/debugging purposes.

By default, the class's simple name followed by the instance's hash code.

Returns:

Topic name.

getParentTopic

default Topic<? super C> getParentTopic()

Gets the parent topic if any.

A topic knows its parent, but a parent topic may or may not know their child topics depending on the implementation.

Returns:

Parent topic or null if this topic is a top-level topic.

covers

default boolean covers(Topic<?> topic)

States whether this topic covers the specified topics.

A parent topic covers its child topics. Entities subscribing to a parent topic will receive messages for the parent topic and any of its child topics. For example, if an entity subscribes to event about the "Geography" topic, it will receive messages about "Geography" in general, but also about "France", about "The Netherlands", etc. However, an entity subscribing to events about the "France" topic, it will not receive messages about "Geography" in general or about "The Netherlands".

By default, a topic is covered by its parent topic; and a null topic is covered by nothing.

Note that the implementation should be consistent with getParentTopic().

Parameters:

topic - Topic to be checked (whether it is covered by this topic or not).

Returns:

True if this topic covers the specified topic, false otherwise.

See Also:

getParentTopic()