org.hibernate.event.service.spi.EventListenerGroup Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of hibernate-core Show documentation
Show all versions of hibernate-core Show documentation
Hibernate's core ORM functionality
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* License: GNU Lesser General Public License (LGPL), version 2.1 or later.
* See the lgpl.txt file in the root directory or .
*/
package org.hibernate.event.service.spi;
import java.io.Serializable;
import java.util.Map;
import java.util.concurrent.CompletionStage;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Function;
import java.util.function.Supplier;
import org.hibernate.Incubating;
import org.hibernate.event.spi.EventType;
/**
* Contract for a groups of events listeners for a particular event type.
*
* @author Steve Ebersole
*/
public interface EventListenerGroup extends Serializable {
/**
* Retrieve the event type associated with this groups of listeners.
*
* @return The event type.
*/
public EventType getEventType();
/**
* Are there no listeners registered?
*
* @return {@literal true} if no listeners are registered; {@literal false} otherwise.
*/
public boolean isEmpty();
public int count();
/**
* @deprecated this is not the most efficient way for iterating the event listeners.
* See {@link #fireEventOnEachListener(Object, BiConsumer)} and its overloaded variants for better alternatives.
* @return The Iterable.
*/
@Deprecated
public Iterable listeners();
/**
* Mechanism to more finely control the notion of duplicates.
*
* For example, say you are registering listeners for an extension library. This extension library
* could define a "marker interface" which indicates listeners related to it and register a strategy
* that checks against that marker interface.
*
* @param strategy The duplication strategy
*/
public void addDuplicationStrategy(DuplicationStrategy strategy);
public void appendListener(T listener);
public void appendListeners(T... listeners);
public void prependListener(T listener);
public void prependListeners(T... listeners);
/**
* Clears both the list of event listeners and all DuplicationStrategy,
* including the default duplication strategy.
* @deprecated likely want to use {@link #clearListeners()} instead, which doesn't
* also reset the registered DuplicationStrategy(ies).
*/
@Deprecated
public void clear();
/**
* Removes all registered listeners
*/
public void clearListeners();
/**
* Fires an event on each registered event listener of this group.
*
* Implementation note (performance):
* the first argument is a supplier so that events can avoid being created when no listener is registered.
* the second argument is specifically designed to avoid needing a capturing lambda.
*
* @param eventSupplier
* @param actionOnEvent
* @param the kind of event
*/
@Incubating
void fireLazyEventOnEachListener(final Supplier eventSupplier, final BiConsumer actionOnEvent);
/**
* Similar as {@link #fireLazyEventOnEachListener(Supplier, BiConsumer)} except it doesn't use a {{@link Supplier}}:
* useful when there is no need to lazily initialize the event.
* @param event
* @param actionOnEvent
* @param the kind of event
*/
@Incubating
void fireEventOnEachListener(final U event, final BiConsumer actionOnEvent);
/**
* Similar to {@link #fireEventOnEachListener(Object, BiConsumer)}, but allows passing a third parameter
* to the consumer; our code based occasionally needs a third parameter: having this additional variant
* allows using the optimal iteration more extensively and reduce allocations.
* @param event
* @param param
* @param actionOnEvent
* @param
* @param
*/
@Incubating
void fireEventOnEachListener(final U event, X param, final EventActionWithParameter actionOnEvent);
/**
* Similar to {@link #fireEventOnEachListener(Object, Function)}, but Reactive friendly: it chains
* processing of the same event on each Reactive Listener, and returns a {@link CompletionStage} of type R.
* The various generic types allow using this for each concrete event type and flexible return types.
* Used by Hibernate Reactive
* @param event The event being fired
* @param fun The function combining each event listener with the event
* @param the return type of the returned CompletionStage
* @param the type of the event being fired on each listener
* @param the type of ReactiveListener: each listener of type T will be casted to it.
* @return the composite completion stage of invoking fun(event) on each listener.
*/
@Incubating
CompletionStage fireEventOnEachListener(final U event, final Function>> fun);
/**
* Similar to {@link #fireEventOnEachListener(Object, Object, Function)}, but Reactive friendly: it chains
* processing of the same event on each Reactive Listener, and returns a {@link CompletionStage} of type R.
* The various generic types allow using this for each concrete event type and flexible return types.
* Used by Hibernate Reactive
* @param event The event being fired
* @param fun The function combining each event listener with the event
* @param the return type of the returned CompletionStage
* @param the type of the event being fired on each listener
* @param the type of ReactiveListener: each listener of type T will be casted to it.
* @param an additional parameter to be passed to the function fun
* @return the composite completion stage of invoking fun(event) on each listener.
*/
@Incubating
public CompletionStage fireEventOnEachListener(U event, X param, Function>> fun);
/**
* Similar to {@link #fireLazyEventOnEachListener(Supplier, BiConsumer)}, but Reactive friendly: it chains
* processing of the same event on each Reactive Listener, and returns a {@link CompletionStage} of type R.
* The various generic types allow using this for each concrete event type and flexible return types.
* This variant expects a Supplier of the event, rather than the event directly; this is useful for the
* event types which are commonly configured with no listeners at all, so to allow skipping creating the
* event; use only for event types which are known to be expensive while the listeners are commonly empty.
* Used by Hibernate Reactive
* @param eventSupplier A supplier able to produce the actual event
* @param fun The function combining each event listener with the event
* @param the return type of the returned CompletionStage
* @param the type of the event being fired on each listener
* @param the type of ReactiveListener: each listener of type T will be casted to it.
* @return the composite completion stage of invoking fun(event) on each listener.
*/
@Incubating
CompletionStage fireLazyEventOnEachListener(final Supplier eventSupplier, final Function>> fun);
}