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* Copyright 2010, 2015 Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package jakarta.enterprise.inject.spi;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.util.Set;
import jakarta.enterprise.event.ObservesAsync;
import jakarta.enterprise.event.Reception;
import jakarta.enterprise.event.TransactionPhase;
import jakarta.enterprise.event.Observes;
/**
*
* Represents an {@linkplain Observes observer method} of an {@linkplain jakarta.enterprise.inject enabled
* bean}. Defines everything the container needs to know about an observer method.
*
*
*
* If a custom implementation of this interface does not override either {@link #notify(Object)} or
* {@link #notify(EventContext)}, the container automatically detects the problem and treats it as a definition error.
*
*
* @author Gavin King
* @author David Allen
* @author Mark Paluch
* @author Antoine Sabot-Durand
* @param the event type
*/
public interface ObserverMethod extends Prioritized {
public static final int DEFAULT_PRIORITY = jakarta.interceptor.Interceptor.Priority.APPLICATION + 500;
/**
*
* Obtains the {@linkplain Class class} of the type that declares the observer method.
*
*
* @return the defining {@linkplain Class class}
*/
public Class getBeanClass();
/**
*
* Obtains the {@linkplain Bean bean} that declares the observer method.
* For synthetic observers, the return value is undefined.
*
*
*
* For the sake of compatibility with existing custom {@link ObserverMethod} implementations, this method by default
* returns {@code null}.
*
*
* @return the declaring {@linkplain Bean bean}
*/
default Bean getDeclaringBean() {
return null;
}
/**
* Obtains the {@linkplain jakarta.enterprise.event observed event type}.
*
* @return the observed event {@linkplain Type type}
*/
public Type getObservedType();
/**
* Obtains the set of {@linkplain jakarta.enterprise.event observed event qualifiers}.
*
* @return the observed event {@linkplain jakarta.inject.Qualifier qualifiers}
*/
public Set getObservedQualifiers();
/**
* Obtains the specified {@link Reception} for the observer method. This indicates if the observer is conditional or not.
*
* @return the {@link Reception}
*/
public Reception getReception();
/**
* Obtains the specified {@link TransactionPhase} for the observer method.
*
* @return the {@link TransactionPhase}
*/
public TransactionPhase getTransactionPhase();
/**
* The priority that will be used by the container to determine the notification order in which event observer
* methods are invoked.
*
* @return The priority that will be used by the container to determine the notification order in which event
* observer methods are invoked.
* @since 2.0
*/
@Override
public default int getPriority() {
return DEFAULT_PRIORITY;
}
/**
*
* Calls the observer method, passing the given event object.
*
*
*
* The implementation of this method for a custom observer method is responsible for deciding whether to call
* the method if the {@link #getReception()} returns {@link Reception#IF_EXISTS}.
*
*
* @param event the event object
*/
public default void notify(T event) {
}
/**
* Calls the observer method, passing the given event context.
*
* The container should always call this method, but the default implementation delegates to {@link #notify(Object)}.
*
* The implementation of this method for a custom observer method is responsible for deciding whether to call the method if
* the {@link #getReception()} returns {@link Reception#IF_EXISTS}.
*
* @param eventContext {@link EventContext} used to notify observers
*/
public default void notify(EventContext eventContext) {
notify(eventContext.getEvent());
}
/**
*
* Determines if this observer method is asynchronous
*
*
* @return returns true if the method is an asynchronous observer method (i.e. defined with {@link ObservesAsync}),
* otherwise returns false
*
*/
public default boolean isAsync() {
return false;
}
}