| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 javax.enterprise.inject.spi; |
| |
| import java.lang.annotation.Annotation; |
| import java.lang.reflect.Type; |
| import java.util.Set; |
| |
| import javax.enterprise.event.Reception; |
| import javax.enterprise.event.TransactionPhase; |
| |
| /** |
| * <p>ObserverMethod is the SPI to handle an observer method, which is |
| * an event consumer for an event of the given type T. An instance of |
| * ObserverMethod exists for every observer method of every enabled bean.</p> |
| * |
| * <p>A class may have n observer methods.</p> |
| * <p>Each observer method must have a void return value and exactly one parameter |
| * which defines which event it {@code javax.enterprise.event.Observes}. |
| * The observed event may be further specified by using an optional Qualifier.</p> |
| * |
| * Sample: |
| * <pre> |
| * public class UserHandler |
| * { |
| * public void afterUserLogin(@Observes UserLoginEvent userHasLoggedIn) |
| * { |
| * // prepare some data for the user, ... |
| * int userId = userHadLoggedIn.getUserId(); |
| * ... |
| * } |
| * |
| * public void afterAdminLogin(@Observes @Admin UserLoginEvent userHasLoggedIn) |
| * { |
| * // prepare stuff for the admin user |
| * ... |
| * } |
| * |
| * public void afterUserLogout(@Observes UserLogoutEvent userHasLoggedOut) |
| * { |
| * // cleanup afterwards |
| * ... |
| * } |
| * } |
| * </pre> |
| * |
| * @param <T> the event which should be observed |
| * @see javax.enterprise.event.Observes |
| */ |
| public interface ObserverMethod<T> extends Prioritized |
| { |
| /** |
| * The default Priority of any ObserverMethod without a @Priority annotation. |
| */ |
| int DEFAULT_PRIORITY = 2500; |
| |
| Class<?> getBeanClass(); |
| |
| /** |
| * @return the type of the observed event |
| */ |
| Type getObservedType(); |
| |
| /** |
| * @return the defined Qualifiers plus {@code javax.enterprise.inject.Any} |
| */ |
| Set<Annotation> getObservedQualifiers(); |
| |
| /** |
| * @return either {@code Reception#IF_EXISTS} if the observed method must only be called if an instance |
| * of the bean which defines the observer method aready exists in the specified context or {@code Reception#ALWAYS}. |
| */ |
| Reception getReception(); |
| |
| /** |
| * @return the appropriate {@code TransactionPhase} for a transactional observer method or |
| * {@code TransactionPhase#IN_PROGRESS} otherwise. |
| */ |
| TransactionPhase getTransactionPhase(); |
| |
| /** |
| * will actually call the underlying observer method |
| * @param event |
| */ |
| default void notify(T event) |
| { |
| // empty by default |
| } |
| |
| /** |
| * Call the observer method with the given eventContext. |
| * @param eventContext |
| */ |
| default void notify(EventContext<T> eventContext) |
| { |
| if (eventContext != null) |
| { |
| notify(eventContext.getEvent()); |
| } |
| } |
| |
| /** |
| * @return Whether or not this observer method is an async observer. defaults to false for compatibility |
| */ |
| default boolean isAsync() |
| { |
| return false; |
| } |
| |
| /** |
| * Only synchronous ObserverMethods can be ordered! |
| * |
| * @return The @Priority of this ObserverMethod |
| */ |
| default int getPriority() |
| { |
| return DEFAULT_PRIORITY; |
| } |
| |
| |
| } |