11d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/* 21d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Copyright (C) 2007 The Guava Authors 31d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 41d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Licensed under the Apache License, Version 2.0 (the "License"); 51d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * you may not use this file except in compliance with the License. 61d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * You may obtain a copy of the License at 71d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 81d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * http://www.apache.org/licenses/LICENSE-2.0 91d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 101d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Unless required by applicable law or agreed to in writing, software 111d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * distributed under the License is distributed on an "AS IS" BASIS, 121d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 131d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * See the License for the specific language governing permissions and 141d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * limitations under the License. 151d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 161d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 171d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertpackage com.google.common.eventbus; 181d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 191d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.HashMultimap; 201d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport com.google.common.collect.Multimap; 211d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertimport java.lang.reflect.Method; 221d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 231d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert/** 241d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * A {@link HandlerFindingStrategy} for collecting all event handler methods 251d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * that are marked with the {@link Subscribe} annotation. 261d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 271d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @author Cliff Biffle 281d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 291d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringertclass AnnotatedHandlerFinder implements HandlerFindingStrategy { 301d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 311d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 321d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@inheritDoc} 331d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 341d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * This implementation finds all methods marked with a {@link Subscribe} 351d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * annotation. 361d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 371d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert @Override 381d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert public Multimap<Class<?>, EventHandler> findAllHandlers(Object listener) { 391d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Multimap<Class<?>, EventHandler> methodsInListener = 401d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert HashMultimap.create(); 411d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Class clazz = listener.getClass(); 421d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert while (clazz != null) { 431d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert for (Method method : clazz.getMethods()) { 441d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Subscribe annotation = method.getAnnotation(Subscribe.class); 451d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 461d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (annotation != null) { 471d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Class<?>[] parameterTypes = method.getParameterTypes(); 481d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (parameterTypes.length != 1) { 491d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert throw new IllegalArgumentException( 501d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert "Method " + method + " has @Subscribe annotation, but requires " + 511d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert parameterTypes.length + " arguments. Event handler methods " + 521d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert "must require a single argument."); 531d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 541d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert Class<?> eventType = parameterTypes[0]; 551d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert EventHandler handler = makeHandler(listener, method); 561d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 571d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert methodsInListener.put(eventType, handler); 581d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 591d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 601d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert clazz = clazz.getSuperclass(); 611d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 621d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return methodsInListener; 631d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 641d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 651d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 661d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Creates an {@code EventHandler} for subsequently calling {@code method} on 671d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code listener}. 681d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Selects an EventHandler implementation based on the annotations on 691d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code method}. 701d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 711d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @param listener object bearing the event handler method. 721d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @param method the event handler method to wrap in an EventHandler. 731d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return an EventHandler that will call {@code method} on {@code listener} 741d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * when invoked. 751d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 761d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static EventHandler makeHandler(Object listener, Method method) { 771d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert EventHandler wrapper; 781d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert if (methodIsDeclaredThreadSafe(method)) { 791d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert wrapper = new EventHandler(listener, method); 801d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } else { 811d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert wrapper = new SynchronizedEventHandler(listener, method); 821d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 831d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return wrapper; 841d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 851d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert 861d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert /** 871d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * Checks whether {@code method} is thread-safe, as indicated by the 881d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@link AllowConcurrentEvents} annotation. 891d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * 901d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @param method handler method to check. 911d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * @return {@code true} if {@code handler} is marked as thread-safe, 921d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert * {@code false} otherwise. 931d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert */ 941d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert private static boolean methodIsDeclaredThreadSafe(Method method) { 951d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert return method.getAnnotation(AllowConcurrentEvents.class) != null; 961d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert } 971d580d0f6ee4f21eb309ba7b509d2c6d671c4044Bjorn Bringert} 98