org.elasticsoftware.elasticactors.runtime.PluggableMessageHandlersScanner.java Source code

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Here is the source code for org.elasticsoftware.elasticactors.runtime.PluggableMessageHandlersScanner.java

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/*
 * Copyright 2013 - 2017 The Original Authors
 *
 * 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 org.elasticsoftware.elasticactors.runtime;

import com.google.common.collect.LinkedListMultimap;
import com.google.common.collect.ListMultimap;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsoftware.elasticactors.*;
import org.reflections.Reflections;
import org.reflections.util.ClasspathHelper;
import org.reflections.util.ConfigurationBuilder;
import org.springframework.context.ApplicationContext;

import javax.annotation.PostConstruct;
import javax.inject.Inject;
import javax.inject.Named;
import java.util.List;
import java.util.Set;

/**
 * Find all classes annotated with {@link PluggableMessageHandlers} and add them to the registry
 *
 * @author Joost van de Wijgerd
 */
@Named
public final class PluggableMessageHandlersScanner
        implements MessageHandlersRegistry, ActorLifecycleListenerRegistry {
    private static final Logger logger = LogManager.getLogger(PluggableMessageHandlersScanner.class);
    @Inject
    private ApplicationContext applicationContext;
    private final ListMultimap<Class<? extends MethodActor>, Class<?>> registry = LinkedListMultimap.create();
    private final ListMultimap<Class<? extends ElasticActor>, ActorLifecycleListener<?>> lifecycleListeners = LinkedListMultimap
            .create();

    @PostConstruct
    public void init() {
        String[] basePackages = ScannerHelper.findBasePackagesOnClasspath(applicationContext.getClassLoader());
        ConfigurationBuilder configurationBuilder = new ConfigurationBuilder();

        for (String basePackage : basePackages) {
            configurationBuilder.addUrls(ClasspathHelper.forPackage(basePackage));
        }

        Reflections reflections = new Reflections(configurationBuilder);

        Set<Class<?>> handlerClasses = reflections.getTypesAnnotatedWith(PluggableMessageHandlers.class);

        for (Class<?> handlerClass : handlerClasses) {
            PluggableMessageHandlers handlerAnnotation = handlerClass.getAnnotation(PluggableMessageHandlers.class);
            registry.put(handlerAnnotation.value(), handlerClass);
        }

        Set<Class<? extends ActorLifecycleListener>> listenerClasses = reflections
                .getSubTypesOf(ActorLifecycleListener.class);
        for (Class<? extends ActorLifecycleListener> listenerClass : listenerClasses) {
            try {
                ActorLifecycleListener lifeCycleListener = listenerClass.newInstance();
                // ensure that the lifeCycle listener handles the correct state class
                lifecycleListeners.put(lifeCycleListener.getActorClass(), lifeCycleListener);
            } catch (Exception e) {
                logger.error("Exception while instantiating ActorLifeCycleListener", e);
            }
        }
    }

    @Override
    public List<Class<?>> getMessageHandlers(Class<? extends MethodActor> methodActor) {
        return registry.get(methodActor);
    }

    @Override
    public List<ActorLifecycleListener<?>> getListeners(Class<? extends ElasticActor> actorClass) {
        return lifecycleListeners.get(actorClass);
    }

}