net.e6tech.elements.common.notification.NotificationProcessor Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of elements-common Show documentation
elements-common
There is a newer version: 2.7.9
/*
Copyright 2015-2019 Futeh Kao

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 net.e6tech.elements.common.notification;

import net.e6tech.elements.common.actor.GenesisActor;
import net.e6tech.elements.common.inject.Inject;
import net.e6tech.elements.common.logging.Logger;
import net.e6tech.elements.common.resources.Provision;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ExecutorService;

/**
 * Created by futeh.
 */
@SuppressWarnings("unchecked")
public class NotificationProcessor implements NotificationListener {

    private ExecutorService threadPool;
    private GenesisActor genesis;
    private NotificationCenter notificationCenter;
    private Provision provision;

    private Map, Method> methods = new HashMap<>();
    private Class[] notificationTypes = new Class[0];

    public NotificationProcessor() {
        Class cls = getClass();
        List> types = new ArrayList<>();
        while (cls != null && !cls.equals(Object.class)) {
            Method[] methodArray = cls.getDeclaredMethods();
            for (Method method : methodArray) {
                if ("processEvent".equals(method.getName())
                        && method.getParameterCount() == 1
                        && Notification.class.isAssignableFrom(method.getParameterTypes()[0])) {
                    method.setAccessible(true);
                    Class notificationType = (Class) method.getParameterTypes()[0];
                    methods.computeIfAbsent(notificationType, key -> {
                        types.add(notificationType);
                        return method;
                    });
                }
            }
            cls = cls.getSuperclass();
        }
        notificationTypes = types.toArray(new Class[types.size()]);
    }

    public ExecutorService getThreadPool() {
        return threadPool;
    }

    @Inject(optional = true)
    public void setThreadPool(ExecutorService threadPool) {
        this.threadPool = threadPool;
    }

    public GenesisActor getGenesis() {
        return genesis;
    }

    @Inject(optional = true)
    public void setGenesis(GenesisActor genesis) {
        this.genesis = genesis;
    }

    public NotificationCenter getNotificationCenter() {
        return notificationCenter;
    }

    @Inject
    public void setNotificationCenter(NotificationCenter notificationCenter) {
        this.notificationCenter = notificationCenter;
    }

    public Provision getProvision() {
        return provision;
    }

    @Inject
    public void setProvision(Provision provision) {
        this.provision = provision;
    }

    @Override
    public Class[] getNotificationTypes() {
        return notificationTypes;
    }

    /**
     * The onEvent is running on the same thread and using the same Resources as the
     * sender.  This method needs to handle the event fast and schedule longer running task
     * using the run method.
     *
     * @param notification Notification instance
     */
    @Override
    public void onEvent(Notification notification) {
        Class cls = notification.getClass();
        while (!cls.equals(Object.class)) {
            Method method = methods.get(cls);
            if (method != null) {
                try {
                    method.invoke(this, notification);
                } catch (Exception e) {
                    Logger.suppress(e);
                }
                return;
            } else {
                cls = cls.getSuperclass();
            }
        }

        catchEvent(notification);
    }

    /**
     * It is the catch all processEvent method.  It is running on the same thread and using
     * the same Resources as the caller.  Please schedule long running task using the run method.
     * @param notification  Notification instance
     */
    public void catchEvent(Notification notification) {
        // do nothing
    }

    public void async(Runnable runnable) {
        if (genesis != null) {
            genesis.async(runnable);
        } else if (threadPool != null) {
            threadPool.execute(runnable);
        } else {
            Thread thread = new Thread(runnable);
            thread.start();
        }
    }
}