org.ow2.play.governance.notification.wsn.AbstractSender.java Source code

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Here is the source code for org.ow2.play.governance.notification.wsn.AbstractSender.java

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/**
 *
 * Copyright (c) 2013, Linagora
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
 *
 */
package org.ow2.play.governance.notification.wsn;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;

import javax.xml.namespace.QName;

import org.ow2.play.governance.api.GovernanceExeption;
import org.ow2.play.governance.api.WSNTopicNotificationSender;
import org.ow2.play.governance.api.bean.Topic;
import org.petalslink.dsb.notification.client.http.simple.HTTPConsumerClient;
import org.petalslink.dsb.notification.commons.NotificationException;
import org.w3c.dom.Document;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.cache.RemovalListener;
import com.google.common.cache.RemovalNotification;

/**
 * @author chamerling
 * 
 */
public abstract class AbstractSender implements WSNTopicNotificationSender {

    private LoadingCache<String, HTTPConsumerClient> clients;

    /**
     * 
     */
    public AbstractSender() {
        this.clients = CacheBuilder.newBuilder().maximumSize(100).expireAfterWrite(10L, TimeUnit.MINUTES)
                .removalListener(new RemovalListener<String, HTTPConsumerClient>() {
                    public void onRemoval(RemovalNotification<String, HTTPConsumerClient> notification) {
                        System.out.println("Client removed from cache for endpoint " + notification.getKey());
                    }
                }).build(new CacheLoader<String, HTTPConsumerClient>() {
                    public HTTPConsumerClient load(String endpoint) {
                        System.out.println("Getting new client for endpoint " + endpoint);
                        return new HTTPConsumerClient(endpoint);
                    }
                });
    }

    @Override
    public void notify(String endpoint, Topic topic, String message) throws GovernanceExeption {
        this.send(endpoint, topic, translate(message));
    }

    /**
     * 
     * @param endpoint
     * @param topic
     * @param payload
     */
    protected void send(String endpoint, Topic topic, Document payload) throws GovernanceExeption {
        try {
            this.getClient(endpoint).notify(payload, getQName(topic));
        } catch (NotificationException e) {
            throw new GovernanceExeption("Send message problem", e);
        }
    }

    /**
     * Translate the message into an XML document. Up to the implementation to
     * do it the right way according to their own constraints and rules.
     * 
     * @param message
     * @return
     */
    protected abstract Document translate(String message) throws GovernanceExeption;

    /**
     * Get a WSN client. TODO : Cache it per endpoint (guava)
     * 
     * @param endpoint
     * @return
     */
    protected HTTPConsumerClient getClient(String endpoint) throws GovernanceExeption {
        try {
            return clients.get(endpoint);
        } catch (ExecutionException e) {
            throw new GovernanceExeption("Can not get client from cache", e);
        }
    }

    protected QName getQName(Topic topic) {
        return new QName(topic.getNs(), topic.getName(), topic.getPrefix());
    }

}