AgentManager.java

/*
 * Copyright (c) 2006-2009 by Dirk Riehle, http://dirkriehle.com
 *
 * This file is part of the Wahlzeit photo rating application.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 */

package org.wahlzeit.agents;

import org.wahlzeit.services.LogBuilder;

import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;

/**
 * The AgentManager singleton manages all Agent instances.
 */
public class AgentManager {

	private static Logger log = Logger.getLogger(AgentManager.class.getName());

	/**
	 *
	 */
	protected static AgentManager instance = null;

	/**
	 * @methodtype initialization
	 */
	protected static void initInstance() {
		getInstance().addAgent(new NotifyUsersAboutPraiseAgent());
	}

	/**
	 * @methodtype get
	 */
	public static synchronized AgentManager getInstance() {
		if (instance == null) {
			instance = new AgentManager();
			initInstance();
		}
		return instance;
	}

	/**
	 *
	 */
	protected Map<String, Agent> agents = new HashMap<String, Agent>();

	/**
	 *
	 */
	protected AgentManager() {
		// do nothing
	}

	/**
	 * @methodtype get
	 */
	public Agent getAgent(String name) {
		return agents.get(name);
	}

	/**
	 * @methodtype set
	 */
	public void addAgent(Agent agent) {
		String name;
		synchronized (agent) {
			name = agent.getName();
			agents.put(name, agent);
		}
		log.config(LogBuilder.createSystemMessage().addMessage("agent added").addParameter("name", name).toString());
	}

	/**
	 * @methodtype command
	 */
	public void startAgent(String agentName) throws IllegalArgumentException {
		Agent agent = getAgent(agentName);
		if (agent != null) {
			agent.run();
		} else {
			throw new IllegalArgumentException("Unknown agent name: " + agentName);
		}
	}

}