AbstractSpringContextJmxServiceDaemon.java

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 * This file is part of OpenNMS(R).
 *
 * Copyright (C) 2008-2011 The OpenNMS Group, Inc.
 * OpenNMS(R) is Copyright (C) 1999-2011 The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is a registered trademark of The OpenNMS Group, Inc.
 *
 * OpenNMS(R) is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published
 * by the Free Software Foundation, either version 3 of the License,
 * or (at your option) any later version.
 *
 * OpenNMS(R) 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenNMS(R).  If not, see:
 *      http://www.gnu.org/licenses/
 *
 * For more information contact:
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package org.opennms.netmgt.daemon;

import java.lang.reflect.UndeclaredThrowableException;

import org.opennms.core.fiber.Fiber;
import org.opennms.core.utils.BeanUtils;
import org.opennms.core.utils.ThreadCategory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * <p>Abstract AbstractSpringContextJmxServiceDaemon class.</p>
 *
 * @author <a href="mailto:brozow@opennms.org">Mathew Brozowski</a>
 * @author <a href="mailto:dj@opennms.org">DJ Gregor</a>
 */
public abstract class AbstractSpringContextJmxServiceDaemon<T extends SpringServiceDaemon> implements BaseOnmsMBean {

    /** Constant <code>DAEMON_BEAN_NAME="daemon"</code> */
    public static final String DAEMON_BEAN_NAME = "daemon";

    private ClassPathXmlApplicationContext m_context;

    private int m_status = Fiber.START_PENDING;

    /**
     * <p>Constructor for AbstractSpringContextJmxServiceDaemon.</p>
     *
     * @param <T> a T object.
     */
    public AbstractSpringContextJmxServiceDaemon() {
        super();
    }
    
    /**
     * <p>getSpringContext</p>
     *
     * @return a {@link java.lang.String} object.
     */
    protected abstract String getSpringContext();

    /**
     * <p>getLoggingPrefix</p>
     *
     * @return a {@link java.lang.String} object.
     */
    protected abstract String getLoggingPrefix();

    /**
     * This is here for unit tests to use.
     *
     * @return a {@link org.springframework.context.ApplicationContext} object.
     */
    protected ApplicationContext getContext() {
        return m_context;
    }
    
    /**
     * <p>init</p>
     */
    public final void init() {
        setLoggingCategory();
  
        log().debug("SPRING: thread.classLoader=" + Thread.currentThread().getContextClassLoader());

        m_context = BeanUtils.getFactory(getSpringContext(), ClassPathXmlApplicationContext.class);

        log().debug("SPRING: context.classLoader= "+ m_context.getClassLoader());
    }
    
    /**
     * <p>start</p>
     */
    public final void start() {
        setLoggingCategory();
        
        setStatus(Fiber.STARTING);
        SpringServiceDaemon daemon = getDaemon();
        try {
            daemon.start();
        } catch (Throwable t) {
            log().error("Could not start daemon: " + t, t);
            
            try {
                stop();
            } catch (Throwable tt) {
                log().error("Could not stop daemon after it failed to start: " + tt, tt);
            }
            
            if (t instanceof RuntimeException) {
                throw (RuntimeException) t;
            } else {
                throw new UndeclaredThrowableException(t);
            }
        }
        setStatus(Fiber.RUNNING);
    }

    /**
     * Get the service daemon object that this JMX MBean represents.
     *
     * @return the service daemon object
     */
    @SuppressWarnings("unchecked")
    public T getDaemon() {
        return (T) m_context.getBean(DAEMON_BEAN_NAME, SpringServiceDaemon.class);
    }

    /**
     * <p>stop</p>
     */
    public final void stop() {
        setLoggingCategory();
        
        setStatus(Fiber.STOP_PENDING);

        if (m_context != null) {
            m_context.close();
        }
        
        setStatus(Fiber.STOPPED);
    }

    /**
     * <p>getStatus</p>
     *
     * @return a int.
     */
    public final int getStatus() {
        return m_status;
    }

    private void setStatus(int status) {
        m_status = status;
    }

    /**
     * <p>status</p>
     *
     * @return a {@link java.lang.String} object.
     */
    public final String status() {
        setLoggingCategory();
        
        return Fiber.STATUS_NAMES[getStatus()];
    }

    /**
     * <p>getStatusText</p>
     *
     * @return a {@link java.lang.String} object.
     */
    public final String getStatusText() {
        return status();
    }

    private ThreadCategory log() {
        return ThreadCategory.getInstance();
    }

    private void setLoggingCategory() {
        ThreadCategory.setPrefix(getLoggingPrefix());
    }
}