bundlelistenerwrapper.java

OSGI 的 源码实现,采用JAVA书写

/*
 * Oscar - An implementation of the OSGi framework.
 * Copyright (c) 2004, Richard S. Hall
 * All rights reserved.
 *  
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *   * Neither the name of the ungoverned.org nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *  
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * Contact: Richard S. Hall ([e-mail])
 * Contributor(s):
 *
**/
package org.ungoverned.oscar.util;

import java.security.AccessController;
import java.security.PrivilegedAction;

import org.osgi.framework.Bundle;
import org.osgi.framework.BundleEvent;
import org.osgi.framework.BundleListener;
import org.osgi.framework.SynchronousBundleListener;

public class BundleListenerWrapper extends ListenerWrapper implements BundleListener
{
    public BundleListenerWrapper(Bundle bundle, BundleListener l)
    {
        super(bundle,
            (l instanceof SynchronousBundleListener)
                ? SynchronousBundleListener.class : BundleListener.class,
            l);
    }

    public void bundleChanged(final BundleEvent event)
    {
        // A bundle listener is either synchronous or asynchronous.
        // If the bundle listener is synchronous, then deliver the
        // event to bundles with a state of STARTING, STOPPING, or
        // ACTIVE. If the listener is asynchronous, then deliver the
        // event only to bundles that are STARTING or ACTIVE.
        if (((getListenerClass() == SynchronousBundleListener.class) &&
            ((getBundle().getState() == Bundle.STARTING) ||
            (getBundle().getState() == Bundle.STOPPING) ||
            (getBundle().getState() == Bundle.ACTIVE)))
            ||
            ((getBundle().getState() == Bundle.STARTING) ||
            (getBundle().getState() == Bundle.ACTIVE)))
        {
            if (System.getSecurityManager() != null)
            {
                AccessController.doPrivileged(new PrivilegedAction() {
                    public Object run()
                    {
                        ((BundleListener) getListener()).bundleChanged(event);
                        return null;
                    }
                });
            }
            else
            {
                ((BundleListener) getListener()).bundleChanged(event);
            }
        }
    }
}