org.ops4j.pax.exam.rbc.internal.Activator.java Source code

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Here is the source code for org.ops4j.pax.exam.rbc.internal.Activator.java

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/*
 * Copyright 2008 Toni Menzel
 *
 * 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 org.ops4j.pax.exam.rbc.internal;

import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.concurrent.Callable;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.ops4j.pax.exam.rbc.Constants;
import org.ops4j.pax.swissbox.core.ContextClassLoaderUtils;

/**
 * Registers the an instance of RemoteTestRunnerService as RMI service using a port set by system property
 * pax.exam.communication.port.
 *
 * @author Toni Menzel (tonit)
 * @author Alin Dreghiciu (adreghiciu@gmail.com)
 * @since Jun 2, 2008
 */
public class Activator implements BundleActivator {

    /**
     * JCL logger.
     */
    private static final Log LOG = LogFactory.getLog(Activator.class);

    /**
     * RMI registry.
     */
    private Registry m_registry;
    /**
     * Strong reference to {@link RemoteBundleContext}.
     * !Note: this must be here otherwise JVM will garbage collect it and this will result in an
     * java.rmi.NoSuchObjectException: no such object in table
     */
    private RemoteBundleContext m_remoteBundleContext;

    /**
     * {@inheritDoc}
     */
    public void start(final BundleContext bundleContext) throws Exception {
        //!! Absolutely necessary for RMIClassLoading to work
        ContextClassLoaderUtils.doWithClassLoader(null, // getClass().getClassLoader()
                new Callable<Object>() {
                    public Object call() throws Exception {
                        try {
                            // try to find port from property
                            int port = getPort();
                            m_registry = LocateRegistry.getRegistry(port);
                            LOG.debug("Binding " + RemoteBundleContext.class.getSimpleName() + " to RMI registry");
                            m_registry.bind(RemoteBundleContext.class.getName(), UnicastRemoteObject.exportObject(
                                    m_remoteBundleContext = new RemoteBundleContextImpl(bundleContext), 0));
                            LOG.info("Remote Bundle Context started");
                        } catch (Exception e) {
                            throw new BundleException("Cannot bind RBC to RMI registry", e);
                        }
                        return null;
                    }
                });
    }

    /**
     * {@inheritDoc}
     */
    public void stop(BundleContext bundleContext) throws Exception {
        LOG.debug("Unbinding " + RemoteBundleContext.class.getSimpleName());
        m_registry.unbind(RemoteBundleContext.class.getName());
        UnicastRemoteObject.unexportObject(m_remoteBundleContext, true);
        m_registry = null;
        m_remoteBundleContext = null;
        LOG.info("Remote Bundle Context stopped");
    }

    /**
     * @return the port where {@link RemoteBundleContext} is being exposed as an RMI service.
     *
     * @throws BundleException - If communication port cannot be determined
     */
    private int getPort() throws BundleException {
        // The port is usually given by starting client (owner of this process).
        try {
            return Integer.parseInt(System.getProperty(Constants.RMI_PORT_PROPERTY));
        } catch (NumberFormatException e) {
            throw new BundleException("Cannot determine rmi registry port. Ensure that property "
                    + Constants.RMI_PORT_PROPERTY + " is set to a valid Integer.");
        }
    }
}