console/src/main/java/org/apache/felix/gogo/console/Activator.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.felix.gogo.console;

import org.apache.felix.gogo.console.stdio.StdioConsole;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.service.command.CommandProcessor;
import org.osgi.util.tracker.ServiceTracker;

public class Activator implements BundleActivator
{

    private ServiceTracker commandProcessorTracker;
    private StdioConsole console;

    public void start(final BundleContext context) throws Exception
    {
        commandProcessorTracker = new ServiceTracker(context, CommandProcessor.class.getName(), null) {
            @Override
            public Object addingService(ServiceReference reference)
            {
                CommandProcessor processor = (CommandProcessor) super.addingService(reference);
                startConsole(processor);
                return processor;
            }

            @Override
            public void removedService(ServiceReference reference, Object service)
            {
                if (console != null) {
                    console.close();
                    console = null;
                }
                super.removedService(reference, service);
            }
        };
        commandProcessorTracker.open();
    }

    protected void startConsole(final CommandProcessor processor) {
        console = new StdioConsole();
        console.setProcessor(processor);
        console.start();
    }

    public void stop(BundleContext context) throws Exception
    {
        if (console != null) {
            console.close();
        }
        commandProcessorTracker.close();
    }

}