001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017
018package org.apache.logging.log4j.util;
019
020import java.util.Hashtable;
021
022import org.apache.logging.log4j.spi.Provider;
023import org.osgi.framework.BundleActivator;
024import org.osgi.framework.BundleContext;
025import org.osgi.framework.ServiceRegistration;
026
027/**
028 * Utility class to register Log4j2 providers in an OSGI environment.
029 */
030public abstract class ProviderActivator implements BundleActivator {
031    
032    public static final String API_VERSION = "APIVersion";
033
034    private final Provider provider;
035    private ServiceRegistration<Provider> providerRegistration = null;
036
037    protected ProviderActivator(final Provider provider) {
038        this.provider = provider;
039    }
040
041    @Override
042    public void start(final BundleContext context) throws Exception {
043        final Hashtable<String, String> props = new Hashtable<>();
044        props.put(API_VERSION, provider.getVersions());
045        providerRegistration = context.registerService(Provider.class, provider, props);
046    }
047
048    @Override
049    public void stop(BundleContext context) throws Exception {
050        if (providerRegistration != null) {
051            providerRegistration.unregister();
052        }
053    }
054
055}