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    package org.apache.logging.log4j.core.config;
018    
019    import java.util.HashMap;
020    import java.util.Map;
021    
022    import org.apache.logging.log4j.core.config.plugins.Plugin;
023    import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
024    import org.apache.logging.log4j.core.config.plugins.PluginElement;
025    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
026    import org.apache.logging.log4j.core.lookup.Interpolator;
027    import org.apache.logging.log4j.core.lookup.MapLookup;
028    import org.apache.logging.log4j.core.lookup.StrLookup;
029    
030    /**
031     * Handles properties defined in the configuration.
032     */
033    @Plugin(name = "properties", category = Node.CATEGORY, printObject = true)
034    public final class PropertiesPlugin {
035    
036        private PropertiesPlugin() {
037        }
038    
039        /**
040         * Create the Properties component.
041         * @param properties An array of Property elements.
042         * @param config The Configuration.
043         * @return An Interpolator that includes the configuration properties.
044         */
045        @PluginFactory
046        public static StrLookup configureSubstitutor(@PluginElement("Properties") final Property[] properties,
047                                                     @PluginConfiguration final Configuration config) {
048            if (properties == null) {
049                return new Interpolator(config.getProperties());
050            }
051            final Map<String, String> map = new HashMap<String, String>(config.getProperties());
052    
053            for (final Property prop : properties) {
054                map.put(prop.getName(), prop.getValue());
055            }
056    
057            return new Interpolator(new MapLookup(map), config.getPluginPackages());
058        }
059    }