    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.lookup;
    018
    019    import java.util.MissingResourceException;
    020    import java.util.ResourceBundle;
    021
    022    import org.apache.logging.log4j.Logger;
    023    import org.apache.logging.log4j.Marker;
    024    import org.apache.logging.log4j.MarkerManager;
    025    import org.apache.logging.log4j.core.LogEvent;
    026    import org.apache.logging.log4j.core.config.plugins.Plugin;
    027    import org.apache.logging.log4j.status.StatusLogger;
    028
    029    /**
    030     * Looks up keys from resource bundles.
    031     */
    032    @Plugin(name = "bundle", category = StrLookup.CATEGORY)
    033    public class ResourceBundleLookup extends AbstractLookup {
    034
    035        private static final Logger LOGGER = StatusLogger.getLogger();
    036        private static final Marker LOOKUP = MarkerManager.getMarker("LOOKUP");
    037
    038        /**
    039         * Looks up the value for the key in the format "BundleName:BundleKey".
    040         *
    041         * For example: "com.domain.messages:MyKey".
    042         *
    043         * @param event
    044         *            The current LogEvent.
    045         * @param key
    046         *            the key to be looked up, may be null
    047         * @return The value associated with the key.
    048         */
    049        @Override
    050        public String lookup(final LogEvent event, final String key) {
    051            if (key == null) {
    052                return null;
    053            }
    054            final String[] keys = key.split(":");
    055            final int keyLen = keys.length;
    056            if (keyLen != 2) {
    057                LOGGER.warn(LOOKUP, "Bad ResourceBundle key format [{}]. Expected format is BundleName:KeyName.", key);
    058                return null;
    059            }
    060            final String bundleName = keys[0];
    061            final String bundleKey = keys[1];
    062            try {
    063                // The ResourceBundle class caches bundles, no need to cache here.
    064                return ResourceBundle.getBundle(bundleName).getString(bundleKey);
    065            } catch (final MissingResourceException e) {
    066                LOGGER.warn(LOOKUP, "Error looking up ResourceBundle [{}].", bundleName, e);
    067                return null;
    068            }
    069        }
    070    }