001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *      http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.oozie.util;
019
020import org.apache.hadoop.conf.Configuration;
021
022/**
023 *
024 */
025public class ConfigUtils {
026    private final static XLog LOG = XLog.getLog(ConfigUtils.class);
027
028    /**
029     * Fetches a property using both a deprecated name and the new name. The deprecated property
030     * has precedence over the new name. If the deprecated name is used a warning is written to
031     * the log.
032     *
033     * @param conf configuration object.
034     * @param newName new property name.
035     * @param oldName deprecated property name.
036     * @param defaultValue default value.
037     * @return the property value, or the default value if not found under the deprecated name and the new name.
038     */
039    public static String getWithDeprecatedCheck(Configuration conf, String newName, String oldName,
040                                                String defaultValue) {
041        String value = conf.get(oldName, null);
042        if (value == null) {
043            value = conf.get(newName, defaultValue);
044        }
045        else {
046            LOG.warn("Using a deprecated configuration property [{0}], should use [{1}].  " +
047                     "Please delete the deprecated property in order for the new property to take effect.",
048                     oldName, newName);
049        }
050        return value;
051    }
052
053    /**
054     * Fetches a property using both a deprecated name and the new name. The deprecated property
055     * has precedence over the new name. If the deprecated name is used a warning is written to
056     * the log.
057     *
058     * @param conf configuration object.
059     * @param newName new property name.
060     * @param oldName deprecated property name.
061     * @param defaultValue default value.
062     * @return the property value, or the default value if not found under the deprecated name and the new name.
063     */
064    public static boolean getWithDeprecatedCheck(Configuration conf, String newName, String oldName,
065                                                 boolean defaultValue) {
066        String value = getWithDeprecatedCheck(conf, newName, oldName, Boolean.toString(defaultValue));
067        return Boolean.parseBoolean(value);
068    }
069}