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 */
017package org.apache.juneau.config;
018
019import static org.apache.juneau.commons.utils.Shorts.*;
020
021import org.apache.juneau.commons.settings.*;
022
023/**
024 * {@link PropertySource} adapter for {@link Config}.
025 */
026public class ConfigPropertySource implements PropertySource {
027
028   private final Config config;
029
030   /**
031    * Constructor.
032    *
033    * @param config
034    *    The wrapped config.
035    *    <br>Can be <jk>null</jk> (all lookups return {@link PropertyLookupResult#missing()}).
036    */
037   public ConfigPropertySource(Config config) {
038      this.config = config;
039   }
040
041   @Override
042   public PropertyLookupResult get(String name) {
043      if (config == null)
044         return PropertyLookupResult.missing();
045      try {
046         var value = config.getString(name);
047         return value == null ? PropertyLookupResult.missing() : PropertyLookupResult.present(o(value));
048      } catch (@SuppressWarnings("unused") Exception unused) {
049         // A lookup failure (bad key, unreadable config) is treated as an absent property so the property-source chain can fall through to the next source.
050         return PropertyLookupResult.missing();
051      }
052   }
053}