1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.configuration2.interpol; 18 19 import org.apache.commons.text.lookup.StringLookupFactory; 20 21 /** 22 * <p> 23 * A specialized implementation of the {@code Lookup} interface that allows access to system properties. 24 * </p> 25 * <p> 26 * This implementation relies on {@code StrLookup.systemPropertiesLookup()} from the Commons Lang project to resolve 27 * system properties. It can be used for referencing system properties in configuration files in an easy way, for 28 * instance: 29 * </p> 30 * 31 * <pre> 32 * current.user = ${sys:user.name} 33 * </pre> 34 * 35 * <p> 36 * {@code SystemPropertiesLookup} is one of the standard lookups that is registered per default for each configuration. 37 * </p> 38 * 39 * @since 2.0 40 * @deprecated Use {@link DefaultLookups#SYSTEM_PROPERTIES}. 41 */ 42 @Deprecated 43 public class SystemPropertiesLookup implements Lookup { 44 @Override 45 public Object lookup(final String variable) { 46 return StringLookupFactory.INSTANCE.systemPropertyStringLookup().lookup(variable); 47 } 48 }