| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.commons.configuration2.interpol; |
| |
| import org.apache.commons.lang3.text.StrLookup; |
| |
| /** |
| * <p> |
| * A specialized implementation of the {@code Lookup} interface that allows |
| * access to system properties. |
| * </p> |
| * <p> |
| * This implementation relies on {@code StrLookup.systemPropertiesLookup()} from |
| * the Commons Lang project to resolve system properties. It can be used for |
| * referencing system properties in configuration files in an easy way, for |
| * instance: |
| * </p> |
| * |
| * <pre> |
| * current.user = ${sys:user.name} |
| * </pre> |
| * |
| * <p> |
| * {@code SystemPropertiesLookup} is one of the standard lookups that is |
| * registered per default for each configuration. |
| * </p> |
| * |
| * @version $Id$ |
| * @since 2.0 |
| */ |
| public class SystemPropertiesLookup implements Lookup |
| { |
| /** The underlying StrLookup object. */ |
| private final StrLookup<String> sysLookup = StrLookup |
| .systemPropertiesLookup(); |
| |
| @Override |
| public Object lookup(String variable) |
| { |
| return sysLookup.lookup(variable); |
| } |
| } |