EnvironmentLookup.java
- /*
- * 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;
- /**
- * <p>
- * A specialized lookup implementation that allows access to environment variables.
- * </p>
- * <p>
- * This implementation relies on {@link System#getenv()} to resolve environment variables. It can be used for
- * referencing environment variables in configuration files in an easy way, for instance:
- * </p>
- *
- * <pre>
- * java.home = ${env:JAVA_HOME}
- * </pre>
- *
- * <p>
- * {@code EnvironmentLookup} is one of the standard lookups that is registered per default for each configuration.
- * </p>
- *
- * @since 1.7
- * @deprecated Use {@link DefaultLookups#ENVIRONMENT}.
- */
- @Deprecated
- public class EnvironmentLookup implements Lookup {
- /**
- * Performs a lookup for the specified variable. This implementation directly delegates to a {@code System.getenv()}.
- *
- * @param key the key to lookup
- * @return the value of this key or <strong>null</strong> if it cannot be resolved
- */
- @Override
- public String lookup(final String key) {
- return System.getenv(key);
- }
- }