001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.test.annotation;
018
019import org.springframework.lang.Nullable;
020
021/**
022 * <p>
023 * Strategy interface for retrieving <em>profile values</em> for a given
024 * testing environment.
025 * </p>
026 * <p>
027 * Concrete implementations must provide a {@code public} no-args
028 * constructor.
029 * </p>
030 * <p>
031 * Spring provides the following out-of-the-box implementations:
032 * </p>
033 * <ul>
034 * <li>{@link SystemProfileValueSource}</li>
035 * </ul>
036 *
037 * @author Rod Johnson
038 * @author Sam Brannen
039 * @since 2.0
040 * @see ProfileValueSourceConfiguration
041 * @see IfProfileValue
042 * @see ProfileValueUtils
043 */
044public interface ProfileValueSource {
045
046        /**
047         * Get the <em>profile value</em> indicated by the specified key.
048         * @param key the name of the <em>profile value</em>
049         * @return the String value of the <em>profile value</em>, or {@code null}
050         * if there is no <em>profile value</em> with that key
051         */
052        @Nullable
053        String get(String key);
054
055}