001/*
002 * Copyright 2012-2018 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 *      http://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.boot.context.properties.bind;
018
019import org.springframework.core.env.PropertyResolver;
020
021/**
022 * Optional strategy that used by a {@link Binder} to resolve property placeholders.
023 *
024 * @author Phillip Webb
025 * @author Madhura Bhave
026 * @since 2.0.0
027 * @see PropertySourcesPlaceholdersResolver
028 */
029@FunctionalInterface
030public interface PlaceholdersResolver {
031
032        /**
033         * No-op {@link PropertyResolver}.
034         */
035        PlaceholdersResolver NONE = (value) -> value;
036
037        /**
038         * Called to resolve any placeholders in the given value.
039         * @param value the source value
040         * @return a value with placeholders resolved
041         */
042        Object resolvePlaceholders(Object value);
043
044}