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.source;
018
019import java.util.Iterator;
020import java.util.function.Predicate;
021import java.util.stream.Stream;
022
023import org.springframework.boot.origin.OriginTrackedValue;
024
025/**
026 * A {@link ConfigurationPropertySource} with a fully {@link Iterable} set of entries.
027 * Implementations of this interface <strong>must</strong> be able to iterate over all
028 * contained configuration properties. Any {@code non-null} result from
029 * {@link #getConfigurationProperty(ConfigurationPropertyName)} must also have an
030 * equivalent entry in the {@link #iterator() iterator}.
031 *
032 * @author Phillip Webb
033 * @author Madhura Bhave
034 * @since 2.0.0
035 * @see ConfigurationPropertyName
036 * @see OriginTrackedValue
037 * @see #getConfigurationProperty(ConfigurationPropertyName)
038 * @see #iterator()
039 * @see #stream()
040 */
041public interface IterableConfigurationPropertySource
042                extends ConfigurationPropertySource, Iterable<ConfigurationPropertyName> {
043
044        /**
045         * Return an iterator for the {@link ConfigurationPropertyName names} managed by this
046         * source.
047         * @return an iterator (never {@code null})
048         */
049        @Override
050        default Iterator<ConfigurationPropertyName> iterator() {
051                return stream().iterator();
052        }
053
054        /**
055         * Returns a sequential {@code Stream} for the {@link ConfigurationPropertyName names}
056         * managed by this source.
057         * @return a stream of names (never {@code null})
058         */
059        Stream<ConfigurationPropertyName> stream();
060
061        @Override
062        default ConfigurationPropertyState containsDescendantOf(
063                        ConfigurationPropertyName name) {
064                return ConfigurationPropertyState.search(this, name::isAncestorOf);
065        }
066
067        @Override
068        default IterableConfigurationPropertySource filter(
069                        Predicate<ConfigurationPropertyName> filter) {
070                return new FilteredIterableConfigurationPropertiesSource(this, filter);
071        }
072
073        @Override
074        default IterableConfigurationPropertySource withAliases(
075                        ConfigurationPropertyNameAliases aliases) {
076                return new AliasedIterableConfigurationPropertySource(this, aliases);
077        }
078
079}