/*
 * Copyright 2012-2019 the original author or authors.
 *
 * Licensed 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
 *
 *      https://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.springframework.boot.context.properties.source;

import java.util.function.Predicate;

import org.springframework.boot.origin.OriginTrackedValue;

Author:Phillip Webb, Madhura Bhave
See Also:
Since:2.0.0
/** * A source of {@link ConfigurationProperty ConfigurationProperties}. * * @author Phillip Webb * @author Madhura Bhave * @since 2.0.0 * @see ConfigurationPropertyName * @see OriginTrackedValue * @see #getConfigurationProperty(ConfigurationPropertyName) */
@FunctionalInterface public interface ConfigurationPropertySource {
Return a single ConfigurationProperty from the source or null if no property can be found.
Params:
  • name – the name of the property (must not be null)
Returns:the associated object or null.
/** * Return a single {@link ConfigurationProperty} from the source or {@code null} if no * property can be found. * @param name the name of the property (must not be {@code null}) * @return the associated object or {@code null}. */
ConfigurationProperty getConfigurationProperty(ConfigurationPropertyName name);
Returns if the source contains any descendants of the specified name. May return ConfigurationPropertyState.PRESENT or ConfigurationPropertyState.ABSENT if an answer can be determined or ConfigurationPropertyState.UNKNOWN if it's not possible to determine a definitive answer.
Params:
  • name – the name to check
Returns:if the source contains any descendants
/** * Returns if the source contains any descendants of the specified name. May return * {@link ConfigurationPropertyState#PRESENT} or * {@link ConfigurationPropertyState#ABSENT} if an answer can be determined or * {@link ConfigurationPropertyState#UNKNOWN} if it's not possible to determine a * definitive answer. * @param name the name to check * @return if the source contains any descendants */
default ConfigurationPropertyState containsDescendantOf(ConfigurationPropertyName name) { return ConfigurationPropertyState.UNKNOWN; }
Return a filtered variant of this source, containing only names that match the given Predicate.
Params:
  • filter – the filter to match
Returns:a filtered ConfigurationPropertySource instance
/** * Return a filtered variant of this source, containing only names that match the * given {@link Predicate}. * @param filter the filter to match * @return a filtered {@link ConfigurationPropertySource} instance */
default ConfigurationPropertySource filter(Predicate<ConfigurationPropertyName> filter) { return new FilteredConfigurationPropertiesSource(this, filter); }
Return a variant of this source that supports name aliases.
Params:
  • aliases – a function that returns a stream of aliases for any given name
Returns:a ConfigurationPropertySource instance supporting name aliases
/** * Return a variant of this source that supports name aliases. * @param aliases a function that returns a stream of aliases for any given name * @return a {@link ConfigurationPropertySource} instance supporting name aliases */
default ConfigurationPropertySource withAliases(ConfigurationPropertyNameAliases aliases) { return new AliasedConfigurationPropertySource(this, aliases); }
Return the underlying source that is actually providing the properties.
Returns:the underlying property source or null.
/** * Return the underlying source that is actually providing the properties. * @return the underlying property source or {@code null}. */
default Object getUnderlyingSource() { return null; } }