org.springframework.boot.context.properties.source.ConfigurationPropertySource Maven / Gradle / Ivy
/*
* 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;
/**
* 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 {@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
* {@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 {@link Predicate}.
* @param filter the filter to match
* @return a filtered {@link ConfigurationPropertySource} instance
*/
default ConfigurationPropertySource filter(Predicate filter) {
return new FilteredConfigurationPropertiesSource(this, filter);
}
/**
* 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.
* @return the underlying property source or {@code null}.
*/
default Object getUnderlyingSource() {
return null;
}
}