org.springframework.boot.context.properties.source.ConfigurationPropertySources Maven / Gradle / Ivy
/*
* Copyright 2012-2018 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.Collections;
import java.util.stream.Stream;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.Environment;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import org.springframework.core.env.PropertySource.StubPropertySource;
import org.springframework.core.env.PropertySources;
import org.springframework.core.env.PropertySourcesPropertyResolver;
import org.springframework.util.Assert;
/**
* Provides access to {@link ConfigurationPropertySource ConfigurationPropertySources}.
*
* @author Phillip Webb
* @since 2.0.0
*/
public final class ConfigurationPropertySources {
/**
* The name of the {@link PropertySource} {@link #adapt adapter}.
*/
private static final String ATTACHED_PROPERTY_SOURCE_NAME = "configurationProperties";
private ConfigurationPropertySources() {
}
/**
* Determines if the specific {@link PropertySource} is the
* {@link ConfigurationPropertySource} that was {@link #attach(Environment) attached}
* to the {@link Environment}.
* @param propertySource the property source to test
* @return {@code true} if this is the attached {@link ConfigurationPropertySource}
*/
public static boolean isAttachedConfigurationPropertySource(
PropertySource propertySource) {
return ATTACHED_PROPERTY_SOURCE_NAME.equals(propertySource.getName());
}
/**
* Attach a {@link ConfigurationPropertySource} support to the specified
* {@link Environment}. Adapts each {@link PropertySource} managed by the environment
* to a {@link ConfigurationPropertySource} and allows classic
* {@link PropertySourcesPropertyResolver} calls to resolve using
* {@link ConfigurationPropertyName configuration property names}.
*
* The attached resolver will dynamically track any additions or removals from the
* underlying {@link Environment} property sources.
* @param environment the source environment (must be an instance of
* {@link ConfigurableEnvironment})
* @see #get(Environment)
*/
public static void attach(Environment environment) {
Assert.isInstanceOf(ConfigurableEnvironment.class, environment);
MutablePropertySources sources = ((ConfigurableEnvironment) environment)
.getPropertySources();
PropertySource attached = sources.get(ATTACHED_PROPERTY_SOURCE_NAME);
if (attached != null && attached.getSource() != sources) {
sources.remove(ATTACHED_PROPERTY_SOURCE_NAME);
attached = null;
}
if (attached == null) {
sources.addFirst(new ConfigurationPropertySourcesPropertySource(
ATTACHED_PROPERTY_SOURCE_NAME,
new SpringConfigurationPropertySources(sources)));
}
}
/**
* Return a set of {@link ConfigurationPropertySource} instances that have previously
* been {@link #attach(Environment) attached} to the {@link Environment}.
* @param environment the source environment (must be an instance of
* {@link ConfigurableEnvironment})
* @return an iterable set of configuration property sources
* @throws IllegalStateException if not configuration property sources have been
* attached
*/
public static Iterable get(Environment environment) {
Assert.isInstanceOf(ConfigurableEnvironment.class, environment);
MutablePropertySources sources = ((ConfigurableEnvironment) environment)
.getPropertySources();
ConfigurationPropertySourcesPropertySource attached = (ConfigurationPropertySourcesPropertySource) sources
.get(ATTACHED_PROPERTY_SOURCE_NAME);
if (attached == null) {
return from(sources);
}
return attached.getSource();
}
/**
* Return {@link Iterable} containing a single new {@link ConfigurationPropertySource}
* adapted from the given Spring {@link PropertySource}.
* @param source the Spring property source to adapt
* @return an {@link Iterable} containing a single newly adapted
* {@link SpringConfigurationPropertySource}
*/
public static Iterable from(PropertySource source) {
return Collections.singleton(SpringConfigurationPropertySource.from(source));
}
/**
* Return {@link Iterable} containing new {@link ConfigurationPropertySource}
* instances adapted from the given Spring {@link PropertySource PropertySources}.
*
* This method will flatten any nested property sources and will filter all
* {@link StubPropertySource stub property sources}. Updates to the underlying source,
* identified by changes in the sources returned by its iterator, will be
* automatically tracked. The underlying source should be thread safe, for example a
* {@link MutablePropertySources}
* @param sources the Spring property sources to adapt
* @return an {@link Iterable} containing newly adapted
* {@link SpringConfigurationPropertySource} instances
*/
public static Iterable from(
Iterable> sources) {
return new SpringConfigurationPropertySources(sources);
}
private static Stream> streamPropertySources(
PropertySources sources) {
return sources.stream().flatMap(ConfigurationPropertySources::flatten)
.filter(ConfigurationPropertySources::isIncluded);
}
private static Stream> flatten(PropertySource source) {
if (source.getSource() instanceof ConfigurableEnvironment) {
return streamPropertySources(
((ConfigurableEnvironment) source.getSource()).getPropertySources());
}
return Stream.of(source);
}
private static boolean isIncluded(PropertySource source) {
return !(source instanceof StubPropertySource)
&& !(source instanceof ConfigurationPropertySourcesPropertySource);
}
}