/*
* Copyright 2012-2017 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
*
* http://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.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.core.env.PropertySource;
import org.springframework.core.env.PropertySource.StubPropertySource;
import org.springframework.util.Assert;
import org.springframework.util.ObjectUtils;
/**
* Adapter to convert Spring's {@link MutablePropertySources} to
* {@link ConfigurationPropertySource ConfigurationPropertySources}.
*
* @author Phillip Webb
*/
class SpringConfigurationPropertySources
implements Iterable<ConfigurationPropertySource> {
private final MutablePropertySources sources;
private volatile PropertySourcesKey lastKey;
private volatile List<ConfigurationPropertySource> adaptedSources;
SpringConfigurationPropertySources(MutablePropertySources sources) {
Assert.notNull(sources, "Sources must not be null");
this.sources = sources;
}
@Override
public Iterator<ConfigurationPropertySource> iterator() {
checkForChanges();
return this.adaptedSources.iterator();
}
private void checkForChanges() {
PropertySourcesKey lastKey = this.lastKey;
PropertySourcesKey currentKey = new PropertySourcesKey(this.sources);
if (!currentKey.equals(lastKey)) {
onChange(this.sources);
this.lastKey = currentKey;
}
}
private void onChange(MutablePropertySources sources) {
this.adaptedSources = streamPropertySources(sources)
.map(SpringConfigurationPropertySource::from)
.collect(Collectors.toList());
}
private Stream<PropertySource<?>> streamPropertySources(
Iterable<PropertySource<?>> sources) {
return StreamSupport.stream(sources.spliterator(), false).flatMap(this::flatten)
.filter(this::isIncluded);
}
private Stream<PropertySource<?>> flatten(PropertySource<?> source) {
if (source.getSource() instanceof ConfigurableEnvironment) {
return streamPropertySources(
((ConfigurableEnvironment) source.getSource()).getPropertySources());
}
return Stream.of(source);
}
private boolean isIncluded(PropertySource<?> source) {
return !(source instanceof StubPropertySource)
&& !(source instanceof ConfigurationPropertySourcesPropertySource);
}
private static class PropertySourcesKey {
private final List<PropertySourceKey> keys = new ArrayList<>();
PropertySourcesKey(MutablePropertySources sources) {
sources.forEach(this::addKey);
}
private void addKey(PropertySource<?> source) {
this.keys.add(new PropertySourceKey(source));
}
@Override
public int hashCode() {
return this.keys.hashCode();
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
return this.keys.equals(((PropertySourcesKey) obj).keys);
}
}
private static class PropertySourceKey {
private final String name;
private final Class<?> type;
PropertySourceKey(PropertySource<?> source) {
this.name = source.getName();
this.type = source.getClass();
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ObjectUtils.nullSafeHashCode(this.name);
result = prime * result + ObjectUtils.nullSafeHashCode(this.type);
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null || getClass() != obj.getClass()) {
return false;
}
PropertySourceKey other = (PropertySourceKey) obj;
boolean result = true;
result = result && ObjectUtils.nullSafeEquals(this.name, other.name);
result = result && ObjectUtils.nullSafeEquals(this.type, other.type);
return result;
}
}
}