/*
* 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.annotation;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.ImportSelector;
import org.springframework.core.OrderComparator;
import org.springframework.core.Ordered;
import org.springframework.test.context.junit4.SpringRunner;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
A set of @Configuration
classes that can be registered in ApplicationContext
. Classes can be returned from one or more Configurations
instances by using getClasses(Configurations[])
. The resulting array follows the ordering rules usually applied by the ApplicationContext
and/or custom ImportSelector
implementations. This class is primarily intended for use with tests that need to specify configuration classes but can't use SpringRunner
.
Implementations of this class should be annotated with @Order
or implement Ordered
.
Author: Phillip Webb See Also: Since: 2.0.0
/**
* A set of {@link Configuration @Configuration} classes that can be registered in
* {@link ApplicationContext}. Classes can be returned from one or more
* {@link Configurations} instances by using {@link #getClasses(Configurations[])}. The
* resulting array follows the ordering rules usually applied by the
* {@link ApplicationContext} and/or custom {@link ImportSelector} implementations.
* <p>
* This class is primarily intended for use with tests that need to specify configuration
* classes but can't use {@link SpringRunner}.
* <p>
* Implementations of this class should be annotated with {@code @Order} or implement
* {@link Ordered}.
*
* @author Phillip Webb
* @since 2.0.0
* @see UserConfigurations
*/
public abstract class Configurations {
private static final Comparator<Object> COMPARATOR = OrderComparator.INSTANCE
.thenComparing((other) -> other.getClass().getName());
private final Set<Class<?>> classes;
protected Configurations(Collection<Class<?>> classes) {
Assert.notNull(classes, "Classes must not be null");
Collection<Class<?>> sorted = sort(classes);
this.classes = Collections.unmodifiableSet(new LinkedHashSet<>(sorted));
}
Sort configuration classes into the order that they should be applied.
Params: - classes – the classes to sort
Returns: a sorted set of classes
/**
* Sort configuration classes into the order that they should be applied.
* @param classes the classes to sort
* @return a sorted set of classes
*/
protected Collection<Class<?>> sort(Collection<Class<?>> classes) {
return classes;
}
protected final Set<Class<?>> getClasses() {
return this.classes;
}
Merge configurations from another source of the same type.
Params: - other – the other
Configurations
(must be of the same type as this instance)
Returns: a new configurations instance (must be of the same type as this instance)
/**
* Merge configurations from another source of the same type.
* @param other the other {@link Configurations} (must be of the same type as this
* instance)
* @return a new configurations instance (must be of the same type as this instance)
*/
protected Configurations merge(Configurations other) {
Set<Class<?>> mergedClasses = new LinkedHashSet<>(getClasses());
mergedClasses.addAll(other.getClasses());
return merge(mergedClasses);
}
Merge configurations.
Params: - mergedClasses – the merged classes
Returns: a new configurations instance (must be of the same type as this instance)
/**
* Merge configurations.
* @param mergedClasses the merged classes
* @return a new configurations instance (must be of the same type as this instance)
*/
protected abstract Configurations merge(Set<Class<?>> mergedClasses);
Return the classes from all the specified configurations in the order that they
would be registered.
Params: - configurations – the source configuration
Returns: configuration classes in registration order
/**
* Return the classes from all the specified configurations in the order that they
* would be registered.
* @param configurations the source configuration
* @return configuration classes in registration order
*/
public static Class<?>[] getClasses(Configurations... configurations) {
return getClasses(Arrays.asList(configurations));
}
Return the classes from all the specified configurations in the order that they
would be registered.
Params: - configurations – the source configuration
Returns: configuration classes in registration order
/**
* Return the classes from all the specified configurations in the order that they
* would be registered.
* @param configurations the source configuration
* @return configuration classes in registration order
*/
public static Class<?>[] getClasses(Collection<Configurations> configurations) {
List<Configurations> ordered = new ArrayList<>(configurations);
ordered.sort(COMPARATOR);
List<Configurations> collated = collate(ordered);
LinkedHashSet<Class<?>> classes = collated.stream().flatMap(Configurations::streamClasses)
.collect(Collectors.toCollection(LinkedHashSet::new));
return ClassUtils.toClassArray(classes);
}
private static Stream<Class<?>> streamClasses(Configurations configurations) {
return configurations.getClasses().stream();
}
private static List<Configurations> collate(List<Configurations> orderedConfigurations) {
LinkedList<Configurations> collated = new LinkedList<>();
for (Configurations item : orderedConfigurations) {
if (collated.isEmpty() || collated.getLast().getClass() != item.getClass()) {
collated.add(item);
}
else {
collated.set(collated.size() - 1, collated.getLast().merge(item));
}
}
return collated;
}
}