org.springframework.boot.context.properties.EnableConfigurationPropertiesImportSelector 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;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.GenericBeanDefinition;
import org.springframework.context.annotation.ImportBeanDefinitionRegistrar;
import org.springframework.context.annotation.ImportSelector;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.util.Assert;
import org.springframework.util.MultiValueMap;
import org.springframework.util.StringUtils;
/**
* Import selector that sets up binding of external properties to configuration classes
* (see {@link ConfigurationProperties}). It either registers a
* {@link ConfigurationProperties} bean or not, depending on whether the enclosing
* {@link EnableConfigurationProperties} explicitly declares one. If none is declared then
* a bean post processor will still kick in for any beans annotated as external
* configuration. If one is declared, then a bean definition is registered with id equal
* to the class name (thus an application context usually only contains one
* {@link ConfigurationProperties} bean of each unique type).
*
* @author Dave Syer
* @author Christian Dupuis
* @author Stephane Nicoll
*/
class EnableConfigurationPropertiesImportSelector implements ImportSelector {
private static final String[] IMPORTS = {
ConfigurationPropertiesBeanRegistrar.class.getName(),
ConfigurationPropertiesBindingPostProcessorRegistrar.class.getName() };
@Override
public String[] selectImports(AnnotationMetadata metadata) {
return IMPORTS;
}
/**
* {@link ImportBeanDefinitionRegistrar} for configuration properties support.
*/
public static class ConfigurationPropertiesBeanRegistrar
implements ImportBeanDefinitionRegistrar {
@Override
public void registerBeanDefinitions(AnnotationMetadata metadata,
BeanDefinitionRegistry registry) {
getTypes(metadata).forEach((type) -> register(registry,
(ConfigurableListableBeanFactory) registry, type));
}
private List> getTypes(AnnotationMetadata metadata) {
MultiValueMap attributes = metadata
.getAllAnnotationAttributes(
EnableConfigurationProperties.class.getName(), false);
return collectClasses((attributes != null) ? attributes.get("value")
: Collections.emptyList());
}
private List> collectClasses(List values) {
return values.stream().flatMap((value) -> Arrays.stream((Object[]) value))
.map((o) -> (Class) o).filter((type) -> void.class != type)
.collect(Collectors.toList());
}
private void register(BeanDefinitionRegistry registry,
ConfigurableListableBeanFactory beanFactory, Class type) {
String name = getName(type);
if (!containsBeanDefinition(beanFactory, name)) {
registerBeanDefinition(registry, name, type);
}
}
private String getName(Class type) {
ConfigurationProperties annotation = AnnotationUtils.findAnnotation(type,
ConfigurationProperties.class);
String prefix = (annotation != null) ? annotation.prefix() : "";
return (StringUtils.hasText(prefix) ? prefix + "-" + type.getName()
: type.getName());
}
private boolean containsBeanDefinition(
ConfigurableListableBeanFactory beanFactory, String name) {
if (beanFactory.containsBeanDefinition(name)) {
return true;
}
BeanFactory parent = beanFactory.getParentBeanFactory();
if (parent instanceof ConfigurableListableBeanFactory) {
return containsBeanDefinition((ConfigurableListableBeanFactory) parent,
name);
}
return false;
}
private void registerBeanDefinition(BeanDefinitionRegistry registry, String name,
Class type) {
assertHasAnnotation(type);
GenericBeanDefinition definition = new GenericBeanDefinition();
definition.setBeanClass(type);
registry.registerBeanDefinition(name, definition);
}
private void assertHasAnnotation(Class type) {
Assert.notNull(
AnnotationUtils.findAnnotation(type, ConfigurationProperties.class),
() -> "No " + ConfigurationProperties.class.getSimpleName()
+ " annotation found on '" + type.getName() + "'.");
}
}
}