org.springframework.boot.context.properties.ConfigurationPropertiesBindConstructorProvider 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;
import java.lang.reflect.Constructor;
import org.springframework.beans.BeanUtils;
import org.springframework.boot.context.properties.bind.BindConstructorProvider;
import org.springframework.boot.context.properties.bind.Bindable;
import org.springframework.core.KotlinDetector;
import org.springframework.core.annotation.MergedAnnotations;
import org.springframework.util.Assert;
/**
* {@link BindConstructorProvider} used when binding
* {@link ConfigurationProperties @ConfigurationProperties}.
*
* @author Madhura Bhave
* @author Phillip Webb
*/
class ConfigurationPropertiesBindConstructorProvider implements BindConstructorProvider {
static final ConfigurationPropertiesBindConstructorProvider INSTANCE = new ConfigurationPropertiesBindConstructorProvider();
@Override
public Constructor getBindConstructor(Bindable bindable, boolean isNestedConstructorBinding) {
return getBindConstructor(bindable.getType().resolve(), isNestedConstructorBinding);
}
Constructor getBindConstructor(Class type, boolean isNestedConstructorBinding) {
if (type == null) {
return null;
}
Constructor constructor = findConstructorBindingAnnotatedConstructor(type);
if (constructor == null && (isConstructorBindingAnnotatedType(type) || isNestedConstructorBinding)) {
constructor = deduceBindConstructor(type);
}
return constructor;
}
private Constructor findConstructorBindingAnnotatedConstructor(Class type) {
if (isKotlinType(type)) {
Constructor constructor = BeanUtils.findPrimaryConstructor(type);
if (constructor != null) {
return findAnnotatedConstructor(type, constructor);
}
}
return findAnnotatedConstructor(type, type.getDeclaredConstructors());
}
private Constructor findAnnotatedConstructor(Class type, Constructor... candidates) {
Constructor constructor = null;
for (Constructor candidate : candidates) {
if (MergedAnnotations.from(candidate).isPresent(ConstructorBinding.class)) {
Assert.state(candidate.getParameterCount() > 0,
type.getName() + " declares @ConstructorBinding on a no-args constructor");
Assert.state(constructor == null,
type.getName() + " has more than one @ConstructorBinding constructor");
constructor = candidate;
}
}
return constructor;
}
private boolean isConstructorBindingAnnotatedType(Class type) {
return MergedAnnotations.from(type, MergedAnnotations.SearchStrategy.TYPE_HIERARCHY_AND_ENCLOSING_CLASSES)
.isPresent(ConstructorBinding.class);
}
private Constructor deduceBindConstructor(Class type) {
if (isKotlinType(type)) {
return deducedKotlinBindConstructor(type);
}
Constructor[] constructors = type.getDeclaredConstructors();
if (constructors.length == 1 && constructors[0].getParameterCount() > 0) {
return constructors[0];
}
return null;
}
private Constructor deducedKotlinBindConstructor(Class type) {
Constructor primaryConstructor = BeanUtils.findPrimaryConstructor(type);
if (primaryConstructor != null && primaryConstructor.getParameterCount() > 0) {
return primaryConstructor;
}
return null;
}
private boolean isKotlinType(Class type) {
return KotlinDetector.isKotlinPresent() && KotlinDetector.isKotlinType(type);
}
}