org.springframework.beans.factory.annotation.InjectionMetadata Maven / Gradle / Ivy
/*
* Copyright 2002-2018 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
*
* 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.beans.factory.annotation;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.LinkedHashSet;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.MutablePropertyValues;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.lang.Nullable;
import org.springframework.util.ReflectionUtils;
/**
* Internal class for managing injection metadata.
* Not intended for direct use in applications.
*
* Used by {@link AutowiredAnnotationBeanPostProcessor},
* {@link org.springframework.context.annotation.CommonAnnotationBeanPostProcessor} and
* {@link org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor}.
*
* @author Juergen Hoeller
* @since 2.5
*/
public class InjectionMetadata {
private static final Log logger = LogFactory.getLog(InjectionMetadata.class);
private final Class targetClass;
private final Collection injectedElements;
@Nullable
private volatile Set checkedElements;
public InjectionMetadata(Class targetClass, Collection elements) {
this.targetClass = targetClass;
this.injectedElements = elements;
}
public void checkConfigMembers(RootBeanDefinition beanDefinition) {
Set checkedElements = new LinkedHashSet<>(this.injectedElements.size());
for (InjectedElement element : this.injectedElements) {
Member member = element.getMember();
if (!beanDefinition.isExternallyManagedConfigMember(member)) {
beanDefinition.registerExternallyManagedConfigMember(member);
checkedElements.add(element);
if (logger.isTraceEnabled()) {
logger.trace("Registered injected element on class [" + this.targetClass.getName() + "]: " + element);
}
}
}
this.checkedElements = checkedElements;
}
public void inject(Object target, @Nullable String beanName, @Nullable PropertyValues pvs) throws Throwable {
Collection checkedElements = this.checkedElements;
Collection elementsToIterate =
(checkedElements != null ? checkedElements : this.injectedElements);
if (!elementsToIterate.isEmpty()) {
for (InjectedElement element : elementsToIterate) {
if (logger.isTraceEnabled()) {
logger.trace("Processing injected element of bean '" + beanName + "': " + element);
}
element.inject(target, beanName, pvs);
}
}
}
/**
* Clear property skipping for the contained elements.
* @since 3.2.13
*/
public void clear(@Nullable PropertyValues pvs) {
Collection checkedElements = this.checkedElements;
Collection elementsToIterate =
(checkedElements != null ? checkedElements : this.injectedElements);
if (!elementsToIterate.isEmpty()) {
for (InjectedElement element : elementsToIterate) {
element.clearPropertySkipping(pvs);
}
}
}
public static boolean needsRefresh(@Nullable InjectionMetadata metadata, Class clazz) {
return (metadata == null || metadata.targetClass != clazz);
}
/**
* A single injected element.
*/
public abstract static class InjectedElement {
protected final Member member;
protected final boolean isField;
@Nullable
protected final PropertyDescriptor pd;
@Nullable
protected volatile Boolean skip;
protected InjectedElement(Member member, @Nullable PropertyDescriptor pd) {
this.member = member;
this.isField = (member instanceof Field);
this.pd = pd;
}
public final Member getMember() {
return this.member;
}
protected final Class getResourceType() {
if (this.isField) {
return ((Field) this.member).getType();
}
else if (this.pd != null) {
return this.pd.getPropertyType();
}
else {
return ((Method) this.member).getParameterTypes()[0];
}
}
protected final void checkResourceType(Class resourceType) {
if (this.isField) {
Class fieldType = ((Field) this.member).getType();
if (!(resourceType.isAssignableFrom(fieldType) || fieldType.isAssignableFrom(resourceType))) {
throw new IllegalStateException("Specified field type [" + fieldType +
"] is incompatible with resource type [" + resourceType.getName() + "]");
}
}
else {
Class paramType =
(this.pd != null ? this.pd.getPropertyType() : ((Method) this.member).getParameterTypes()[0]);
if (!(resourceType.isAssignableFrom(paramType) || paramType.isAssignableFrom(resourceType))) {
throw new IllegalStateException("Specified parameter type [" + paramType +
"] is incompatible with resource type [" + resourceType.getName() + "]");
}
}
}
/**
* Either this or {@link #getResourceToInject} needs to be overridden.
*/
protected void inject(Object target, @Nullable String requestingBeanName, @Nullable PropertyValues pvs)
throws Throwable {
if (this.isField) {
Field field = (Field) this.member;
ReflectionUtils.makeAccessible(field);
field.set(target, getResourceToInject(target, requestingBeanName));
}
else {
if (checkPropertySkipping(pvs)) {
return;
}
try {
Method method = (Method) this.member;
ReflectionUtils.makeAccessible(method);
method.invoke(target, getResourceToInject(target, requestingBeanName));
}
catch (InvocationTargetException ex) {
throw ex.getTargetException();
}
}
}
/**
* Check whether this injector's property needs to be skipped due to
* an explicit property value having been specified. Also marks the
* affected property as processed for other processors to ignore it.
*/
protected boolean checkPropertySkipping(@Nullable PropertyValues pvs) {
Boolean skip = this.skip;
if (skip != null) {
return skip;
}
if (pvs == null) {
this.skip = false;
return false;
}
synchronized (pvs) {
skip = this.skip;
if (skip != null) {
return skip;
}
if (this.pd != null) {
if (pvs.contains(this.pd.getName())) {
// Explicit value provided as part of the bean definition.
this.skip = true;
return true;
}
else if (pvs instanceof MutablePropertyValues) {
((MutablePropertyValues) pvs).registerProcessedProperty(this.pd.getName());
}
}
this.skip = false;
return false;
}
}
/**
* Clear property skipping for this element.
* @since 3.2.13
*/
protected void clearPropertySkipping(@Nullable PropertyValues pvs) {
if (pvs == null) {
return;
}
synchronized (pvs) {
if (Boolean.FALSE.equals(this.skip) && this.pd != null && pvs instanceof MutablePropertyValues) {
((MutablePropertyValues) pvs).clearProcessedProperty(this.pd.getName());
}
}
}
/**
* Either this or {@link #inject} needs to be overridden.
*/
@Nullable
protected Object getResourceToInject(Object target, @Nullable String requestingBeanName) {
return null;
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (!(other instanceof InjectedElement)) {
return false;
}
InjectedElement otherElement = (InjectedElement) other;
return this.member.equals(otherElement.member);
}
@Override
public int hashCode() {
return this.member.getClass().hashCode() * 29 + this.member.getName().hashCode();
}
@Override
public String toString() {
return getClass().getSimpleName() + " for " + this.member;
}
}
}