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本次继续介绍spring源码解析bean初始化、依赖注入的部分缓存
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上次介绍到这个方法app
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#doCreateBean这一行ide
// 今早的缓存单例对象以便循环引用
if (earlySingletonExposure) {
Object earlySingletonReference = getSingleton(beanName, false);
if (earlySingletonReference != null) {
if (exposedObject == bean) {
exposedObject = earlySingletonReference;
}
// 初始化的bean没被包装又有依赖
else if (!this.allowRawInjectionDespiteWrapping && hasDependentBean(beanName)) {
// 获取依赖的bean
String[] dependentBeans = getDependentBeans(beanName);
Set<String> actualDependentBeans = new LinkedHashSet<>(dependentBeans.length);
for (String dependentBean : dependentBeans) {
if (!removeSingletonIfCreatedForTypeCheckOnly(dependentBean)) {
actualDependentBeans.add(dependentBean);
}
}
if (!actualDependentBeans.isEmpty()) {
throw new BeanCurrentlyInCreationException(beanName,
"Bean with name '" + beanName + "' has been injected into other beans [" +
StringUtils.collectionToCommaDelimitedString(actualDependentBeans) +
"] in its raw version as part of a circular reference, but has eventually been " +
"wrapped. This means that said other beans do not use the final version of the " +
"bean. This is often the result of over-eager type matching - consider using " +
"'getBeanNamesOfType' with the 'allowEagerInit' flag turned off, for example.");
}
}
}
}
这一行ui
// Register bean as disposable.注册的bean做为可销毁的
try {
registerDisposableBeanIfNecessary(beanName, bean, mbd);
}
进入org.springframework.beans.factory.support.AbstractBeanFactory#registerDisposableBeanIfNecessary注册可销毁的beanthis
*/
protected void registerDisposableBeanIfNecessary(String beanName, Object bean, RootBeanDefinition mbd) {
AccessControlContext acc = (System.getSecurityManager() != null ? getAccessControlContext() : null);
// 不是原型模式，能够销毁
if (!mbd.isPrototype() && requiresDestruction(bean, mbd)) {
// 若是是单例
if (mbd.isSingleton()) {
// Register a DisposableBean implementation that performs all destruction
// work for the given bean: DestructionAwareBeanPostProcessors,
// DisposableBean interface, custom destroy method.
// 注册销毁的bean，这一部分在bean定义解析的部分介绍过，这里不做介绍了
registerDisposableBean(beanName,
new DisposableBeanAdapter(bean, beanName, mbd, getBeanPostProcessors(), acc));
}
else {
// A bean with a custom scope...
Scope scope = this.scopes.get(mbd.getScope());
if (scope == null) {
throw new IllegalStateException("No Scope registered for scope name '" + mbd.getScope() + "'");
}
// 销毁后的回调方法
scope.registerDestructionCallback(beanName,
new DisposableBeanAdapter(bean, beanName, mbd, getBeanPostProcessors(), acc));
}
}
}
返回org.springframework.beans.factory.support.AbstractBeanFactory#doGetBean这一行prototype
try {
// bean初始化
return createBean(beanName, mbd, args);
}
这里介绍完了，往下orm
// 发生异常销毁单例的bean destroySingleton(beanName);
进入
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry#destroySingleton
public void destroySingleton(String beanName) {
// Remove a registered singleton of the given name, if any.删除单例的bean，从本地缓存中删除
removeSingleton(beanName);
// Destroy the corresponding DisposableBean instance.
DisposableBean disposableBean;
synchronized (this.disposableBeans) {
// 从本地缓存中删除
disposableBean = (DisposableBean) this.disposableBeans.remove(beanName);
}
// bean销毁的逻辑
destroyBean(beanName, disposableBean);
}
这一行
从factoryBean中建立的bean对象 bean = getObjectForBeanInstance(sharedInstance, name, beanName, mbd);
这一行
else if (mbd.isPrototype()) {
// bean定义为原型模式
这一行
原型的bean建立以前维护内存中的缓存map映射信息 beforePrototypeCreation(beanName); // 原型的bean建立 prototypeInstance = createBean(beanName, mbd, args);
进入
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#createBean(java.lang.String, org.springframework.beans.factory.support.RootBeanDefinition, java.lang.Object[])这一行
// bean初始化以前执行beanProccessors Object bean = resolveBeforeInstantiation(beanName, mbdToUse);
进入
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#resolveBeforeInstantiation
@Nullable
protected Object resolveBeforeInstantiation(String beanName, RootBeanDefinition mbd) {
Object bean = null;
if (!Boolean.FALSE.equals(mbd.beforeInstantiationResolved)) {
// Make sure bean class is actually resolved at this point.
if (!mbd.isSynthetic() && hasInstantiationAwareBeanPostProcessors()) {
Class<?> targetType = determineTargetType(beanName, mbd);
if (targetType != null) {
// 调用bean初始化前处理器
bean = applyBeanPostProcessorsBeforeInstantiation(targetType, beanName);
if (bean != null) {
// bean初始化之后调用处理器
bean = applyBeanPostProcessorsAfterInitialization(bean, beanName);
}
}
}
mbd.beforeInstantiationResolved = (bean != null);
}
return bean;
}
返回
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#createBean(java.lang.String, org.springframework.beans.factory.support.RootBeanDefinition, java.lang.Object[])
这一行
// bean建立 Object beanInstance = doCreateBean(beanName, mbdToUse, args);
返回
org.springframework.beans.factory.support.AbstractBeanFactory#doGetBean
这一行
若是类型不一致进行类型转换 T convertedBean = getTypeConverter().convertIfNecessary(bean, requiredType);
返回
org.springframework.beans.factory.support.DefaultListableBeanFactory#preInstantiateSingletons
这一行
for (String beanName : beanNames) {
Object singletonInstance = getSingleton(beanName);
if (singletonInstance instanceof SmartInitializingSingleton) {
final SmartInitializingSingleton smartSingleton = (SmartInitializingSingleton) singletonInstance;
if (System.getSecurityManager() != null) {
AccessController.doPrivileged((PrivilegedAction<Object>) () -> {
// 单例bean建立完成后回调
smartSingleton.afterSingletonsInstantiated();
return null;
}, getAccessControlContext());
}
else {
smartSingleton.afterSingletonsInstantiated();
}
}
}
bean初始化之后触发回调
这一行
单例bean建立完成后回调 smartSingleton.afterSingletonsInstantiated();
返回
org.springframework.context.support.AbstractApplicationContext#refresh
这一行 bean初始化、依赖注入
finishBeanFactoryInitialization(beanFactory);
最后
本次介绍到这里，以上内容仅供参考。