自定义属性解析器
org.springframework.context.support.AbstractApplicationContext#prepareBeanFactory
beanFactory.setBeanClassLoader(getClassLoader());
//设置EL表达式解析器（${}）
beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
//设置默认的属性解析器
beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
PropertyEditorSupport属性编辑器
<bean class="org.springframework.beans.factory.config.CustomEditorConfigurer">
<property name="customEditors">
<map>
<entry key="cn.com.luofu.selfEditor.Address" value="cn.com.luofu.selfEditor.AddressPropertyEditor"></entry>
</map>
</property>
</bean>
//属性编辑器注入
org.springframework.context.support.AbstractApplicationContext#invokeBeanFactoryPostProcessors->invokeBeanFactoryPostProcessors->invokeBeanFactoryPostProcessors->postProcessBeanFactory{
//beanfactory中customEditors的map中添加对应属性解析器
...this.customEditors.forEach(beanFactory::registerCustomEditor{
...this.customEditors.put(requiredType, propertyEditorClass)...
})
}
//实例化bean
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#doCreateBean{
...instanceWrapper = createBeanInstance{
...instantiateBean{
//BeanWrapperImpl extends AbstractNestablePropertyAccessor extends AbstractPropertyAccessor extends TypeConverterSupport extends PropertyEditorRegistrySupport 看出 BeanWrapperImpl 继承 PropertyEditorRegistrySupport
...BeanWrapper bw = new BeanWrapperImpl
initBeanWrapper(bw){
registerCustomEditors(bw){
//这里registry为传进来的bw，this为beanfactory(上面自定义解析器已经添加到了工厂)
...this.customEditors.forEach((requiredType, editorClass) ->
registry.registerCustomEditor(requiredType, BeanUtils.instantiateClass(editorClass))){
//PropertyEditorRegistrySupport属性customEditors加了自定义属性解析器
...this.customEditors.put(requiredType, propertyEditor)...
}
}
}...
}...
}...
}
//属性编辑器获取
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#populateBean{
...applyPropertyValues{
//处理value为依赖bean包括循环依赖
...valueResolver.resolveValueIfNecessary...
...convertForProperty->convertForProperty->convertForProperty->convertIfNecessary->convertIfNecessary{
...PropertyEditor editor = this.propertyEditorRegistry.findCustomEditor{
//从之前放进去的PropertyEditorRegistrySupport#findCustomEditor
...getCustomEditor{
//取出对应的edit如AddressPropertyEditor
...this.customEditors.get(requiredType)...
}...
}...
//对应的edit属性解析器解析
...doConvertValue->doConvertTextValue->editor.setAsText
}...
}...
}
ConversionService属性编辑器
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#convertForProperty->convertForProperty...->convertIfNecessary..->canConvert->conversionService.convert //从GenericConversionService属性converters中获取解析器，自定义convert需要实现Converter接口。如：StudentConverter implements Converter<String,Student>
Spel 表达式
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory#applyPropertyValues{
//convertForProperty 上面两个解析器 在el处理之后在处理
...resolveValueIfNecessary{
...else if (value instanceof TypedStringValue) {
...evaluate{
...doEvaluate->evaluateBeanDefinitionString->evaluate{
//el 解析器解析
...this.expressionParser.parseExpression{
...parseTemplate{
...parseExpressions{
... //#{和} 解析#{person.hobit}
String prefix = context.getExpressionPrefix();
String suffix = context.getExpressionSuffix()...
}...
}...
}...
return expr.getValue(sec){
...getValue->getValueInternalgetValueRef->getValueInternal->getValueInternal->readProperty->read->getObject->getBean(key) @1
}
}...
}...
}
}...
}
// @1 将person.hobit拆分person和hobit分别解析
org.springframework.beans.factory.config.BeanExpressionContext#getObject{
//key: person，然后通过反射获取属性值org.springframework.expression.spel.support.ReflectivePropertyAccessor.OptimalPropertyAccessor#read->method.invoke(target)
...this.beanFactory.getBean(key)...
}
循环依赖
<bean name="person" class="cn.com.luofu.dto.Person">
<property name="hobit" value="zzz"></property>
<property name="film" ref="film"></property>
</bean>
<bean name="film" class="cn.com.luofu.el.Film">
<property name="name" value="lisi"></property>
<property name="person" ref="person"></property>
</bean>
org.springframework.beans.factory.support.AbstractBeanFactory#doGetBean{
... // Eagerly check singleton cache for manually registered singletons.
Object sharedInstance = getSingleton(beanName){
...getSingleton(beanName, true){
//依次从一二三级缓存获取singletonObjects、earlySingletonObjects、singletonFactories。此时bean还未标记singletonsCurrentlyInCreation(方法后面的getSingleton(beanName, () ->这个方法会标记)返回的为null.如果标记了接下来的代码会从二级缓存拿值放到二级缓存
}...
...getSingleton(beanName,()...){
...beforeSingletonCreation{
...this.singletonsCurrentlyInCreation.add(beanName)...
}...
...getObject{
//lumbdar
...doCreateBean{
//判读支持循环引用后（含标记singletonsCurrentlyInCreation为true）
...addSingletonFactory(beanName, () -> getEarlyBeanReference(beanName, mbd, bean)){
//实例化后放到三级缓存
...if (!this.singletonObjects.containsKey(beanName)) {
this.singletonFactories.put(beanName, singletonFactory);
this.earlySingletonObjects.remove(beanName);
this.registeredSingletons.add(beanName);
}...
}...
}...
}...
...afterSingletonCreation{
...this.singletonsCurrentlyInCreation.remove(beanName)...
}...
...addSingleton{
//实例化完成后放到一级缓存，从二级、三级缓存移除
...this.singletonObjects.put(beanName, singletonObject);
this.singletonFactories.remove(beanName);
this.earlySingletonObjects.remove(beanName);
this.registeredSingletons.add(beanName);...
}...
}...
}...
}
getbean("person")->