Spring Bean 的初始化过程.... 

执行过程
FileSystemXmlApplicationContext
    ↓
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
刷新入口
    ↓
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
实例化所有的(non-lazy-init)单例 
    ↓
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
Instantiate all remaining (non-lazy-init) singletons，进行遍历
    ↓
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
调用获取动作doGetBean
    ↓
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
获取共享实例sharedInstance
    ↓
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
创建了一个内部的ObjectFactory，定义了一个内部getObject方法，然后
    ↓
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
调用父类实现的createBean方法
    ↓
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
判断一些条件后调用执行方法doCreateBean
    ↓
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
大部分实例动作的包装类（包括485的createBeanInstance--构建实例、）
    ↓
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1118)
填充数据（下面就是判断、遍历填充数据）
    ↓
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1360)
    ↓
org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:153)
    ↓
org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveManagedList(BeanDefinitionValueResolver.java:353)
    ↓
org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:194)


AbstractAutowireCapableBeanFactory的：createBeanInstance
方法最后面
// Need to determine the constructor...
Constructor[] ctors = determineConstructorsFromBeanPostProcessors(beanClass, beanName);
if (ctors != null ||
        mbd.getResolvedAutowireMode() == RootBeanDefinition.AUTOWIRE_CONSTRUCTOR ||
        mbd.hasConstructorArgumentValues() || !ObjectUtils.isEmpty(args))  {
    return autowireConstructor(beanName, mbd, ctors, args);
}

// No special handling: simply use no-arg constructor.
return instantiateBean(beanName, mbd);