DefaultSingletonBeanRegistry

earlySingletonObjects: contains bean haven't been injected.
dependentBeanMap: <bean -- set bean called the key bean>
dependenciesForBeanMap: <bean -- set bean  be called by the key bean>
containedBeanMap: <bean -- set bean be contained>
desposableBeans: <bean -- bean that actually exec destroy function >

1.add
1.1 addSingleton
add to singletonObjects
remove from singletonFactories
remove from earlySingletonObjects
add to registeredSingletons
1.2 addSingletonFactory: resolve circular references
if singletonObjects not contains then bean,then
remove from singletonFactories
remove from earlySingletonObjects
add to registeredSingletons
end if;


1.3 registerDisposableBean
add to disposableBeans,

1.4 registerDependentBean
add to dependentBeanMap
add to dependenciesForBeanMap

1.5 registerContainedBean
add to containedBeanMap
add to dependentBeanMap
add to dependenciesForBeanMap


2.get
2.1 get with ObjectFactory
search singletonObjects
if singletonObjects not have , then
call beforeSingletonCreation
get from ObjectFactory
call afterSingletonCreation
add to singletonObjects
remove from singletonFactories
remove from earlySingletonObjects
add to registeredSingletons
end if;
2.2 get with none ObjectFactory
search singletonObjects
if singletonObjects not have ,then
search earlySingletonObjects
if not have , then
get from ObjectFactory
add to earlySingletonObjects
remove from singletonFactories
add to singletonObjects
end if;
end if;

3.select if exists
search singletonObjects

4.destory
4.1 destory single element
remove from singletonObjects
remove from singleFactories
remove from earlySingletonObjects
remove from registeredSingletons
remove from disposableBeans
destory beans that called this bean
destory this
destory contained beans
remove from dependentBeanMap (remove reference for this bean called)
remove from dependenciesForBeanMap