CachingComponent Represents a JIRA component that contains a cache. 
ComponentManager.State The state of the ComponentManager
InitializingComponent Similar to InitializingBean in Spring - this should be implemented by a component where you want to do some work immediately after registration 
JiraApplicationContext High level component that represents the single instance of JIRA. 
JiraDataType Defines a domain specific data type. 


ClusterServicesRegistrar Registers the cluster-related services. 
ComponentManager This component manager uses PicoContainer to resolve all the dependencies between components. 
DefaultHostContextAccessor This is necessary to provide a generic way for SAL to access a component that may not have been published the plugins 2.0 way. 
DefaultJiraApplicationContext Default singleton production implementation. 
JiraDataTypeImpl Each data type can specify a collection of actual java types, represented via their Class, that this type is. 
JiraDataTypes Defines the known data types
ManagerFactory Previously used to provide static methods for obtaining 'Manager' classes, now it only has globalRefresh()  
MultipleKeyRegistrant<T> Helper utility which helps to create single instance of object exposed under multiple keys 
NoopCacheEventListenerFactory Work-around for CACHE-95 / EHC-1089. 
NoopResourceTransformer This is an implementation of resource transformer that does not transform resource. 
WarmersRegistrar Register warmers for JIRA caches. 
WrappedComponentContainer This class holds reference to ComponentContainer used to instantiate objects