Package de.schwarzrot.data.access

provides the working class for the anonymous Persistence layer.

See:
Description

Interface Summary

DataAccessor	interface for anonymous data access.
EntityDescriptorAccessor	As each EntityManager may need different amount of meta-information, it should be all accessible through the same interface.
EntityManager	is a manger to handle retrieval, saving and removal of entities to/from persistence.
Exporter	interface to implement export functionality.
Importer	interface to implement import functionality.
UserNameProvider	EntityManagers need to know the name of the user, as well as the SecurityManager, so this interface allows a generic access to the username.

Class Summary

DelegatingResourceBundleMessageSource	special implementation of a HierarchicalMessageSource, that can be extended at runtime.
EntityHolder	another wrapper around HashMap, used to cache entity instances already read from persistence.
NullEntityManager	serves as a "remainder" for developers, that a certain entity is not handled the right way.
PropertyAccessor	helper class to allow anonymous access to a property of a bean.
Repository	application proxy to persistence.
TransactionResource<T>	a wrapper class for the persistence handles used by EntityManagers.

Package de.schwarzrot.data.access Description

provides the working class for the anonymous Persistence layer. Applications proxy to persistence was Repository, which now has moved behind the curtain. The new application proxy to persistence is the application service de.schwarzrot.access.TransactionFactory.

The persistence layer makes heavy use of reflection. As reflection is an expensive operation, the results are cached, so that each businessclass will be introspected only once.

On a persistence call, the Repository looks for an EntityManager, configured to handle that type of business class and delegates the job to it. The EntityManager asks the EntityIntrospector for the type information of the business-class of interest, which is an EntityDescriptor, similar to the java Class type. It contains (meta-)information about a business class and its persistence, so each EntityManager may have its own EntityDescriptor.