Package org.dellroad.stuff.pobj

package org.dellroad.stuff.pobj

Simple XML Persistence Objects (POBJ).

This package implements a library for simple persistence of Java objects via XML. It's targeted at Java data structures that are small enough to fit in memory and which are read much more often than they are written, and can be persisted as an XML file. A good example would be configuration information for an application.

Attributes and features:

• Able to persist an arbitrary java object graph - you supply the XML (de)serialization strategy
• Automatic support for deep copying the object graph
• Read access uses natural Java
• Changes are atomic, serialized, wholesale updates
• All changes must fully validate
• Versioning support for optimistic locking
• Support for "out-of-band" persistent file updates
• Support for automatic re-indexing on change
• Support for listener notifications on update
• Support for schema updates via XSLT transforms using the org.dellroad.stuff.schema classes
• Support for JTA/XA transactions

The primary class is PersistentObject. Typically this class would be accessed through a PersistentObjectSchemaUpdater which allows for evolution of the XML schema over time; see SpringPersistentObjectSchemaUpdater for an example of Spring configuration.

A PersistentObjectTransactionManager for use with Spring's transaction support is also provided.

See Also:

• The dellroad-stuff Project

Class	Description
AbstractConfiguredBean<ROOT,T>	Support superclass for Spring beans that are configured by a PersistentObject root object, or some portion thereof.
AbstractDelegate<T>	Support superclass for PersistentObjectDelegate classes, with implementations of all methods other than serialize() and deserialize().
FilterDelegate<T>	Adapter class for PersistentObjectDelegate implementations that wrap a nested delegate.
NotConfiguredException	Thrown by AbstractConfiguredBean.getRequiredConfig() when the bean is not configured.
PersistentFileTransaction	Represents an open "transaction" on a PersistentObject's persistent file.
PersistentObject<T>	Main class for Simple XML Persistence Objects (POBJ).
PersistentObjectDelegate<T>	Delegate interface required for PersistentObjects.
PersistentObjectEvent<T>	Notification event emitted by a PersistentObject to listeners whenever there is an update to the root object.
PersistentObjectException	Runtime exception thrown during PersistentObject operations.
PersistentObjectExceptionTranslator	PersistentObject implementation of Spring's PersistenceExceptionTranslator interface.
PersistentObjectListener<T>	Listener interface for changes to a PersistentObject.
PersistentObjectSchemaUpdater<T>	A PersistentObjectDelegate that is also a AbstractSchemaUpdater that automatically applies needed updates to the persistent XML file.
PersistentObjectTransactionManager<T>	PersistentObject implementation of Spring's PlatformTransactionManager interface, allowing methods annotated with Spring's @Transactional annotation to perform transactions on PersistentObjects.
PersistentObjectValidationException	Runtime exception thrown during PersistentObject operations.
PersistentObjectVersionException	Optimistic locking exception thrown by PersistentObject.setRoot() when the expected version number does not agree.
SpringDelegate<T>	PersistentObjectDelegate that uses Spring's Marshaller and Unmarshaller interfaces for XML conversion.
SpringPersistentObjectSchemaUpdate<T>	Support superclass for Spring-enabled SchemaUpdates for use with a PersistentObjectSchemaUpdater.
SpringPersistentObjectSchemaUpdater<T>	PersistentObjectSchemaUpdater optimized for use with Spring: SpringPersistentObjectSchemaUpdater.getOrderingTieBreaker() is overridden to break ties by ordering updates in the same order as they are defined in the bean factory. This class implements InitializingBean and verifies all required properties are set. If no updates are explicitly configured, then all SpringPersistentObjectSchemaUpdates found in the containing bean factory are automatically configured; this requires that all of the schema updates are defined in the same ListableBeanFactory. The default value may be configured as an XML resource
SpringXSLPersistentObjectSchemaUpdate<T>	SpringPersistentObjectSchemaUpdate that applies a configured XSL transform to the XML form of the persistent object.
SpringXSLUpdateTransformConfigurer	Spring BeanPostProcessor that looks for SpringXSLPersistentObjectSchemaUpdate beans that don't have an explicit transform resource configured, and configures them using a resource location based on the bean name, by simply adding a configured prefix and suffix.
UpdatesXMLStreamReader	AnnotatedXMLStreamReader that reads the nested schema update list.
UpdatesXMLStreamWriter	AnnotatedXMLStreamWriter that inserts the schema update list into the document using an PersistentObjectSchemaUpdater.UPDATES_ELEMENT_NAME annotation element.