co.codewizards.cloudstore.local.persistence

Class DAO<E extends Entity,D extends DAO<E,D>>

java.lang.Object

co.codewizards.cloudstore.local.persistence.DAO<E,D>

Direct Known Subclasses:

CopyModificationDAO, DeleteModificationDAO, DirectoryDAO, LastSyncToRemoteRepoDAO, LocalRepositoryDAO, ModificationDAO, NormalFileDAO, RemoteRepositoryDAO, RemoteRepositoryRequestDAO, RepoFileDAO

public abstract class DAO<E extends Entity,D extends DAO<E,D>>
extends Object

Base class for all data access objects (DAOs).

Usually an instance of a DAO is obtained using LocalRepoTransaction.getDAO(...).

Author:

Marco หงุ่ยตระกูล-Schulze - marco at nightlabs dot de

Constructor Summary

Constructors

Constructor and Description
DAO() Instantiate the DAO.

Method Summary

Methods

Modifier and Type	Method and Description
void	deletePersistent(E entity)
void	deletePersistentAll(Collection<? extends E> entities)
protected <T extends DAO<?,?>> T	getDAO(Class<T> daoClass)
Class<E>	getEntityClass() Get the type of the entity.
E	getObjectByIdOrFail(long id) Get the entity-instance referenced by the specified identifier.
E	getObjectByIdOrNull(long id) Get the entity-instance referenced by the specified identifier.
Collection<E>	getObjects()
long	getObjectsCount()
PersistenceManager	getPersistenceManager() Gets the PersistenceManager assigned to this DAO.
protected Collection<E>	load(Collection<E> entities)
<P extends E> P	makePersistent(P entity)
D	persistenceManager(PersistenceManager persistenceManager) Assigns the given PersistenceManager to this DAO and returns this.
protected PersistenceManager	pm()
void	setPersistenceManager(PersistenceManager persistenceManager) Assigns the given PersistenceManager to this DAO.
protected D	thisDAO()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DAO

public DAO()

Instantiate the DAO.

It is recommended not to invoke this constructor directly, but instead use LocalRepoTransaction.getDAO(...), if a LocalRepoTransaction is available (which should be in most situations).

After constructing, you must assign a PersistenceManager, before you can use the DAO. This is already done when using the LocalRepoTransaction's factory method.

Method Detail

getPersistenceManager

public PersistenceManager getPersistenceManager()

Gets the PersistenceManager assigned to this DAO.

Returns:

the PersistenceManager assigned to this DAO. May be null, if none was assigned, yet.

See Also:

setPersistenceManager(PersistenceManager), persistenceManager(PersistenceManager)

setPersistenceManager

public void setPersistenceManager(PersistenceManager persistenceManager)

Assigns the given PersistenceManager to this DAO.

The DAO cannot be used, before a non-null value was set using this method.

Parameters:

persistenceManager - the PersistenceManager to be used by this DAO. May be null, but a non-null value must be set to make this DAO usable.

See Also:

persistenceManager(PersistenceManager)

pm

protected PersistenceManager pm()

persistenceManager

public D persistenceManager(PersistenceManager persistenceManager)

Assigns the given PersistenceManager to this DAO and returns this.

This method delegates to setPersistenceManager(PersistenceManager).

Parameters:

persistenceManager - the PersistenceManager to be used by this DAO. May be null, but a non-null value must be set to make this DAO usable.

Returns:

this for a fluent API.

See Also:

setPersistenceManager(PersistenceManager)

thisDAO

protected D thisDAO()

getEntityClass

public Class<E> getEntityClass()

Get the type of the entity.

Returns:

the type of the entity; never null.

getObjectByIdOrFail

public E getObjectByIdOrFail(long id)
                                     throws JDOObjectNotFoundException

Get the entity-instance referenced by the specified identifier.

Parameters:

id - the identifier referencing the desired entity. Must not be null.

Returns:

the entity-instance referenced by the specified identifier. Never null.

Throws:

JDOObjectNotFoundException - if the entity referenced by the given identifier does not exist.

getObjectByIdOrNull

public E getObjectByIdOrNull(long id)

Get the entity-instance referenced by the specified identifier.

Parameters:

id - the identifier referencing the desired entity. Must not be null.

Returns:

the entity-instance referenced by the specified identifier or null, if no such entity exists.

getObjects

public Collection<E> getObjects()

getObjectsCount

public long getObjectsCount()

makePersistent

public <P extends E> P makePersistent(P entity)

deletePersistent

public void deletePersistent(E entity)

deletePersistentAll

public void deletePersistentAll(Collection<? extends E> entities)

load

protected Collection<E> load(Collection<E> entities)

getDAO

protected <T extends DAO<?,?>> T getDAO(Class<T> daoClass)