org.hibernate.proxy

Class AbstractLazyInitializer

java.lang.Object

org.hibernate.proxy.AbstractLazyInitializer

All Implemented Interfaces:

LazyInitializer

Direct Known Subclasses:

BasicLazyInitializer, Dom4jLazyInitializer, MapLazyInitializer

public abstract class AbstractLazyInitializer
extends Object
implements LazyInitializer

Convenience base class for lazy initialization handlers. Centralizes the basic plumbing of doing lazy initialization freeing subclasses to acts as essentially adapters to their intended entity mode and/or proxy generation strategy.

Author:

Gavin King

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractLazyInitializer() For serialization from the non-pojo initializers (HHH-3309)
protected	AbstractLazyInitializer(String entityName, Serializable id, SessionImplementor session) Main constructor.

Method Summary

Modifier and Type	Method and Description
String	getEntityName() The entity-name of the entity our owning proxy represents.
Serializable	getIdentifier() Retrieve the identifier value for the enity our owning proxy represents.
Object	getImplementation() Return the underlying persistent object, initializing if necessary
Object	getImplementation(SessionImplementor s) Return the underlying persistent object in the given Session, or null, do not initialize the proxy
SessionImplementor	getSession() Get the session to which this proxy is associated, or null if it is not attached.
protected Object	getTarget() Getter for property 'target'.
void	initialize() Initialize the proxy, fetching the target entity if necessary.
protected boolean	isConnectedToSession() Getter for property 'connectedToSession'.
boolean	isReadOnly() Is the proxy read-only?.
protected Boolean	isReadOnlyBeforeAttachedToSession() Get the read-only/modifiable setting that should be put in affect when it is attached to a session.
boolean	isReadOnlySettingAvailable() Is the proxy's read-only/modifiable setting available?
boolean	isUninitialized() Is the proxy uninitialzed?
boolean	isUnwrap()
void	setIdentifier(Serializable id) Set the identifier value for the enity our owning proxy represents.
void	setImplementation(Object target) Initialize the proxy manually by injecting its target.
void	setReadOnly(boolean readOnly) Set an associated modifiable proxy to read-only mode, or a read-only proxy to modifiable mode.
void	setSession(SessionImplementor s) Associate the proxy with the given session.
void	setUnwrap(boolean unwrap)
void	unsetSession() Unset this initializer's reference to session.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.hibernate.proxy.LazyInitializer

getPersistentClass

Constructor Detail

AbstractLazyInitializer

protected AbstractLazyInitializer()

For serialization from the non-pojo initializers (HHH-3309)

AbstractLazyInitializer

protected AbstractLazyInitializer(String entityName,
                                  Serializable id,
                                  SessionImplementor session)

Main constructor.

Parameters:

entityName - The name of the entity being proxied.

id - The identifier of the entity being proxied.

session - The session owning the proxy.

Method Detail

getEntityName

public final String getEntityName()

The entity-name of the entity our owning proxy represents.

Specified by:

getEntityName in interface LazyInitializer

Returns:

The entity-name.

getIdentifier

public final Serializable getIdentifier()

Retrieve the identifier value for the enity our owning proxy represents.

Specified by:

getIdentifier in interface LazyInitializer

Returns:

The identifier value.

setIdentifier

public final void setIdentifier(Serializable id)

Set the identifier value for the enity our owning proxy represents.

Specified by:

setIdentifier in interface LazyInitializer

Parameters:

id - The identifier value.

isUninitialized

public final boolean isUninitialized()

Is the proxy uninitialzed?

Specified by:

isUninitialized in interface LazyInitializer

Returns:

True if uninitialized; false otherwise.

getSession

public final SessionImplementor getSession()

Get the session to which this proxy is associated, or null if it is not attached.

Specified by:

getSession in interface LazyInitializer

Returns:

The associated session.

setSession

public final void setSession(SessionImplementor s)
                      throws HibernateException

Associate the proxy with the given session.

Care should be given to make certain that the proxy is added to the session's persistence context as well to maintain the symetry of the association. That must be done seperately as this method simply sets an internal reference. We do also check that if there is already an associated session that the proxy reference was removed from that previous session's persistence contet.

Specified by:

setSession in interface LazyInitializer

Parameters:

s - The session

Throws:

HibernateException - Indicates that the proxy was still contained in the persistence context of the "previous session".

unsetSession

public final void unsetSession()

Unset this initializer's reference to session. It is assumed that the caller is also taking care or cleaning up the owning proxy's reference in the persistence context.

Generally speaking this is intended to be called only during Session.evict(java.lang.Object) and Session.clear() processing; most other use-cases should call LazyInitializer.setSession(org.hibernate.engine.SessionImplementor) instead.

Specified by:

unsetSession in interface LazyInitializer

initialize

public final void initialize()
                      throws HibernateException

Initialize the proxy, fetching the target entity if necessary.

Specified by:

initialize in interface LazyInitializer

Throws:

HibernateException - Indicates a problem initializing the proxy.

isConnectedToSession

protected final boolean isConnectedToSession()

Getter for property 'connectedToSession'.

Returns:

Value for property 'connectedToSession'.

getImplementation

public final Object getImplementation()

Return the underlying persistent object, initializing if necessary

Specified by:

getImplementation in interface LazyInitializer

Returns:

The underlying target entity.

setImplementation

public final void setImplementation(Object target)

Initialize the proxy manually by injecting its target.

Specified by:

setImplementation in interface LazyInitializer

Parameters:

target - The proxy target (the actual entity being proxied).

getImplementation

public final Object getImplementation(SessionImplementor s)
                               throws HibernateException

Return the underlying persistent object in the given Session, or null, do not initialize the proxy

Specified by:

getImplementation in interface LazyInitializer

Parameters:

s - The session to check

Returns:

The target, or null.

Throws:

HibernateException - Indicates problem locating the target.

getTarget

protected final Object getTarget()

Getter for property 'target'.

Same as getImplementation() except that this method will not force initialization.

Returns:

Value for property 'target'.

isReadOnlySettingAvailable

public final boolean isReadOnlySettingAvailable()

Is the proxy's read-only/modifiable setting available?

Specified by:

isReadOnlySettingAvailable in interface LazyInitializer

Returns:

true, if the setting is available false, if the proxy is detached or its associated session is closed

isReadOnly

public final boolean isReadOnly()

Is the proxy read-only?. The read-only/modifiable setting is not available when the proxy is detached or its associated session is closed. To check if the read-only/modifiable setting is available:

Specified by:

isReadOnly in interface LazyInitializer

Returns:

true, if this proxy is read-only; false, otherwise

See Also:

LazyInitializer.isReadOnlySettingAvailable(), Session.isReadOnly(Object entityOrProxy)

setReadOnly

public final void setReadOnly(boolean readOnly)

Set an associated modifiable proxy to read-only mode, or a read-only proxy to modifiable mode. If the proxy is currently initialized, its implementation will be set to the same mode; otherwise, when the proxy is initialized, its implementation will have the same read-only/ modifiable setting as the proxy. In read-only mode, no snapshot is maintained and the instance is never dirty checked. If the associated proxy already has the specified read-only/modifiable setting, then this method does nothing.

Specified by:

setReadOnly in interface LazyInitializer

See Also:

Session.setReadOnly(Object entityOrProxy, boolean readOnly)

isReadOnlyBeforeAttachedToSession

protected final Boolean isReadOnlyBeforeAttachedToSession()

Get the read-only/modifiable setting that should be put in affect when it is attached to a session. This method should only be called during serialization when read-only/modifiable setting is not available (i.e., isReadOnlySettingAvailable() == false)

Throws:

IllegalStateException - if isReadOnlySettingAvailable() == true

isUnwrap

public boolean isUnwrap()

Specified by:

isUnwrap in interface LazyInitializer

setUnwrap

public void setUnwrap(boolean unwrap)

Specified by:

setUnwrap in interface LazyInitializer