/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.proxy;
import java.io.Serializable;
import org.hibernate.HibernateException;
import org.hibernate.engine.spi.SessionImplementor;
/**
* Handles fetching of the underlying entity for a proxy
*
* @author Gavin King
* @author Steve Ebersole
*/
public interface LazyInitializer {
/**
* Initialize the proxy, fetching the target entity if necessary.
*
* @throws HibernateException Indicates a problem initializing the proxy.
*/
public void initialize() throws HibernateException;
/**
* Retrieve the identifier value for the entity our owning proxy represents.
*
* @return The identifier value.
*/
public Serializable getIdentifier();
/**
* Set the identifier value for the entity our owning proxy represents.
*
* @param id The identifier value.
*/
public void setIdentifier(Serializable id);
/**
* The entity-name of the entity our owning proxy represents.
*
* @return The entity-name.
*/
public String getEntityName();
/**
* Get the actual class of the entity. Generally, {@link #getEntityName()} should be used instead.
*
* @return The actual entity class.
*/
public Class getPersistentClass();
/**
* Is the proxy uninitialzed?
*
* @return True if uninitialized; false otherwise.
*/
public boolean isUninitialized();
/**
* Return the underlying persistent object, initializing if necessary
*
* @return The underlying target entity.
*/
public Object getImplementation();
/**
* Return the underlying persistent object in the given session, or null if not contained in this session's
* persistence context.
*
* @param session The session to check
*
* @return The target, or null.
*
* @throws HibernateException Indicates problem locating the target.
*/
public Object getImplementation(SessionImplementor session) throws HibernateException;
/**
* Initialize the proxy manually by injecting its target.
*
* @param target The proxy target (the actual entity being proxied).
*/
public void setImplementation(Object target);
/**
* Is the proxy's read-only/modifiable setting available?
* @return true, if the setting is available
* false, if the proxy is detached or its associated session is closed
*/
public boolean isReadOnlySettingAvailable();
/**
* 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:
* @see org.hibernate.proxy.LazyInitializer#isReadOnlySettingAvailable()
*
* @return true, if this proxy is read-only; false, otherwise
* @throws org.hibernate.TransientObjectException if the proxy is detached (getSession() == null)
* @throws org.hibernate.SessionException if the proxy is associated with a sesssion that is closed
*
* @see org.hibernate.Session#isReadOnly(Object entityOrProxy)
*/
public boolean isReadOnly();
/**
* 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.
*
* @param readOnly if true, the associated proxy is made read-only;
* if false, the associated proxy is made modifiable.
* @throws org.hibernate.TransientObjectException if the proxy is not association with a session
* @throws org.hibernate.SessionException if the proxy is associated with a sesssion that is closed
*
* @see {@link org.hibernate.Session#setReadOnly(Object entityOrProxy, boolean readOnly)}
*/
public void setReadOnly(boolean readOnly);
/**
* Get the session to which this proxy is associated, or null if it is not attached.
*
* @return The associated session.
*/
public SessionImplementor getSession();
/**
* Associate the proxy with the given session.
* <p/>
* 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.
*
* @param session The session
* @throws HibernateException Indicates that the proxy was still contained in the persistence context of the
* "previous session".
*/
public void setSession(SessionImplementor session) throws HibernateException;
/**
* 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.
* <p/>
* Generally speaking this is intended to be called only during {@link org.hibernate.Session#evict} and
* {@link org.hibernate.Session#clear} processing; most other use-cases should call {@link #setSession} instead.
*/
public void unsetSession();
public void setUnwrap(boolean unwrap);
public boolean isUnwrap();
}