Hibernate example source code file (PessimisticForceIncrementLockingStrategy.java)

This example Hibernate source code file (PessimisticForceIncrementLockingStrategy.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

entityentry, entitypersister, hibernateexception, hibernateexception, io, jdbcexception, lockmode, lockmode, object, object, pessimisticforceincrementlockingstrategy, pessimisticforceincrementlockingstrategy, serializable, sessionimplementor, staleobjectstateexception

The Hibernate PessimisticForceIncrementLockingStrategy.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2010, Red Hat Inc. 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 Inc.
 *
 * 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.dialect.lock;
import java.io.Serializable;
import org.hibernate.HibernateException;
import org.hibernate.JDBCException;
import org.hibernate.LockMode;
import org.hibernate.StaleObjectStateException;
import org.hibernate.engine.spi.EntityEntry;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.persister.entity.EntityPersister;
import org.hibernate.persister.entity.Lockable;

/**
 * A pessimistic locking strategy that increments the version immediately (obtaining an exclusive write lock).
 * <p/>
 * This strategy is valid for LockMode.PESSIMISTIC_FORCE_INCREMENT
 *
 * @author Scott Marlow
 * @since 3.5
 */
public class PessimisticForceIncrementLockingStrategy implements LockingStrategy {
	private final Lockable lockable;
	private final LockMode lockMode;

	/**
	 * Construct locking strategy.
	 *
	 * @param lockable The metadata for the entity to be locked.
	 * @param lockMode Indicates the type of lock to be acquired.
	 */
	public PessimisticForceIncrementLockingStrategy(Lockable lockable, LockMode lockMode) {
		this.lockable = lockable;
		this.lockMode = lockMode;
		// ForceIncrement can be used for PESSIMISTIC_READ, PESSIMISTIC_WRITE or PESSIMISTIC_FORCE_INCREMENT
		if ( lockMode.lessThan( LockMode.PESSIMISTIC_READ ) ) {
			throw new HibernateException( "[" + lockMode + "] not valid for [" + lockable.getEntityName() + "]" );
		}
	}

	/**
	 * {@inheritDoc}
	 */
	public void lock(
			Serializable id,
			Object version,
			Object object,
			int timeout,
			SessionImplementor session) throws StaleObjectStateException, JDBCException {
		if ( !lockable.isVersioned() ) {
			throw new HibernateException( "[" + lockMode + "] not supported for non-versioned entities [" + lockable.getEntityName() + "]" );
		}
		EntityEntry entry = session.getPersistenceContext().getEntry( object );
		final EntityPersister persister = entry.getPersister();
		Object nextVersion = persister.forceVersionIncrement( entry.getId(), entry.getVersion(), session );
		entry.forceLocked( object, nextVersion );
	}

	/**
	 * Retrieve the specific lock mode defined.
	 *
	 * @return The specific lock mode.
	 */
	protected LockMode getLockMode() {
		return lockMode;
	}
}