Hibernate example source code file (ForUpdateFragment.java)

This example Hibernate source code file (ForUpdateFragment.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

dialect, forupdatefragment, forupdatefragment, illegalargumentexception, iterator, lockmode, lockmode, lockoptions, map, queryexception, queryexception, string, string, stringbuffer, util

The Hibernate ForUpdateFragment.java source code

/*
 * 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.sql;

import java.util.Iterator;
import java.util.Map;
import org.hibernate.LockMode;
import org.hibernate.LockOptions;
import org.hibernate.QueryException;
import org.hibernate.dialect.Dialect;
import org.hibernate.internal.util.StringHelper;

/**
 * @author Gavin King
 */
public class ForUpdateFragment {
	private final StringBuffer aliases = new StringBuffer();
	private boolean isNowaitEnabled;
	private final Dialect dialect;
	private LockMode lockMode;
	private LockOptions lockOptions;

	public ForUpdateFragment(Dialect dialect) {
		this.dialect = dialect;
	}

	public ForUpdateFragment(Dialect dialect, LockOptions lockOptions, Map keyColumnNames) throws QueryException {
		this( dialect );
		LockMode upgradeType = null;
		Iterator iter = lockOptions.getAliasLockIterator();
		this.lockOptions =  lockOptions;

		if ( !iter.hasNext()) {  // no tables referenced
			final LockMode lockMode = lockOptions.getLockMode();
			if ( LockMode.READ.lessThan( lockMode ) ) {
				upgradeType = lockMode;
				this.lockMode = lockMode;
			}
		}

		while ( iter.hasNext() ) {
			final Map.Entry me = ( Map.Entry ) iter.next();
			final LockMode lockMode = ( LockMode ) me.getValue();
			if ( LockMode.READ.lessThan( lockMode ) ) {
				final String tableAlias = ( String ) me.getKey();
				if ( dialect.forUpdateOfColumns() ) {
					String[] keyColumns = ( String[] ) keyColumnNames.get( tableAlias ); //use the id column alias
					if ( keyColumns == null ) {
						throw new IllegalArgumentException( "alias not found: " + tableAlias );
					}
					keyColumns = StringHelper.qualify( tableAlias, keyColumns );
					for ( int i = 0; i < keyColumns.length; i++ ) {
						addTableAlias( keyColumns[i] );
					}
				}
				else {
					addTableAlias( tableAlias );
				}
				if ( upgradeType != null && lockMode != upgradeType ) {
					throw new QueryException( "mixed LockModes" );
				}
				upgradeType = lockMode;
			}
		}

		if ( upgradeType == LockMode.UPGRADE_NOWAIT ) {
			setNowaitEnabled( true );
		}
	}

	public ForUpdateFragment addTableAlias(String alias) {
		if ( aliases.length() > 0 ) {
			aliases.append( ", " );
		}
		aliases.append( alias );
		return this;
	}

	public String toFragmentString() {
		if ( lockOptions!= null ) {
			return dialect.getForUpdateString( aliases.toString(), lockOptions );
		}
		else if ( aliases.length() == 0) {
			if ( lockMode != null ) {
				return dialect.getForUpdateString( lockMode );
			}
			return "";
		}
		// TODO:  pass lockmode
		return isNowaitEnabled ?
				dialect.getForUpdateNowaitString( aliases.toString() ) :
				dialect.getForUpdateString( aliases.toString() );
	}

	public ForUpdateFragment setNowaitEnabled(boolean nowait) {
		isNowaitEnabled = nowait;
		return this;
	}
}