Hibernate example source code file (ScrollableResultsImpl.java)

This example Hibernate source code file (ScrollableResultsImpl.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

abstractscrollableresults, hibernateexception, hibernateexception, jdbc, loader, mappingexception, object, object, resultset, scrollableresults, scrollableresultsimpl, scrollableresultsimpl, sql, sqlexception, sqlexception, type

The Hibernate ScrollableResultsImpl.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2008-2011, 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.internal;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.hibernate.HibernateException;
import org.hibernate.MappingException;
import org.hibernate.ScrollableResults;
import org.hibernate.engine.spi.QueryParameters;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.hql.internal.HolderInstantiator;
import org.hibernate.loader.Loader;
import org.hibernate.type.Type;

/**
 * Implementation of the <tt>ScrollableResults interface
 * @author Gavin King
 */
public class ScrollableResultsImpl extends AbstractScrollableResults implements ScrollableResults {

	private Object[] currentRow;

	public ScrollableResultsImpl(
	        ResultSet rs,
	        PreparedStatement ps,
	        SessionImplementor sess,
	        Loader loader,
	        QueryParameters queryParameters,
	        Type[] types, HolderInstantiator holderInstantiator) throws MappingException {
		super( rs, ps, sess, loader, queryParameters, types, holderInstantiator );
	}

	protected Object[] getCurrentRow() {
		return currentRow;
	}

	/**
	 * @see org.hibernate.ScrollableResults#scroll(int)
	 */
	public boolean scroll(int i) throws HibernateException {
		try {
			boolean result = getResultSet().relative(i);
			prepareCurrentRow(result);
			return result;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"could not advance using scroll()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#first()
	 */
	public boolean first() throws HibernateException {
		try {
			boolean result = getResultSet().first();
			prepareCurrentRow(result);
			return result;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"could not advance using first()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#last()
	 */
	public boolean last() throws HibernateException {
		try {
			boolean result = getResultSet().last();
			prepareCurrentRow(result);
			return result;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"could not advance using last()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#next()
	 */
	public boolean next() throws HibernateException {
		try {
			boolean result = getResultSet().next();
			prepareCurrentRow(result);
			return result;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"could not advance using next()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#previous()
	 */
	public boolean previous() throws HibernateException {
		try {
			boolean result = getResultSet().previous();
			prepareCurrentRow(result);
			return result;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"could not advance using previous()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#afterLast()
	 */
	public void afterLast() throws HibernateException {
		try {
			getResultSet().afterLast();
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"exception calling afterLast()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#beforeFirst()
	 */
	public void beforeFirst() throws HibernateException {
		try {
			getResultSet().beforeFirst();
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"exception calling beforeFirst()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#isFirst()
	 */
	public boolean isFirst() throws HibernateException {
		try {
			return getResultSet().isFirst();
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"exception calling isFirst()"
				);
		}
	}

	/**
	 * @see org.hibernate.ScrollableResults#isLast()
	 */
	public boolean isLast() throws HibernateException {
		try {
			return getResultSet().isLast();
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"exception calling isLast()"
				);
		}
	}

	public int getRowNumber() throws HibernateException {
		try {
			return getResultSet().getRow()-1;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"exception calling getRow()"
				);
		}
	}

	public boolean setRowNumber(int rowNumber) throws HibernateException {
		if (rowNumber>=0) rowNumber++;
		try {
			boolean result = getResultSet().absolute(rowNumber);
			prepareCurrentRow(result);
			return result;
		}
		catch (SQLException sqle) {
			throw getSession().getFactory().getSQLExceptionHelper().convert(
					sqle,
					"could not advance using absolute()"
				);
		}
	}

	private void prepareCurrentRow(boolean underlyingScrollSuccessful) 
	throws HibernateException {
		
		if (!underlyingScrollSuccessful) {
			currentRow = null;
			return;
		}

		Object result = getLoader().loadSingleRow(
				getResultSet(),
				getSession(),
				getQueryParameters(),
				false
		);
		if ( result != null && result.getClass().isArray() ) {
			currentRow = (Object[]) result;
		}
		else {
			currentRow = new Object[] { result };
		}

		if ( getHolderInstantiator() != null ) {
			currentRow = new Object[] { getHolderInstantiator().instantiate(currentRow) };
		}

		afterScrollOperation();
	}

}