org.smallmind.persistence.orm.hibernate.ScrollIterator.java Source code

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Here is the source code for org.smallmind.persistence.orm.hibernate.ScrollIterator.java

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/*
 * Copyright (c) 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015 David Berkman
 * 
 * This file is part of the SmallMind Code Project.
 * 
 * The SmallMind Code Project is free software, you can redistribute
 * it and/or modify it under the terms of GNU Affero General Public
 * License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 * 
 * The SmallMind Code Project 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
 * General Public License for more details.
 * 
 * You should have received a copy of the the GNU Affero General Public
 * License, along with the SmallMind Code Project. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * Additional permission under the GNU Affero GPL version 3 section 7
 * ------------------------------------------------------------------
 * If you modify this Program, or any covered work, by linking or
 * combining it with other code, such other code is not for that reason
 * alone subject to any of the requirements of the GNU Affero GPL
 * version 3.
 */
package org.smallmind.persistence.orm.hibernate;

import java.util.Iterator;
import java.util.NoSuchElementException;
import org.hibernate.ScrollableResults;

public class ScrollIterator<T> implements Iterator<T>, Iterable<T> {

    private ScrollableResults scrollableResults;

    private Class<T> managedClass;

    private boolean more;

    public ScrollIterator(ScrollableResults scrollableResults, Class<T> managedClass) {

        this.scrollableResults = scrollableResults;
        this.managedClass = managedClass;

        more = scrollableResults.first();
    }

    public Iterator<T> iterator() {

        return this;
    }

    public boolean hasNext() {

        return more;
    }

    public T next() {

        if (!more) {
            throw new NoSuchElementException();
        }

        try {

            Object[] result;

            return managedClass
                    .cast((managedClass.isArray() && ((result = scrollableResults.get()).length > 1)) ? result
                            : scrollableResults.get(0));
        } finally {
            more = scrollableResults.next();
        }
    }

    public void remove() {

        throw new UnsupportedOperationException();
    }
}