ListAccess.java

/*
 * Copyright (C) 2009 eXo Platform SAS.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.exoplatform.commons.utils;

/**
 * A Service Provider Interface for a list access.
 *
 * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
 * @version $Revision$
 * @LevelAPI Platform
 */
public interface ListAccess<E>
{

   /**
    * <p>Retrieves an array of object from the list. The returned array size is expected to
    * be equals to the length argument.</p>
    *
    * <p>The index value and the lenght value cannot be negative, and the sum of the index and
    * the length cannot be greater than the list size. Those values are considered as non correct.<p>
    *
    * @param index the index
    * @param length the limit
    * @return the array
    * @throws Exception any exception that would prevent access to the list
    * @throws IllegalArgumentException if the index value or the length value are not correct
    */
   E[] load(int index, int length) throws Exception, IllegalArgumentException;

   /**
    * Returns the list size.
    *
    * @return the size
    * @throws Exception any exception that would prevent access to the list
    */
   int getSize() throws Exception;

}