/*

 * Copyright (c) 2009, 2020, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package javax.xml.stream.util;

import javax.xml.stream.events.XMLEvent;

import javax.xml.stream.XMLStreamReader;

import javax.xml.stream.XMLStreamException;

/**

 * This interface defines a class that allows a user to register

 * a way to allocate events given an XMLStreamReader.  An implementation

 * is not required to use the XMLEventFactory implementation but this

 * is recommended.  The XMLEventAllocator can be set on an XMLInputFactory

 * using the property "javax.xml.stream.allocator"

 *

 * @version 1.0

 * @author Copyright (c) 2009 by Oracle Corporation. All Rights Reserved.

 * @see javax.xml.stream.XMLInputFactory

 * @see javax.xml.stream.XMLEventFactory

 * @since 1.6

 */

public interface XMLEventAllocator {

  /**

   * This method creates an instance of the XMLEventAllocator. This

   * allows the XMLInputFactory to allocate a new instance per reader.

   * @return an instance of the {@code XMLEventAllocator}

   */

  public XMLEventAllocator newInstance();

  /**

   * This method allocates an event given the current

   * state of the XMLStreamReader.  If this XMLEventAllocator

   * does not have a one-to-one mapping between reader states

   * and events this method will return null.  This method

   * must not modify the state of the XMLStreamReader.

   * @param reader The XMLStreamReader to allocate from

   * @return the event corresponding to the current reader state

   * @throws XMLStreamException if an error occurs

   */

  public XMLEvent allocate(XMLStreamReader reader)

    throws XMLStreamException;

  /**

   * This method allocates an event or set of events

   * given the current

   * state of the XMLStreamReader and adds the event

   * or set of events to the

   * consumer that was passed in.  This method can be used

   * to expand or contract reader states into event states.

   * This method may modify the state of the XMLStreamReader.

   * @param reader The XMLStreamReader to allocate from

   * @param consumer The XMLEventConsumer to add to.

   * @throws XMLStreamException if an error occurs

   */

  public void allocate(XMLStreamReader reader, XMLEventConsumer consumer)

    throws XMLStreamException;

}