/*

 * 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;

import javax.xml.stream.events.XMLEvent;

import java.util.Iterator;

/**

 *

 * This is the top level interface for parsing XML Events.  It provides

 * the ability to peek at the next event and returns configuration

 * information through the property interface.

 *

 * @version 1.0

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

 * @see XMLInputFactory

 * @see XMLEventWriter

 * @since 1.6

 */

public interface XMLEventReader extends Iterator<Object> {

  /**

   * Gets the next XMLEvent. The initial event is

   * {@link javax.xml.stream.events.StartDocument StartDocument}.

   *

   * @return the next XMLEvent

   * @see XMLEvent

   * @throws XMLStreamException if there is an error with the underlying XML.

   * @throws java.util.NoSuchElementException iteration has no more elements.

   */

  public XMLEvent nextEvent() throws XMLStreamException;

  /**

   * Check if there are more events.

   * Returns true if there are more events and false otherwise.

   * @return true if the event reader has more events, false otherwise

   */

  @Override

  public boolean hasNext();

  /**

   * Check the next XMLEvent without reading it from the stream.

   * Returns null if the stream is at EOF or has no more XMLEvents.

   * A call to peek() will be equal to the next return of next().

   *

   * @return the next XMLEvent

   * @see XMLEvent

   * @throws XMLStreamException if an error occurs

   */

  public XMLEvent peek() throws XMLStreamException;

  /**

   * Reads the content of a text-only element. Precondition:

   * the current event is START_ELEMENT. Postcondition:

   * The current event is the corresponding END_ELEMENT.

   *

   * @return the text of the element

   * @throws XMLStreamException if the current event is not a START_ELEMENT

   * or if a non text element is encountered

   */

  public String getElementText() throws XMLStreamException;

  /**

   * Skips any insignificant space events until a START_ELEMENT or

   * END_ELEMENT is reached. If anything other than space characters are

   * encountered, an exception is thrown. This method should

   * be used when processing element-only content because

   * the parser is not able to recognize ignorable whitespace if

   * the DTD is missing or not interpreted.

   *

   * @return a START_ELEMENT or END_ELEMENT

   * @throws XMLStreamException if anything other than space characters are encountered

   */

  public XMLEvent nextTag() throws XMLStreamException;

  /**

   * Get the value of a feature/property from the underlying implementation

   * @param name The name of the property

   * @return The value of the property

   * @throws IllegalArgumentException if the property is not supported

   */

  public Object getProperty(java.lang.String name) throws java.lang.IllegalArgumentException;

  /**

   * Frees any resources associated with this Reader.  This method does not close the

   * underlying input source.

   * @throws XMLStreamException if there are errors freeing associated resources

   */

  public void close() throws XMLStreamException;

}