1 /*
   2  * Copyright (c) 2009, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package javax.xml.stream;
  27 
  28 import javax.xml.stream.events.XMLEvent;
  29 
  30 import java.util.Iterator;
  31 
  32 /**
  33  *
  34  * This is the top level interface for parsing XML Events.  It provides
  35  * the ability to peek at the next event and returns configuration
  36  * information through the property interface.
  37  *
  38  * @version 1.0
  39  * @author Copyright (c) 2009 by Oracle Corporation. All Rights Reserved.
  40  * @see XMLInputFactory
  41  * @see XMLEventWriter
  42  * @since 1.6
  43  */
  44 public interface XMLEventReader extends Iterator<Object> {
  45   /**
  46    * Gets the next XMLEvent. The initial event is
  47    * {@link javax.xml.stream.events.StartDocument StartDocument}.
  48    *
  49    * @return the next XMLEvent
  50    * @see XMLEvent
  51    * @throws XMLStreamException if there is an error with the underlying XML.
  52    * @throws java.util.NoSuchElementException iteration has no more elements.
  53    */
  54   public XMLEvent nextEvent() throws XMLStreamException;
  55 
  56   /**
  57    * Check if there are more events.
  58    * Returns true if there are more events and false otherwise.
  59    * @return true if the event reader has more events, false otherwise
  60    */
  61   @Override
  62   public boolean hasNext();
  63 
  64   /**
  65    * Check the next XMLEvent without reading it from the stream.
  66    * Returns null if the stream is at EOF or has no more XMLEvents.
  67    * A call to peek() will be equal to the next return of next().
  68    *
  69    * @return the next XMLEvent
  70    * @see XMLEvent
  71    * @throws XMLStreamException
  72    */
  73   public XMLEvent peek() throws XMLStreamException;
  74 
  75   /**
  76    * Reads the content of a text-only element. Precondition:
  77    * the current event is START_ELEMENT. Postcondition:
  78    * The current event is the corresponding END_ELEMENT.
  79    *
  80    * @return the text of the element
  81    * @throws XMLStreamException if the current event is not a START_ELEMENT
  82    * or if a non text element is encountered
  83    */
  84   public String getElementText() throws XMLStreamException;
  85 
  86   /**
  87    * Skips any insignificant space events until a START_ELEMENT or
  88    * END_ELEMENT is reached. If anything other than space characters are
  89    * encountered, an exception is thrown. This method should
  90    * be used when processing element-only content because
  91    * the parser is not able to recognize ignorable whitespace if
  92    * the DTD is missing or not interpreted.
  93    *
  94    * @return a START_ELEMENT or END_ELEMENT
  95    * @throws XMLStreamException if anything other than space characters are encountered
  96    */
  97   public XMLEvent nextTag() throws XMLStreamException;
  98 
  99   /**
 100    * Get the value of a feature/property from the underlying implementation
 101    * @param name The name of the property
 102    * @return The value of the property
 103    * @throws IllegalArgumentException if the property is not supported
 104    */
 105   public Object getProperty(java.lang.String name) throws java.lang.IllegalArgumentException;
 106 
 107   /**
 108    * Frees any resources associated with this Reader.  This method does not close the
 109    * underlying input source.
 110    * @throws XMLStreamException if there are errors freeing associated resources
 111    */
 112   public void close() throws XMLStreamException;
 113 }