http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
/*
 * Copyright (c) 2004 World Wide Web Consortium,
 *
 * (Massachusetts Institute of Technology, European Research Consortium for
 * Informatics and Mathematics, Keio University). All Rights Reserved. This
 * work is distributed under the W3C(r) Software License [1] 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.
 *
 * [1] http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
 */

package org.w3c.dom.xpath;

import org.w3c.dom.Node;
import org.w3c.dom.DOMException;


The XPathResult interface represents the result of the 
evaluation of an XPath 1.0 expression within the context of a particular 
node. Since evaluation of an XPath expression can result in various 
result types, this object makes it possible to discover and manipulate 
the type and value of the result.

See also the Document Object Model (DOM) Level 3 XPath Specification.

/**
 * The <code>XPathResult</code> interface represents the result of the 
 * evaluation of an XPath 1.0 expression within the context of a particular 
 * node. Since evaluation of an XPath expression can result in various 
 * result types, this object makes it possible to discover and manipulate 
 * the type and value of the result.
 * <p>See also the <a href='http://www.w3.org/TR/2004/NOTE-DOM-Level-3-XPath-20040226'>Document Object Model (DOM) Level 3 XPath Specification</a>.
 */
public interface XPathResult {
    // XPathResultType
    
This code does not represent a specific type. An evaluation of an XPath 
expression will never produce this type. If this type is requested, 
then the evaluation returns whatever type naturally results from 
evaluation of the expression. 

If the natural result is a node set when ANY_TYPE was 
requested, then UNORDERED_NODE_ITERATOR_TYPE is always 
the resulting type. Any other representation of a node set must be 
explicitly requested.

/**
     * This code does not represent a specific type. An evaluation of an XPath 
     * expression will never produce this type. If this type is requested, 
     * then the evaluation returns whatever type naturally results from 
     * evaluation of the expression. 
     * <br>If the natural result is a node set when <code>ANY_TYPE</code> was 
     * requested, then <code>UNORDERED_NODE_ITERATOR_TYPE</code> is always 
     * the resulting type. Any other representation of a node set must be 
     * explicitly requested.
     */
    public static final short ANY_TYPE                  = 0;
    
The result is a number as defined by [XPath 1.0]. 
Document modification does not invalidate the number, but may mean 
that reevaluation would not yield the same number.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#numbers'>number</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>]. 
     * Document modification does not invalidate the number, but may mean 
     * that reevaluation would not yield the same number.
     */
    public static final short NUMBER_TYPE               = 1;
    
The result is a string as defined by [XPath 1.0]. 
Document modification does not invalidate the string, but may mean 
that the string no longer corresponds to the current document.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#strings'>string</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>]. 
     * Document modification does not invalidate the string, but may mean 
     * that the string no longer corresponds to the current document.
     */
    public static final short STRING_TYPE               = 2;
    
The result is a boolean as defined by [XPath 1.0]. 
Document modification does not invalidate the boolean, but may mean 
that reevaluation would not yield the same boolean.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#booleans'>boolean</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>]. 
     * Document modification does not invalidate the boolean, but may mean 
     * that reevaluation would not yield the same boolean.
     */
    public static final short BOOLEAN_TYPE              = 3;
    
The result is a node set as defined by [XPath 1.0] that 
will be accessed iteratively, which may not produce nodes in a 
particular order. Document modification invalidates the iteration.

This is the default type returned if the result is a node set and 
ANY_TYPE is requested.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that 
     * will be accessed iteratively, which may not produce nodes in a 
     * particular order. Document modification invalidates the iteration.
     * <br>This is the default type returned if the result is a node set and 
     * <code>ANY_TYPE</code> is requested.
     */
    public static final short UNORDERED_NODE_ITERATOR_TYPE = 4;
    
The result is a node set as defined by [XPath 1.0] that 
will be accessed iteratively, which will produce document-ordered 
nodes. Document modification invalidates the iteration.

/**
     * The result is a node set as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that 
     * will be accessed iteratively, which will produce document-ordered 
     * nodes. Document modification invalidates the iteration.
     */
    public static final short ORDERED_NODE_ITERATOR_TYPE = 5;
    
The result is a node set as defined by [XPath 1.0] that 
will be accessed as a snapshot list of nodes that may not be in a 
particular order. Document modification does not invalidate the 
snapshot but may mean that reevaluation would not yield the same 
snapshot and nodes in the snapshot may have been altered, moved, or 
removed from the document.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that 
     * will be accessed as a snapshot list of nodes that may not be in a 
     * particular order. Document modification does not invalidate the 
     * snapshot but may mean that reevaluation would not yield the same 
     * snapshot and nodes in the snapshot may have been altered, moved, or 
     * removed from the document.
     */
    public static final short UNORDERED_NODE_SNAPSHOT_TYPE = 6;
    
The result is a node set as defined by [XPath 1.0] that 
will be accessed as a snapshot list of nodes that will be in original 
document order. Document modification does not invalidate the 
snapshot but may mean that reevaluation would not yield the same 
snapshot and nodes in the snapshot may have been altered, moved, or 
removed from the document.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] that 
     * will be accessed as a snapshot list of nodes that will be in original 
     * document order. Document modification does not invalidate the 
     * snapshot but may mean that reevaluation would not yield the same 
     * snapshot and nodes in the snapshot may have been altered, moved, or 
     * removed from the document.
     */
    public static final short ORDERED_NODE_SNAPSHOT_TYPE = 7;
    
The result is a node set as defined by [XPath 1.0] and 
will be accessed as a single node, which may be nullif 
the node set is empty. Document modification does not invalidate the 
node, but may mean that the result node no longer corresponds to the 
current document. This is a convenience that permits optimization 
since the implementation can stop once any node in the resulting set 
has been found.

If there is more than one node in the actual result, the single 
node returned might not be the first in document order.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] and 
     * will be accessed as a single node, which may be <code>null</code>if 
     * the node set is empty. Document modification does not invalidate the 
     * node, but may mean that the result node no longer corresponds to the 
     * current document. This is a convenience that permits optimization 
     * since the implementation can stop once any node in the resulting set 
     * has been found.
     * <br>If there is more than one node in the actual result, the single 
     * node returned might not be the first in document order.
     */
    public static final short ANY_UNORDERED_NODE_TYPE   = 8;
    
The result is a node set as defined by [XPath 1.0] and 
will be accessed as a single node, which may be null if 
the node set is empty. Document modification does not invalidate the 
node, but may mean that the result node no longer corresponds to the 
current document. This is a convenience that permits optimization 
since the implementation can stop once the first node in document 
order of the resulting set has been found.

If there are more than one node in the actual result, the single 
node returned will be the first in document order.

/**
     * The result is a <a href='http://www.w3.org/TR/1999/REC-xpath-19991116#node-sets'>node set</a> as defined by [<a href='http://www.w3.org/TR/1999/REC-xpath-19991116'>XPath 1.0</a>] and 
     * will be accessed as a single node, which may be <code>null</code> if 
     * the node set is empty. Document modification does not invalidate the 
     * node, but may mean that the result node no longer corresponds to the 
     * current document. This is a convenience that permits optimization 
     * since the implementation can stop once the first node in document 
     * order of the resulting set has been found.
     * <br>If there are more than one node in the actual result, the single 
     * node returned will be the first in document order.
     */
    public static final short FIRST_ORDERED_NODE_TYPE   = 9;

    
A code representing the type of this result, as defined by the type 
constants.

/**
     * A code representing the type of this result, as defined by the type 
     * constants.
     */
    public short getResultType();

    
The value of this number result. If the native double type of the DOM 
binding does not directly support the exact IEEE 754 result of the 
XPath expression, then it is up to the definition of the binding to 
specify how the XPath number is converted to the native binding 
number.

Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  NUMBER_TYPE.
/**
     * The value of this number result. If the native double type of the DOM 
     * binding does not directly support the exact IEEE 754 result of the 
     * XPath expression, then it is up to the definition of the binding to 
     * specify how the XPath number is converted to the native binding 
     * number.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>NUMBER_TYPE</code>.
     */
    public double getNumberValue()
                             throws XPathException;

    
The value of this string result.

Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  STRING_TYPE.
/**
     * The value of this string result.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>STRING_TYPE</code>.
     */
    public String getStringValue()
                             throws XPathException;

    
The value of this boolean result.

Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  BOOLEAN_TYPE.
/**
     * The value of this boolean result.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>BOOLEAN_TYPE</code>.
     */
    public boolean getBooleanValue()
                             throws XPathException;

    
The value of this single node result, which may be null.

Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  ANY_UNORDERED_NODE_TYPE or 
  FIRST_ORDERED_NODE_TYPE.
/**
     * The value of this single node result, which may be <code>null</code>.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>ANY_UNORDERED_NODE_TYPE</code> or 
     *   <code>FIRST_ORDERED_NODE_TYPE</code>.
     */
    public Node getSingleNodeValue()
                             throws XPathException;

    
Signifies that the iterator has become invalid. True if 
resultType is UNORDERED_NODE_ITERATOR_TYPE 
or ORDERED_NODE_ITERATOR_TYPE and the document has been 
modified since this result was returned.

/**
     * Signifies that the iterator has become invalid. True if 
     * <code>resultType</code> is <code>UNORDERED_NODE_ITERATOR_TYPE</code> 
     * or <code>ORDERED_NODE_ITERATOR_TYPE</code> and the document has been 
     * modified since this result was returned.
     */
    public boolean getInvalidIteratorState();

    
The number of nodes in the result snapshot. Valid values for 
snapshotItem indices are 0 to 
snapshotLength-1 inclusive.

Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  UNORDERED_NODE_SNAPSHOT_TYPE or 
  ORDERED_NODE_SNAPSHOT_TYPE.
/**
     * The number of nodes in the result snapshot. Valid values for 
     * snapshotItem indices are <code>0</code> to 
     * <code>snapshotLength-1</code> inclusive.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or 
     *   <code>ORDERED_NODE_SNAPSHOT_TYPE</code>.
     */
    public int getSnapshotLength()
                             throws XPathException;

    
Iterates and returns the next node from the node set or 
nullif there are no more nodes.

Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  UNORDERED_NODE_ITERATOR_TYPE or 
  ORDERED_NODE_ITERATOR_TYPE.
  • DOMException – 
  INVALID_STATE_ERR: The document has been mutated since the result was 
  returned.
Returns:Returns the next node.
/**
     * Iterates and returns the next node from the node set or 
     * <code>null</code>if there are no more nodes.
     * @return Returns the next node.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>UNORDERED_NODE_ITERATOR_TYPE</code> or 
     *   <code>ORDERED_NODE_ITERATOR_TYPE</code>.
     * @exception DOMException
     *   INVALID_STATE_ERR: The document has been mutated since the result was 
     *   returned.
     */
    public Node iterateNext()
                            throws XPathException, DOMException;

    
Returns the indexth item in the snapshot collection. If 
index is greater than or equal to the number of nodes in 
the list, this method returns null. Unlike the iterator 
result, the snapshot does not become invalid, but may not correspond 
to the current document if it is mutated.

Params:
  • index – Index into the snapshot collection.
Throws:
  • XPathException – 
  TYPE_ERR: raised if resultType is not 
  UNORDERED_NODE_SNAPSHOT_TYPE or 
  ORDERED_NODE_SNAPSHOT_TYPE.
Returns:The node at the indexth position in the 
  NodeList, or null if that is not a valid 
  index.
/**
     * Returns the <code>index</code>th item in the snapshot collection. If 
     * <code>index</code> is greater than or equal to the number of nodes in 
     * the list, this method returns <code>null</code>. Unlike the iterator 
     * result, the snapshot does not become invalid, but may not correspond 
     * to the current document if it is mutated.
     * @param index Index into the snapshot collection.
     * @return The node at the <code>index</code>th position in the 
     *   <code>NodeList</code>, or <code>null</code> if that is not a valid 
     *   index.
     * @exception XPathException
     *   TYPE_ERR: raised if <code>resultType</code> is not 
     *   <code>UNORDERED_NODE_SNAPSHOT_TYPE</code> or 
     *   <code>ORDERED_NODE_SNAPSHOT_TYPE</code>.
     */
    public Node snapshotItem(int index)
                             throws XPathException;

}