com.hp.hpl.sparta

Class Document

java.lang.Object

com.hp.hpl.sparta.Node

com.hp.hpl.sparta.Document

public class Document
extends Node

An XML Document.

Copyright (C) 2002 Hewlett-Packard Company. This file is part of Sparta, an XML Parser, DOM, and XPath library. This library 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 library 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.

Version:

$Date: 2003/11/01 05:42:18 $ $Revision: 1.12 $

Author:

Eamonn O'Brien-Strain

See Also:

GNU Lesser General Public License, Document

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	Document.Index
static interface	Document.Observer Something that is informed whenever the document changes.

Constructor Summary

Constructors

Constructor and Description
Document() Create new empty in-memory Document with a null documentElement.

Method Summary

Methods

Modifier and Type	Method and Description
void	addObserver(Document.Observer observer)
Object	clone() Deep copy of this document.
protected int	computeHashCode() Called whenever cached version of hashCode needs to be regenerated.
void	deleteObserver(Document.Observer observer)
boolean	equals(Object thatO) Two documents are equal IFF their document elements are equal.
Element	getDocumentElement()
String	getSystemId()
void	setDocumentElement(Element rootElement) Set the root element of this DOM tree.
void	setSystemId(String systemId)
String	toString() Same as getSystemId
void	toString(Writer writer) Accumulate text nodes hierarchically.
void	toXml(Writer writer) Write DOM to XML.
boolean	xpathEnsure(String xpath) Just like Element.xpathEnsure, but also handles case of no documentElement.
Document.Index	xpathGetIndex(String xpath) For faster lookup by XPath return (creating if necessary) an index.
boolean	xpathHasIndex(String xpath)
Element	xpathSelectElement(String xpath) Select the first element that matches the absolute XPath expression in this document, or null if there is no match.
Enumeration	xpathSelectElements(String xpath) Select all the elements that match the absolute XPath expression in this document.
String	xpathSelectString(String xpath) Select the first element that matches the absolute XPath expression in this document, or null if there is no match.
Enumeration	xpathSelectStrings(String xpath) Select all the strings that match the absolute XPath expression in this document.

Methods inherited from class com.hp.hpl.sparta.Node

getAnnotation, getNextSibling, getOwnerDocument, getParentNode, getPreviousSibling, hashCode, htmlEncode, setAnnotation, toXml, xpathSetStrings

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Document

public Document()

Create new empty in-memory Document with a null documentElement.

Method Detail

clone

public Object clone()

Deep copy of this document. Any annotation is not copied.

Specified by:

clone in class Node

getSystemId

public String getSystemId()

Returns:

the filename, URL, or other ID by which this document is known. Initialized to "MEMORY" for Document created with default constructor.

setSystemId

public void setSystemId(String systemId)

Parameters:

systemId - the filename, URL, or other ID by which this document is known.

toString

public String toString()

Same as getSystemId

Overrides:

toString in class Node

getDocumentElement

public Element getDocumentElement()

Returns:

root element of this DOM tree.

setDocumentElement

public void setDocumentElement(Element rootElement)

Set the root element of this DOM tree.

xpathSelectElements

public Enumeration xpathSelectElements(String xpath)
                                throws ParseException

Select all the elements that match the absolute XPath expression in this document.

Specified by:

xpathSelectElements in class Node

Throws:

ParseException

xpathSelectStrings

public Enumeration xpathSelectStrings(String xpath)
                               throws ParseException

Select all the strings that match the absolute XPath expression in this document.

Specified by:

xpathSelectStrings in class Node

Throws:

ParseException

xpathSelectElement

public Element xpathSelectElement(String xpath)
                           throws ParseException

Select the first element that matches the absolute XPath expression in this document, or null if there is no match.

Specified by:

xpathSelectElement in class Node

Throws:

ParseException

xpathSelectString

public String xpathSelectString(String xpath)
                         throws ParseException

Select the first element that matches the absolute XPath expression in this document, or null if there is no match.

Specified by:

xpathSelectString in class Node

Throws:

ParseException

xpathEnsure

public boolean xpathEnsure(String xpath)
                    throws ParseException

Just like Element.xpathEnsure, but also handles case of no documentElement.

Throws:

ParseException

xpathHasIndex

public boolean xpathHasIndex(String xpath)

Returns:

whether an index existst for this xpath

See Also:

xpathGetIndex(java.lang.String)

xpathGetIndex

public Document.Index xpathGetIndex(String xpath)
                             throws ParseException

For faster lookup by XPath return (creating if necessary) an index. The xpath should be of the form "xp[@attrName]" where xp is an xpath, not ending in a "[...]" predicate, that returns a list of elements. Doing a get("foo") on the index is equivalent to doing an xpathSelectElement("xp[@attrName='foo']") on the document except that it is faster ( O(1) as apposed to O(n) ). EXAMPLE:

   Enumeration leaders;
   if( doc.xpathHasIndex( "/Team/Members[@firstName]" ){
     //fast version
     Document.Index index = doc.xpathGetIndex( "/Team/Members[@role]" );
     leaders = index.get("leader");
   }else
     //slow version
     leaders = doc.xpathSelectElement( "/Team/Members[@role='leader']" );

Throws:

ParseException

addObserver

public void addObserver(Document.Observer observer)

deleteObserver

public void deleteObserver(Document.Observer observer)

toString

public void toString(Writer writer)
              throws IOException

Accumulate text nodes hierarchically.

Throws:

IOException

toXml

public void toXml(Writer writer)
           throws IOException

Write DOM to XML.

Throws:

IOException

equals

public boolean equals(Object thatO)

Two documents are equal IFF their document elements are equal.

Overrides:

equals in class Object

computeHashCode

protected int computeHashCode()

Called whenever cached version of hashCode needs to be regenerated.

Specified by:

computeHashCode in class Node