org.apache.jcp.xml.dsig.internal.dom
Class DOMUtils

java.lang.Object
  org.apache.jcp.xml.dsig.internal.dom.DOMUtils

public class DOMUtils
extends Object

Useful static DOM utility methods.

Author:

Sean Mullan

Method Summary

static void	appendChild(Node parent, Node child) Checks if child element has same owner document before appending to the parent, and imports it to the parent's document if necessary.
static Element	createElement(Document doc, String tag, String nsURI, String prefix) Creates an element in the specified namespace, with the specified tag and namespace prefix.
static String	getAttributeValue(Element elem, String name) Returns the attribute value for the attribute with the specified name.
static Element	getFirstChildElement(Node node) Returns the first child element of the specified node, or null if there is no such element.
static <N> String	getIdAttributeValue(Element elem, String name) Returns the attribute value for the attribute with the specified name.
static Element	getLastChildElement(Node node) Returns the last child element of the specified node, or null if there is no such element.
static Element	getNextSiblingElement(Node node) Returns the next sibling element of the specified node, or null if there is no such element.
static String	getNSPrefix(XMLCryptoContext context, String nsURI) Returns the prefix associated with the specified namespace URI
static Document	getOwnerDocument(Node node) Returns the owner document of the specified node.
static String	getQNameString(String prefix, String localName) Create a QName string from a prefix and local name.
static String	getSignaturePrefix(XMLCryptoContext context) Returns the prefix associated with the XML Signature namespace URI
static boolean	isNamespace(Node node)
static boolean	nodesEqual(Node thisNode, Node otherNode) Compares 2 nodes for equality.
static Set<Node>	nodeSet(NodeList nl) Returns a Set of Nodes, backed by the specified NodeList.
static boolean	paramsEqual(AlgorithmParameterSpec spec1, AlgorithmParameterSpec spec2)
static void	removeAllChildren(Node node) Removes all children nodes from the specified node.
static void	setAttribute(Element elem, String name, String value) Sets an element's attribute (using DOM level 2) with the specified value and namespace prefix.
static void	setAttributeID(Element elem, String name, String value) Sets an element's attribute (using DOM level 2) with the specified value and namespace prefix AND registers the ID value with the specified element.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getOwnerDocument

public static Document getOwnerDocument(Node node)

Returns the owner document of the specified node.

Parameters:

node - the node

Returns:

the owner document

getQNameString

public static String getQNameString(String prefix,
                                    String localName)

Create a QName string from a prefix and local name.

Parameters:

prefix - The prefix, if any. Can be either null or empty.

localName - The local name.

Returns:

The string for the qName, for example, "xsd:element".

createElement

public static Element createElement(Document doc,
                                    String tag,
                                    String nsURI,
                                    String prefix)

Creates an element in the specified namespace, with the specified tag and namespace prefix.

Parameters:

doc - the owner document

tag - the tag

nsURI - the namespace URI

prefix - the namespace prefix

Returns:

the newly created element

setAttribute

public static void setAttribute(Element elem,
                                String name,
                                String value)

Sets an element's attribute (using DOM level 2) with the specified value and namespace prefix.

Parameters:

elem - the element to set the attribute on

name - the name of the attribute

value - the attribute value. If null, no attribute is set.

setAttributeID

public static void setAttributeID(Element elem,
                                  String name,
                                  String value)

Sets an element's attribute (using DOM level 2) with the specified value and namespace prefix AND registers the ID value with the specified element. This is for resolving same-document ID references.

Parameters:

elem - the element to set the attribute on

name - the name of the attribute

value - the attribute value. If null, no attribute is set.

getFirstChildElement

public static Element getFirstChildElement(Node node)

Returns the first child element of the specified node, or null if there is no such element.

Parameters:

node - the node

Returns:

the first child element of the specified node, or null if there is no such element

Throws:

NullPointerException - if node == null

getLastChildElement

public static Element getLastChildElement(Node node)

Returns the last child element of the specified node, or null if there is no such element.

Parameters:

node - the node

Returns:

the last child element of the specified node, or null if there is no such element

Throws:

NullPointerException - if node == null

getNextSiblingElement

public static Element getNextSiblingElement(Node node)

Returns the next sibling element of the specified node, or null if there is no such element.

Parameters:

node - the node

Returns:

the next sibling element of the specified node, or null if there is no such element

Throws:

NullPointerException - if node == null

getAttributeValue

public static String getAttributeValue(Element elem,
                                       String name)

Returns the attribute value for the attribute with the specified name. Returns null if there is no such attribute, or the empty string if the attribute value is empty.

This works around a limitation of the DOM Element.getAttributeNode method, which does not distinguish between an unspecified attribute and an attribute with a value of "" (it returns "" for both cases).

Parameters:

elem - the element containing the attribute

name - the name of the attribute

Returns:

the attribute value (may be null if unspecified)

getIdAttributeValue

public static <N> String getIdAttributeValue(Element elem,
                                             String name)

Returns the attribute value for the attribute with the specified name. Returns null if there is no such attribute, or the empty string if the attribute value is empty.

This works around a limitation of the DOM Element.getAttributeNode method, which does not distinguish between an unspecified attribute and an attribute with a value of "" (it returns "" for both cases).

Parameters:

elem - the element containing the attribute

name - the name of the attribute

Returns:

the attribute value (may be null if unspecified)

nodeSet

public static Set<Node> nodeSet(NodeList nl)

Returns a Set of Nodes, backed by the specified NodeList.

Parameters:

nl - the NodeList

Returns:

a Set of Nodes

getNSPrefix

public static String getNSPrefix(XMLCryptoContext context,
                                 String nsURI)

Returns the prefix associated with the specified namespace URI

Parameters:

context - contains the namespace map

nsURI - the namespace URI

Returns:

the prefix associated with the specified namespace URI, or null if not set

getSignaturePrefix

public static String getSignaturePrefix(XMLCryptoContext context)

Returns the prefix associated with the XML Signature namespace URI

Parameters:

context - contains the namespace map

Returns:

the prefix associated with the specified namespace URI, or null if not set

removeAllChildren

public static void removeAllChildren(Node node)

Removes all children nodes from the specified node.

Parameters:

node - the parent node whose children are to be removed

nodesEqual

public static boolean nodesEqual(Node thisNode,
                                 Node otherNode)

Compares 2 nodes for equality. Implementation is not complete.

appendChild

public static void appendChild(Node parent,
                               Node child)

Checks if child element has same owner document before appending to the parent, and imports it to the parent's document if necessary.

paramsEqual

public static boolean paramsEqual(AlgorithmParameterSpec spec1,
                                  AlgorithmParameterSpec spec2)

isNamespace

public static boolean isNamespace(Node node)