org.apache.xml.resolver.helpers.Namespaces Maven / Gradle / Ivy
// Namespaces.java - Analyze namespace nodes in a DOM tree
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.xml.resolver.helpers;
import org.w3c.dom.*;
/**
* Static Namespace query methods.
*
* This class defines a set of static methods that can be called
* to analyze the namespace properties of DOM nodes.
*
* @author Norman Walsh
* [email protected]
*
* @version 1.0
*/
public class Namespaces {
/**
* Returns the "prefix" part of a QName or the empty string (not
* null) if the name has no prefix.
*
* @param element The QName of an element.
* @return The prefix part of the element name.
*/
public static String getPrefix(Element element) {
String name = element.getTagName();
String prefix = "";
if (name.indexOf(':') > 0) {
prefix = name.substring(0, name.indexOf(':'));
}
return prefix;
}
/**
* Returns the "localname" part of a QName, which is the whole
* name if it has no prefix.
*
* @param element The QName of an element.
* @return The local part of a QName.
*/
public static String getLocalName(Element element) {
String name = element.getTagName();
if (name.indexOf(':') > 0) {
name = name.substring(name.indexOf(':')+1);
}
return name;
}
/**
* Returns the namespace URI for the specified prefix at the
* specified context node.
*
* @param node The context node.
* @param prefix The prefix.
* @return The namespace URI associated with the prefix, or
* null if no namespace declaration exists for the prefix.
*/
public static String getNamespaceURI(Node node, String prefix) {
if (node == null || node.getNodeType() != Node.ELEMENT_NODE) {
return null;
}
if (prefix.equals("")) {
if (((Element) node).hasAttribute("xmlns")) {
return ((Element) node).getAttribute("xmlns");
}
} else {
String nsattr = "xmlns:" + prefix;
if (((Element) node).hasAttribute(nsattr)) {
return ((Element) node).getAttribute(nsattr);
}
}
return getNamespaceURI(node.getParentNode(), prefix);
}
/**
* Returns the namespace URI for the namespace to which the
* element belongs.
*
* @param element The element.
* @return The namespace URI associated with the namespace of the
* element, or null if no namespace declaration exists for it.
*/
public static String getNamespaceURI(Element element) {
String prefix = getPrefix(element);
return getNamespaceURI(element, prefix);
}
}