Starting from a node, find the namespace declaration for a prefix. : Namespace « XML « Java Tutorial

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import java.util.List;

import javax.xml.XMLConstants;

import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
 * Few simple utils to read DOM. This is originally from the Jakarta Commons Modeler.
 * @author Costin Manolache
public class Utils {
  private static final String XMLNAMESPACE = "xmlns";
   * Starting from a node, find the namespace declaration for a prefix. for a matching namespace
   * declaration.
   * @param node search up from here to search for namespace definitions
   * @param searchPrefix the prefix we are searching for
   * @return the namespace if found.
  public static String getNamespace(Node node, String searchPrefix) {

      Element el;
      while (!(node instanceof Element)) {
          node = node.getParentNode();
      el = (Element)node;

      NamedNodeMap atts = el.getAttributes();
      for (int i = 0; i < atts.getLength(); i++) {
          Node currentAttribute = atts.item(i);
          String currentLocalName = currentAttribute.getLocalName();
          String currentPrefix = currentAttribute.getPrefix();
          if (searchPrefix.equals(currentLocalName) && XMLNAMESPACE.equals(currentPrefix)) {
              return currentAttribute.getNodeValue();
          } else if (isEmpty(searchPrefix) && XMLNAMESPACE.equals(currentLocalName)
                     && isEmpty(currentPrefix)) {
              return currentAttribute.getNodeValue();

      Node parent = el.getParentNode();
      if (parent instanceof Element) {
          return getNamespace((Element)parent, searchPrefix);

      return null;
  public static boolean isEmpty(String str) {
    return str == null || str.length() == 0;

33.26.1.Access elements from document with namespaces
33.26.2.Handling namespaces during parsing
33.26.3.Create Namespace
33.26.4.Get Attribute by QName
33.26.5.Set a namespace/prefix on an element if it is not set already.
33.26.6.Get all prefixes defined on this element for the specified namespace.
33.26.7.Get all prefixes defined, up to the root, for a namespace URI.
33.26.8.Creates a QName instance from the given namespace context for the given qualifiedName
33.26.9.Starting from a node, find the namespace declaration for a prefix.
33.26.10.Returns the first element that has the specified local name.
33.26.11.Checks whether the supplied String is an NCName (Namespace Classified Name)
33.26.12.Finds and returns the first child node with the given qualified name.
33.26.13.Finds and returns the last child node with the given qualified name.
33.26.14.Finds and returns the next sibling node with the given qualified name.