Compare two DOM Nodes from JBoss : Node « XML « Java Tutorial

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2. XML
3. Node

/**
 * JBoss, Home of Professional Open Source
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */

import java.util.ArrayList;
import java.util.List;

import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * @author <a href="mailto:ovidiu@feodorov.com">Ovidiu Feodorov</a>
 * @version <tt>$Revision: 3282 $</tt> $Id: XMLUtil.java 3282 2007-11-01
 *          15:32:29Z timfox $
 */
public class Utils {

  public static void assertEquivalent(Node node, Node node2) {
    if (node == null) {
      throw new IllegalArgumentException("the first node to be compared is null");
    }

    if (node2 == null) {
      throw new IllegalArgumentException("the second node to be compared is null");
    }

    if (!node.getNodeName().equals(node2.getNodeName())) {
      throw new IllegalArgumentException("nodes have different node names");
    }

    int attrCount = 0;
    NamedNodeMap attrs = node.getAttributes();
    if (attrs != null) {
      attrCount = attrs.getLength();
    }

    int attrCount2 = 0;
    NamedNodeMap attrs2 = node2.getAttributes();
    if (attrs2 != null) {
      attrCount2 = attrs2.getLength();
    }

    if (attrCount != attrCount2) {
      throw new IllegalArgumentException("nodes hava a different number of attributes");
    }

    outer: for (int i = 0; i < attrCount; i++) {
      Node n = attrs.item(i);
      String name = n.getNodeName();
      String value = n.getNodeValue();

      for (int j = 0; j < attrCount; j++) {
        Node n2 = attrs2.item(j);
        String name2 = n2.getNodeName();
        String value2 = n2.getNodeValue();

        if (name.equals(name2) && value.equals(value2)) {
          continue outer;
        }
      }
      throw new IllegalArgumentException("attribute " + name + "=" + value + " doesn't match");
    }

    boolean hasChildren = node.hasChildNodes();

    if (hasChildren != node2.hasChildNodes()) {
      throw new IllegalArgumentException("one node has children and the other doesn't");
    }

    if (hasChildren) {
      NodeList nl = node.getChildNodes();
      NodeList nl2 = node2.getChildNodes();

      short[] toFilter = new short[] { Node.TEXT_NODE, Node.ATTRIBUTE_NODE, Node.COMMENT_NODE };
      List nodes = filter(nl, toFilter);
      List nodes2 = filter(nl2, toFilter);

      int length = nodes.size();

      if (length != nodes2.size()) {
        throw new IllegalArgumentException("nodes hava a different number of children");
      }

      for (int i = 0; i < length; i++) {
        Node n = (Node) nodes.get(i);
        Node n2 = (Node) nodes2.get(i);
        assertEquivalent(n, n2);
      }
    }
  }

  private static List filter(NodeList nl, short[] typesToFilter) {
    List nodes = new ArrayList();

    outer: for (int i = 0; i < nl.getLength(); i++) {
      Node n = nl.item(i);
      short type = n.getNodeType();
      for (int j = 0; j < typesToFilter.length; j++) {
        if (typesToFilter[j] == type) {
          continue outer;
        }
      }
      nodes.add(n);
    }
    return nodes;
  }
}