import com.sun.org.apache.xml.internal.utils.DOMHelper; //导入依赖的package包/类
/**
 * The set:leading function returns the nodes in the node set passed as the first argument that
 * precede, in document order, the first node in the node set passed as the second argument. If
 * the first node in the second node set is not contained in the first node set, then an empty
 * node set is returned. If the second node set is empty, then the first node set is returned.
 *
 * @param nl1 NodeList for first node-set.
 * @param nl2 NodeList for second node-set.
 * @return a NodeList containing the nodes in nl1 that precede in document order the first
 * node in nl2; an empty node-set if the first node in nl2 is not in nl1; all of nl1 if nl2
 * is empty.
 *
 * @see <a href="http://www.exslt.org/">EXSLT</a>
 */
public static NodeList leading (NodeList nl1, NodeList nl2)
{
  if (nl2.getLength() == 0)
    return nl1;

  NodeSet ns1 = new NodeSet(nl1);
  NodeSet leadNodes = new NodeSet();
  Node endNode = nl2.item(0);
  if (!ns1.contains(endNode))
    return leadNodes; // empty NodeSet

  for (int i = 0; i < nl1.getLength(); i++)
  {
    Node testNode = nl1.item(i);
    if (DOMHelper.isNodeAfter(testNode, endNode)
        && !DOMHelper.isNodeTheSame(testNode, endNode))
      leadNodes.addElement(testNode);
  }
  return leadNodes;
}
 

import com.sun.org.apache.xml.internal.utils.DOMHelper; //导入依赖的package包/类
/**
 * The set:trailing function returns the nodes in the node set passed as the first argument that
 * follow, in document order, the first node in the node set passed as the second argument. If
 * the first node in the second node set is not contained in the first node set, then an empty
 * node set is returned. If the second node set is empty, then the first node set is returned.
 *
 * @param nl1 NodeList for first node-set.
 * @param nl2 NodeList for second node-set.
 * @return a NodeList containing the nodes in nl1 that follow in document order the first
 * node in nl2; an empty node-set if the first node in nl2 is not in nl1; all of nl1 if nl2
 * is empty.
 *
 * @see <a href="http://www.exslt.org/">EXSLT</a>
 */
public static NodeList trailing (NodeList nl1, NodeList nl2)
{
  if (nl2.getLength() == 0)
    return nl1;

  NodeSet ns1 = new NodeSet(nl1);
  NodeSet trailNodes = new NodeSet();
  Node startNode = nl2.item(0);
  if (!ns1.contains(startNode))
    return trailNodes; // empty NodeSet

  for (int i = 0; i < nl1.getLength(); i++)
  {
    Node testNode = nl1.item(i);
    if (DOMHelper.isNodeAfter(startNode, testNode)
        && !DOMHelper.isNodeTheSame(startNode, testNode))
      trailNodes.addElement(testNode);
  }
  return trailNodes;
}