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1   ////////////////////////////////////////////////////////////////////////////////
2   // checkstyle: Checks Java source code for adherence to a set of rules.
3   // Copyright (C) 2001-2017 the original author or authors.
4   //
5   // This library is free software; you can redistribute it and/or
6   // modify it under the terms of the GNU Lesser General Public
7   // License as published by the Free Software Foundation; either
8   // version 2.1 of the License, or (at your option) any later version.
9   //
10  // This library is distributed in the hope that it will be useful,
11  // but WITHOUT ANY WARRANTY; without even the implied warranty of
12  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  // Lesser General Public License for more details.
14  //
15  // You should have received a copy of the GNU Lesser General Public
16  // License along with this library; if not, write to the Free Software
17  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  ////////////////////////////////////////////////////////////////////////////////
19  
20  package com.puppycrawl.tools.checkstyle.internal.utils;
21  
22  import java.util.List;
23  
24  import com.puppycrawl.tools.checkstyle.xpath.AbstractNode;
25  import net.sf.saxon.om.Item;
26  import net.sf.saxon.sxpath.XPathDynamicContext;
27  import net.sf.saxon.sxpath.XPathEvaluator;
28  import net.sf.saxon.sxpath.XPathExpression;
29  import net.sf.saxon.trans.XPathException;
30  
31  /**
32   * XpathUtil.
33   * @noinspection ClassOnlyUsedInOnePackage
34   */
35  public final class XpathUtil {
36      private XpathUtil() {
37      }
38  
39      /**
40       * Returns list of nodes matching xpath expression given node context.
41       * @param xpath Xpath expression
42       * @param rootNode {@code NodeInfo} node context
43       * @return list of nodes matching xpath expression given node context
44       */
45      public static List<Item> getXpathItems(String xpath, AbstractNode rootNode)
46              throws XPathException {
47          final XPathEvaluator xpathEvaluator = new XPathEvaluator();
48          final XPathExpression xpathExpression = xpathEvaluator.createExpression(xpath);
49          final XPathDynamicContext xpathDynamicContext = xpathExpression
50                  .createDynamicContext(rootNode);
51          return xpathExpression.evaluate(xpathDynamicContext);
52      }
53  }