Here you can find the source of evaluate(Document doc)
private static Node evaluate(Document doc) throws XPathExpressionException
//package com.java2s; /*//from ww w. j a v a2 s . c o m * SonarQube Java * Copyright (C) 2012-2016 SonarSource SA * mailto:contact AT sonarsource DOT com * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ import org.w3c.dom.Document; import org.w3c.dom.Node; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpression; import javax.xml.xpath.XPathExpressionException; public class Main { private static XPathExpression expression; private static Node evaluate(Document doc) throws XPathExpressionException { return (Node) expression.evaluate(doc, XPathConstants.NODE); } }