Java tutorial
/** * License Agreement for OpenSearchServer * * Copyright (C) 2008-2014 Emmanuel Keller / Jaeksoft * * http://www.open-search-server.com * * This file is part of OpenSearchServer. * * OpenSearchServer is free software: you can redistribute it and/or * modify it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * OpenSearchServer 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with OpenSearchServer. * If not, see <http://www.gnu.org/licenses/>. **/ package com.jaeksoft.searchlib.util; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.util.Map; import java.util.TreeMap; import javax.xml.namespace.QName; import javax.xml.parsers.ParserConfigurationException; import javax.xml.transform.stream.StreamSource; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpression; import javax.xml.xpath.XPathExpressionException; import javax.xml.xpath.XPathFactory; import org.apache.commons.lang.StringEscapeUtils; import org.w3c.dom.Document; import org.w3c.dom.NamedNodeMap; import org.w3c.dom.Node; import org.w3c.dom.NodeList; import org.xml.sax.InputSource; import org.xml.sax.SAXException; public class XPathParser { private final static XPathFactory xPathfactory = XPathFactory.newInstance(); private final XPath xPath; private final Node rootNode; private final File currentFile; private final Map<String, XPathExpression> xPathExpressions; private XPathParser(File currentFile, Node rootNode) { this.xPath = getXPath(); this.currentFile = currentFile; this.rootNode = rootNode; this.xPathExpressions = new TreeMap<String, XPathExpression>(); } public static XPath getXPath() { synchronized (xPathfactory) { return xPathfactory.newXPath(); } } public XPathParser(File file) throws ParserConfigurationException, SAXException, IOException { this(file, DomUtils.readXml(new StreamSource(file.getAbsoluteFile()), true)); } public XPathParser(InputSource inputSource) throws SAXException, IOException, ParserConfigurationException { this(null, DomUtils.readXml(inputSource, true)); Document document = (Document) rootNode; document.normalize(); } public XPathParser(InputStream inputStream) throws SAXException, IOException, ParserConfigurationException { this(null, DomUtils.readXml(new InputSource(inputStream), true)); } public XPathParser(Node rootNode) { this(null, rootNode); } public File getCurrentFile() { return currentFile; } private static final QName[] RETURN_TYPES = { XPathConstants.NODESET, XPathConstants.NODE, XPathConstants.STRING, XPathConstants.NUMBER, XPathConstants.BOOLEAN }; final public static Object evaluate(final Node parentNode, final XPathExpression xPathExpression) throws XPathExpressionException { XPathExpressionException lastError = null; for (QName qname : RETURN_TYPES) { try { Object result = xPathExpression.evaluate(parentNode, qname); if (result != null) return result; } catch (XPathExpressionException e) { lastError = e; } } if (lastError != null) throw lastError; return null; } final public Object evaluate(final Node parentNode, final String query) throws XPathExpressionException { XPathExpression xPathExpression = xPathExpressions.get(query); if (xPathExpression == null) { xPathExpression = xPath.compile(query); xPathExpressions.put(query, xPathExpression); } return evaluate(parentNode, xPathExpression); } public Object evaluate(Node parentNode, String query, QName returnType) throws XPathExpressionException { return xPath.evaluate(query, parentNode, returnType); } public final Node getNode(Node parentNode, String query) throws XPathExpressionException { return (Node) xPath.evaluate(query, parentNode, XPathConstants.NODE); } public final Node getNode(String query) throws XPathExpressionException { return getNode(rootNode, query); } public final String getNodeString(Node parentNode, String query) throws XPathExpressionException { return (String) xPath.evaluate(query, parentNode, XPathConstants.STRING); } public final String getNodeString(String query) throws XPathExpressionException { return getNodeString(rootNode, query); } public final String getNodeString(Node node, boolean trim) throws XPathExpressionException { String txt = xPath.evaluate("text()", node); if (txt == null) return null; return trim ? txt.trim() : txt; } public final NodeList getNodeList(Node parentNode, String query) throws XPathExpressionException { return (NodeList) xPath.evaluate(query, parentNode, XPathConstants.NODESET); } public final NodeList getNodeList(String query) throws XPathExpressionException { return getNodeList(rootNode, query); } public final String getAttributeString(String query, String attributeName) throws XPathExpressionException { Node node = getNode(query); if (node == null) return null; return getAttributeString(node, attributeName); } public final int getAttributeValue(String query, String attributeName) throws XPathExpressionException { Node node = getNode(query); if (node == null) return 0; return getAttributeValue(node, attributeName); } private final static String getAttributeString(Node node, String attributeName, boolean unescapeXml) { NamedNodeMap attr = node.getAttributes(); if (attr == null) return null; Node n = attr.getNamedItem(attributeName); if (n == null) return null; String t = n.getTextContent(); if (t == null) return null; return unescapeXml ? StringEscapeUtils.unescapeXml(t) : t; } public final static boolean getAttributeStringMatch(Node node, String attributeName, String value) { if (value == null) return false; return value.equals(getAttributeString(node, attributeName, true)); } public final static String getAttributeString(Node node, String attributeName) { return getAttributeString(node, attributeName, true); } public final static int getAttributeValue(Node node, String attributeName) { String value = getAttributeString(node, attributeName, false); if (value == null || value.length() == 0) return 0; return Integer.parseInt(value); } public final static long getAttributeLong(Node node, String attributeName) { String value = getAttributeString(node, attributeName, false); if (value == null || value.length() == 0) return 0; return Long.parseLong(value); } public final static Float getAttributeFloat(Node node, String attributeName) { String value = getAttributeString(node, attributeName, false); if (value == null || value.length() == 0) return null; return Float.parseFloat(value); } public final static double getAttributeDouble(Node node, String attributeName) { String value = getAttributeString(node, attributeName, false); if (value == null || value.length() == 0) return 0; return Double.parseDouble(value); } final public String getSubNodeTextIfAny(Node parentNode, String nodeName, boolean trim) throws XPathExpressionException { Node node = getNode(parentNode, nodeName); if (node == null) return null; String txt = node.getTextContent(); if (txt == null) return null; return trim ? txt.trim() : txt; } }