| /* |
| Licensed to the Apache Software Foundation (ASF) under one |
| or more contributor license agreements. See the NOTICE file |
| distributed with this work for additional information |
| regarding copyright ownership. The ASF licenses this file |
| to you under the Apache License, Version 2.0 (the |
| "License"); you may not use this file except in compliance |
| with the License. You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, |
| software distributed under the License is distributed on an |
| "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| KIND, either express or implied. See the License for the |
| specific language governing permissions and limitations |
| under the License. |
| */ |
| |
| package org.apache.wiki.util; |
| |
| import org.apache.commons.lang3.StringUtils; |
| import org.apache.log4j.Logger; |
| import org.jdom2.Document; |
| import org.jdom2.Element; |
| import org.jdom2.JDOMException; |
| import org.jdom2.filter.Filters; |
| import org.jdom2.input.SAXBuilder; |
| import org.jdom2.xpath.XPathExpression; |
| import org.jdom2.xpath.XPathFactory; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.net.URL; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Enumeration; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * Utility class to parse XML files. |
| * <p> |
| * This uses JDOM2 as its backing implementation. |
| * </p> |
| * |
| * @since 2.10 |
| */ |
| public final class XmlUtil { |
| |
| private static final Logger log = Logger.getLogger( XmlUtil.class ); |
| private XmlUtil() {} |
| |
| /** |
| * Parses the given XML file and returns the requested nodes. If there's an error accessing or parsing the file, an |
| * empty list is returned. |
| * |
| * @param xml file to parse; matches all resources from classpath, filters repeated items. |
| * @param requestedNodes requestd nodes on the xml file |
| * @return the requested nodes of the XML file. |
| */ |
| public static List<Element> parse( String xml, String requestedNodes ) |
| { |
| if( StringUtils.isNotEmpty( xml ) && StringUtils.isNotEmpty( requestedNodes ) ) { |
| Set<Element> readed = new HashSet<Element>(); |
| SAXBuilder builder = new SAXBuilder(); |
| try { |
| Enumeration< URL > resources = XmlUtil.class.getClassLoader().getResources( xml ); |
| while( resources.hasMoreElements() ) { |
| URL resource = resources.nextElement(); |
| log.debug( "reading " + resource.toString() ); |
| Document doc = builder.build( resource ); |
| XPathFactory xpfac = XPathFactory.instance(); |
| XPathExpression<Element> xp = xpfac.compile( requestedNodes, Filters.element() ); |
| readed.addAll( xp.evaluate( doc ) ); // filter out repeated items |
| } |
| return new ArrayList<Element>( readed ); |
| } catch ( IOException ioe ) { |
| log.error( "Couldn't load all " + xml + " resources", ioe ); |
| } catch ( JDOMException jdome ) { |
| log.error( "error parsing " + xml + " resources", jdome ); |
| } |
| } |
| return Collections.emptyList(); |
| } |
| |
| /** |
| * Parses the given stream and returns the requested nodes. If there's an error accessing or parsing the stream, an |
| * empty list is returned. |
| * |
| * @param xmlStream stream to parse. |
| * @param requestedNodes requestd nodes on the xml stream. |
| * @return the requested nodes of the XML stream. |
| */ |
| public static List< Element > parse( InputStream xmlStream, String requestedNodes ) { |
| if( xmlStream != null && StringUtils.isNotEmpty( requestedNodes ) ) { |
| SAXBuilder builder = new SAXBuilder(); |
| try { |
| Document doc = builder.build( xmlStream ); |
| XPathFactory xpfac = XPathFactory.instance(); |
| XPathExpression< Element > xp = xpfac.compile( requestedNodes,Filters.element() ); |
| return xp.evaluate( doc ); |
| } catch ( IOException ioe ) { |
| log.error( "Couldn't load all " + xmlStream + " resources", ioe ); |
| } catch ( JDOMException jdome ) { |
| log.error( "error parsing " + xmlStream + " resources", jdome ); |
| } |
| } |
| return Collections.emptyList(); |
| } |
| |
| } |