Java tutorial
/* * Sonar W3C Markup Validation Plugin * Copyright (C) 2010 Matthijs Galesloot * dev@sonar.codehaus.org * * Licensed 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.sonar.plugins.web.markup.rules; import java.io.FileWriter; import java.io.IOException; import java.io.Serializable; import java.util.ArrayList; import java.util.Collections; import java.util.Comparator; import java.util.HashMap; import java.util.List; import java.util.Map; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.StringEscapeUtils; import org.apache.commons.lang.StringUtils; import org.apache.commons.lang.math.NumberUtils; import org.apache.log4j.Logger; import org.apache.xerces.parsers.DOMParser; import org.sonar.api.utils.SonarException; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.NodeList; import org.xml.sax.InputSource; import org.xml.sax.SAXException; /** * Parse w3c page with the full list of HTML errors. * * @see http://validator.w3.org/docs/errors.html - Explanation of the error messages for the W3C Markup Validator * * @author Matthijs Galesloot * @since 1.0 */ public class MarkupErrorCatalog { private static final class MessageDefinitionComparator implements Comparator<MessageDefinition>, Serializable { private static final long serialVersionUID = 1L; public int compare(MessageDefinition e1, MessageDefinition e2) { return e1.id.compareTo(e2.id); } } public static class MessageDefinition { private String explanation; private String id; private String remark; public String getExplanation() { return explanation; } public String getId() { return id; } public String getRemark() { return remark; } } private static final Logger LOG = Logger.getLogger(MarkupErrorCatalog.class); public static void main(String[] args) { new MarkupErrorCatalog().createRulesCatalog(); } private final List<MessageDefinition> errors; private final List<MessageDefinition> warnings; public MarkupErrorCatalog() { errors = new ArrayList<MessageDefinition>(); readErrorCatalog(); warnings = new ArrayList<MessageDefinition>(); readWarningCatalog(); } /** * method to generate rules.xml for use in WebscannerPlugin. */ private void createRulesCatalog() { FileWriter writer = null; try { writer = new FileWriter("markup-errors.xml"); writer.write("<rules>"); for (MessageDefinition error : errors) { String remark = StringEscapeUtils.escapeXml(StringUtils.substringAfter(error.remark, ":")); String id = makeIdentifier(error.id); String explanation = StringEscapeUtils.escapeXml(error.explanation); writer.write(String.format( "<rule><key>%s</key><remark>%s:%s</remark><priority>MAJOR</priority>" + "<explanation>%s</explanation></rule>\n", id, id, remark, explanation == null ? "" : explanation)); } for (MessageDefinition warning : warnings) { String remark = StringEscapeUtils.escapeXml(warning.remark); String id = makeIdentifier(warning.id); String explanation = StringEscapeUtils.escapeXml(warning.explanation); writer.write(String.format( "<rule><key>%s</key><remark>%s:%s</remark><priority>MINOR</priority>" + "<explanation>%s</explanation></rule>\n", id, id, remark, explanation == null ? "" : explanation)); } writer.write("</rules>"); writer.close(); } catch (IOException e) { throw new SonarException(e); } finally { IOUtils.closeQuietly(writer); } } private String makeIdentifier(String idString) { int id = NumberUtils.toInt(idString, -1); if (id >= 0) { return String.format("%03d", id); } else { return idString; } } private Element findDiv(Element element) { for (int i = 0; i < element.getChildNodes().getLength(); i++) { if ("div".equals(element.getChildNodes().item(i).getNodeName())) { return (Element) element.getChildNodes().item(i); } } return null; } public MessageDefinition findErrorDefinition(String messageId) { for (MessageDefinition error : errors) { if (error.id.equals(messageId)) { return error; } } return null; } private Map<String, String> findExplanations(Document document) { NodeList explanationNodeList = document.getElementsByTagName("dd"); Map<String, String> explanations = new HashMap<String, String>(); for (int i = 0; i < explanationNodeList.getLength(); i++) { Element element = (Element) explanationNodeList.item(i); Element div = findDiv(element); String clazz = div.getAttribute("class"); String id = StringUtils.substringAfterLast(clazz, "-"); explanations.put(id, div.getTextContent()); } return explanations; } private String getGrandChildContent(Element element, String nodeName) { for (int i = 0; i < element.getChildNodes().getLength(); i++) { if (nodeName.equals(element.getChildNodes().item(i).getNodeName())) { return element.getChildNodes().item(i).getChildNodes().item(0).getNodeValue(); } } return "?"; } private String getChildContent(Element element, String nodeName) { for (int i = 0; i < element.getChildNodes().getLength(); i++) { if (nodeName.equals(element.getChildNodes().item(i).getNodeName())) { return element.getChildNodes().item(i).getTextContent(); } } return "?"; } private Document parseMessageCatalog(String fileName) { DOMParser parser = new DOMParser(); try { parser.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false); parser.parse(new InputSource(MarkupErrorCatalog.class.getClassLoader() .getResourceAsStream("org/sonar/plugins/web/markup/errors/" + fileName))); } catch (SAXException se) { throw new SonarException(se); } catch (IOException ioe) { throw new SonarException(ioe); } return parser.getDocument(); } private void readErrorCatalog() { Document document = parseMessageCatalog("markup-errors.html"); NodeList nodeList = document.getElementsByTagName("dt"); // find errors with explanation for (int i = 0; i < nodeList.getLength(); i++) { Element element = (Element) nodeList.item(i); if (element.hasAttribute("id")) { MessageDefinition error = new MessageDefinition(); String id = element.getAttribute("id"); error.id = StringUtils.substringAfterLast(id, "-"); error.remark = element.getChildNodes().item(0).getNodeValue().trim(); errors.add(error); } } // find explanation for the first group of errors Map<String, String> explanations = findExplanations(document); for (MessageDefinition error : errors) { error.explanation = explanations.get(error.id); if (error.explanation == null) { LOG.error("Could not find explanation for " + error.id); } } // find errors without explanation nodeList = document.getElementsByTagName("li"); for (int i = 0; i < nodeList.getLength(); i++) { Element element = (Element) nodeList.item(i); if (element.hasAttribute("id")) { MessageDefinition error = new MessageDefinition(); String id = element.getAttribute("id"); error.id = StringUtils.substringAfterLast(id, "-"); error.remark = getGrandChildContent(element, "p").trim(); errors.add(error); } } } private void readWarningCatalog() { Document document = parseMessageCatalog("markup-warnings.xml"); NodeList nodeList = document.getElementsByTagName("rule"); // find warnings with explanation for (int i = 0; i < nodeList.getLength(); i++) { Element element = (Element) nodeList.item(i); MessageDefinition message = new MessageDefinition(); message.id = getChildContent(element, "key"); message.remark = getChildContent(element, "remark"); warnings.add(message); } // sort the errors on id Collections.sort(warnings, new MessageDefinitionComparator()); } }