Java tutorial
/* * RHQ Management Platform * Copyright (C) 2005-2008 Red Hat, Inc. * All rights reserved. * * This program 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 version 2 of the License. * * 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ package org.rhq.helpers.bundleGen; import java.io.BufferedReader; import java.io.FileNotFoundException; import java.io.InputStream; import java.util.Collections; import java.util.HashMap; import java.util.Locale; import java.lang.reflect.Method; import java.util.Map; import java.util.ResourceBundle; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; /** * Reads questions from an XML file and shows them to the user. * The reader first tries to load a locale based version of the * questions (file.<locale>.xml) if this fails, it falls back * to using a default version (file.xml) * * @author Heiko W. Rupp */ public class XmlQuestionsReader { private final Log log = LogFactory.getLog(XmlQuestionsReader.class); String baseName; ResourceBundle resourceBundle = ResourceBundle.getBundle("bundleGen"); /** * Create a new XmlQuestionReader * @param fileBaseName the basename of a file - sans .xml suffix! */ public XmlQuestionsReader(String fileBaseName) { baseName = fileBaseName; } /** * Present the questions to the user and read answers from the provided <i>reader</i>. * @param reader Buffered Reader to read from. Usually an InputStreamReader(System.in) * @param props Props object to fill the answers into. * @throws FileNotFoundException if no question file is found * @throws Exception On various other occasions */ public void readQuestions(BufferedReader reader, Props props) throws Exception { try { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = factory.newDocumentBuilder(); Class<? extends XmlQuestionsReader> clazz = getClass(); String lang = Locale.getDefault().getLanguage(); InputStream input = clazz.getResourceAsStream("/" + baseName + ".xml"); if (input == null) { throw new FileNotFoundException("Input file [" + baseName + "] not found"); } Document doc = builder.parse(input); Element root = doc.getDocumentElement(); // <questions> NodeList questionNodes = root.getChildNodes();// "question|block" for (int i = 0; i < questionNodes.getLength(); i++) { Node node = questionNodes.item(i); if (node instanceof Element) { String nodeName = node.getNodeName(); if (nodeName.equals("question")) { Element question = (Element) node; String res = handleQuestion(reader, question, lang); String prop = question.getAttribute("prop"); String type = question.getAttribute("type"); fillObject(props, prop, type, res); } else if (nodeName.equals("block")) { // Map res = handleBlock(reader,node,props,lang); // TODO } } } } catch (Exception e) { e.printStackTrace(); } } private void handleBlock(BufferedReader reader, Node node, Props props, String lang) throws Exception { Element block = (Element) node; String repeat = block.getAttribute("repeat"); if (repeat == null || repeat.isEmpty()) repeat = "one"; int repeatCount = 0; // for () { // // first ask the standalone question and decide from there // Element question = (Element) block.getElementsByTagName("question").item(0); // // // // Now loop over the questions // NodeList questions = block.getElementsByTagName("question"); // for (int i = 1; i < questions.getLength(); i++) { // Node qnode = questions.item(i); // // handleQuestion(reader,qnode,props,lang); TODO // } // } } /** * Handle <question> elements * @param reader * @param question * @param lang * @throws Exception */ private String handleQuestion(BufferedReader reader, Element question, String lang) throws Exception { String type = question.getAttribute("type"); if (type.equals("")) type = "string"; if (!isValidType(type)) { System.err.println("Type " + type + " is invalid in " + question); return null; } Element text = getElementForLang(question, "text", lang); NodeList prefillNodes = question.getElementsByTagName("prefill"); String prefill = null; if (prefillNodes.getLength() > 0) { prefill = prefillNodes.item(0).getTextContent(); } Element helpNode = getElementForLang(question, "help", lang); String help = null; if (helpNode != null) { help = helpNode.getTextContent(); } System.out.print(text.getTextContent()); if ("bool".equals(type)) { System.out.print(resourceBundle.getString("yes.no")); } if (prefill != null) { System.out.print("[" + prefill + "]"); } String answer; boolean helpRequested = false; do { helpRequested = false; System.out.print(": "); answer = reader.readLine(); if (answer.startsWith("?")) { helpRequested = true; if (help != null) { System.out.println(help); } else System.out.println(resourceBundle.getString("no.help.available")); } } while (helpRequested); if (type.equals("bool")) { String yesString = resourceBundle.getString("yes.key"); if (answer.toLowerCase(Locale.getDefault()).startsWith(yesString)) return Boolean.TRUE.toString(); else return Boolean.FALSE.toString(); } else { if (prefill != null && answer.length() == 0) { return prefill; } else return answer; } } /** * Search for an element <i>tagWanted</i> within parent. If multiple * elements are present, use the one with the matching <i>lang</i>. * If no matching element is present, use one without a <i>lang</i> * attribute * @param parent containing element * @param tagWanted the tag to search for * @param lang the desired language version * @return an element or null if not found */ Element getElementForLang(Element parent, String tagWanted, String lang) { NodeList elements = parent.getElementsByTagName(tagWanted); if (elements == null || elements.getLength() == 0) return null; Element noLang = (Element) elements.item(0); for (int i = 0; i < elements.getLength(); i++) { Element ele = (Element) elements.item(i); String attr = ele.getAttribute("lang"); if (attr == null || attr.isEmpty()) { noLang = ele; } else if (attr.equals(lang)) { return ele; } } return noLang; } private void fillObject(Object target, String prop, String type, String res) throws Exception { String setterName = "set" + caps(prop); Method setter; Class clazz = target.getClass(); Method[] methods = clazz.getDeclaredMethods(); if ("bool".equals(type)) { setter = clazz.getMethod(setterName, Boolean.TYPE); setter.invoke(target, Boolean.valueOf(res)); } else { setter = clazz.getMethod(setterName, String.class); setter.invoke(target, res); } } /** * Returns true if the passed type is a valid data type of the properties (not for a single * property). * @param type A type as string * @return true if its valid, false otherwise */ private boolean isValidType(String type) { if ("bool".equals(type) || "string".equals(type)) return true; return false; } static String caps(String in) { if (in == null) return null; return in.substring(0, 1).toUpperCase(Locale.getDefault()) + in.substring(1); } }