Java tutorial
// // Informa -- RSS Library for Java // Copyright (c) 2002 by Niko Schmuck // // All rights reserved. This program and the accompanying materials // are made available under the terms of the Eclipse Public License v1.0 // which accompanies this distribution, and is available at // http://www.eclipse.org/legal/epl-v10.html // package de.nava.informa.utils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jdom2.Element; import org.jdom2.Namespace; import java.net.URL; import java.text.SimpleDateFormat; import java.util.*; /** * Utility class providing convenience methods to (XML) parsing mechanisms. * * @author Niko Schmuck */ public final class ParserUtils { private static Log logger = LogFactory.getLog(ParserUtils.class); private ParserUtils() { } public static URL getURL(String toURL) { URL result = null; try { if ((toURL != null) && (toURL.trim().length() > 0)) result = new URL(toURL); } catch (java.net.MalformedURLException e) { logger.warn("Invalid URL " + toURL + " given."); } return result; } public static Namespace getDefaultNS(Element element) { return getNamespace(element, ""); } public static Namespace getNamespace(Element element, String prefix) { // Namespace ns = null; // Iterator it = element.getAdditionalNamespaces().iterator(); // while (it.hasNext()) { // Namespace curNS = (Namespace) it.next(); // if (curNS.getPrefix().equals(prefix)) { // ns = curNS; // break; // } // } return (prefix == null) ? element.getNamespace("") : element.getNamespace(prefix); } private static SimpleDateFormat[] dateFormats = null; static { final String[] possibleDateFormats = { "EEE, dd MMM yyyy HH:mm:ss z", //RFC_822 "EEE, dd MMM yyyy HH:mm zzzz", "yyyy-MM-dd'T'HH:mm:ssZ", "yyyy-MM-dd'T'HH:mm:ss.SSSzzzz", //Blogger Atom feed has millisecs also "yyyy-MM-dd'T'HH:mm:sszzzz", "yyyy-MM-dd'T'HH:mm:ss z", "yyyy-MM-dd'T'HH:mm:ssz", //ISO_8601 "yyyy-MM-dd'T'HH:mm:ss", "yyyy-MM-dd'T'HHmmss.SSSz", "yyyy-MM-dd'T'HH:mm:ss", "yyyy-MM-dd" }; dateFormats = new SimpleDateFormat[possibleDateFormats.length]; TimeZone gmtTZ = TimeZone.getTimeZone("GMT"); for (int i = 0; i < possibleDateFormats.length; i++) { dateFormats[i] = new SimpleDateFormat(possibleDateFormats[i], Locale.ENGLISH); dateFormats[i].setTimeZone(gmtTZ); } } // Mon, 07 Oct 2002 03:16:15 GMT private static SimpleDateFormat dfA = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z", Locale.ENGLISH); // 2002-09-19T02:51:16+0200 private static SimpleDateFormat dfB = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ"); // 2002-09-19T02:51:16 private static SimpleDateFormat dfC = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss"); // 2002-09-19 private static SimpleDateFormat dfD = new SimpleDateFormat("yyyy-MM-dd"); public static Date getDate(String strdate) { Date result = null; strdate = strdate.trim(); if (strdate.length() > 10) { // TODO deal with +4:00 (no zero before hour) if ((strdate.substring(strdate.length() - 5).indexOf("+") == 0 || strdate.substring(strdate.length() - 5).indexOf("-") == 0) && strdate.substring(strdate.length() - 5).indexOf(":") == 2) { String sign = strdate.substring(strdate.length() - 5, strdate.length() - 4); strdate = strdate.substring(0, strdate.length() - 5) + sign + "0" + strdate.substring(strdate.length() - 4); // logger.debug("CASE1 : new date " + strdate + " ? " // + strdate.substring(0, strdate.length() - 5)); } String dateEnd = strdate.substring(strdate.length() - 6); // try to deal with -05:00 or +02:00 at end of date // replace with -0500 or +0200 if ((dateEnd.indexOf("-") == 0 || dateEnd.indexOf("+") == 0) && dateEnd.indexOf(":") == 3) { // TODO deal with GMT-00:03 if ("GMT".equals(strdate.substring(strdate.length() - 9, strdate.length() - 6))) { logger.debug("General time zone with offset, no change "); } else { // continue treatment String oldDate = strdate; String newEnd = dateEnd.substring(0, 3) + dateEnd.substring(4); strdate = oldDate.substring(0, oldDate.length() - 6) + newEnd; // logger.debug("!!modifying string ->"+strdate); } } } int i = 0; while (i < dateFormats.length) { try { result = dateFormats[i].parse(strdate); // logger.debug("******Parsing Success "+strdate+"->"+result+" with // "+dateFormats[i].toPattern()); break; } catch (java.text.ParseException eA) { logger.debug("parsing " + strdate + " [" + dateFormats[i].toPattern() + "] without success, trying again."); i++; } } return result; } private static Date extractTimeZone(String strdate, Date thedate) { // try to extract -06:00 String tzSign = strdate.substring(strdate.length() - 6, strdate.length() - 5); String tzHour = strdate.substring(strdate.length() - 5, strdate.length() - 3); String tzMin = strdate.substring(strdate.length() - 2); if (tzSign.equals("-") || tzSign.equals("+")) { int h = Integer.parseInt(tzHour); int m = Integer.parseInt(tzMin); // NOTE: this is really plus, since perspective is from GMT if (tzSign.equals("+")) { h = -1 * h; m = -1 * m; } Calendar cal = Calendar.getInstance(); cal.setTime(thedate); cal.add(Calendar.HOUR_OF_DAY, h); cal.add(Calendar.MINUTE, m); // calculate according the used timezone cal.add(Calendar.MILLISECOND, localTimeDiff(cal.getTimeZone(), thedate)); thedate = cal.getTime(); } return thedate; } private static int localTimeDiff(TimeZone tz, Date date) { if (tz.inDaylightTime(date)) { int dstSavings = 0; if (tz.useDaylightTime()) { dstSavings = 3600000; // shortcut, JDK 1.4 allows cleaner impl } return tz.getRawOffset() + dstSavings; } return tz.getRawOffset(); } public static String formatDate(Date aDate) { return dfA.format(aDate); } public static String decodeBase64(String s) { return new String(Base64.getDecoder().decode(s)); } /** * Unescapes the string by replacing some XML entities into plain symbols. * * @param value value to unescape. * @return unescaped content. */ public static String unEscape(String value) { value = value.replaceAll("<", "<"); value = value.replaceAll(">", ">"); value = value.replaceAll("&", "&"); value = value.replaceAll(""", "\""); value = value.replaceAll("'", "'"); return value; } /** * Escapes the string by replacing reserved symbols with their XML entities. * * @param value value to escape. * @return escaped result. */ public static String escape(String value) { value = value.replaceAll("<", "<"); value = value.replaceAll(">", ">"); value = value.replaceAll("&", "&"); value = value.replaceAll("\"", """); value = value.replaceAll("'", "'"); return value; } /** * Converts names of child-tags mentioned in <code>childrenNames</code> list * to that given case. * * @param root root element. * @param childrenNames names of child tags to convert. */ public static void matchCaseOfChildren(Element root, String[] childrenNames) { if (root == null || childrenNames.length == 0) return; // Prepare list of names int namesCount = childrenNames.length; Map<String, String> names = new HashMap<>(namesCount); for (String childName : childrenNames) { if (childName != null) { String lower = childName.toLowerCase(); if (!names.containsKey(lower)) names.put(lower, childName); } } // Walk through the children elements List elements = root.getChildren(); for (Object element : elements) { Element child = (Element) element; String childName = child.getName().toLowerCase(); if (names.containsKey(childName)) child.setName(names.get(childName)); } } /** * Converts names of child-tags mentioned in <code>childName</code> list * to that given case. * * @param root root element. * @param childName name of child tags to convert. */ public static void matchCaseOfChildren(Element root, String childName) { if (root == null || childName == null) return; // Walk through the children elements List elements = root.getChildren(); for (Object element : elements) { Element child = (Element) element; String name = child.getName().toLowerCase(); if (name.equalsIgnoreCase(childName)) child.setName(childName); } } }