Java tutorial
/* * * This file is part of the iText (R) project. Copyright (c) 1998-2019 iText Group NV * Authors: Bruno Lowagie, Paulo Soares, Balder Van Camp, et al. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License version 3 * as published by the Free Software Foundation with the addition of the * following permission added to Section 15 as permitted in Section 7(a): * FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY * ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT * OF THIRD PARTY RIGHTS * * 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 Affero General Public License for more details. * You should have received a copy of the GNU Affero General Public License * along with this program; if not, see http://www.gnu.org/licenses or write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA, 02110-1301 USA, or download the license from the following URL: * http://itextpdf.com/terms-of-use/ * * The interactive user interfaces in modified source and object code versions * of this program must display Appropriate Legal Notices, as required under * Section 5 of the GNU Affero General Public License. * * In accordance with Section 7(b) of the GNU Affero General Public License, * a covered work must retain the producer line in every PDF that is created * or manipulated using iText. * * You can be released from the requirements of the license by purchasing * a commercial license. Buying such a license is mandatory as soon as you * develop commercial activities involving the iText software without * disclosing the source code of your own applications. * These activities include: offering paid services to customers as an ASP, * serving PDFs on the fly in a web application, shipping iText with a closed * source product. * * For more information, please contact iText Software Corp. at this * address: sales@itextpdf.com */ package com.itextpdf.text.xml; /** * Contains utility methods for XML. * @author Balder * @since 5.0.6 * */ public class XMLUtil { /** * Escapes a string with the appropriated XML codes. * @param s the string to be escaped * @param onlyASCII codes above 127 will always be escaped with &#nn; if <CODE>true</CODE> * @return the escaped string * @since 5.0.6 */ public static String escapeXML(final String s, final boolean onlyASCII) { char cc[] = s.toCharArray(); int len = cc.length; StringBuffer sb = new StringBuffer(); for (int k = 0; k < len; ++k) { int c = cc[k]; switch (c) { case '<': sb.append("<"); break; case '>': sb.append(">"); break; case '&': sb.append("&"); break; case '"': sb.append("""); break; case '\'': sb.append("'"); break; default: if (isValidCharacterValue(c)) { if (onlyASCII && c > 127) sb.append("&#").append(c).append(';'); else sb.append((char) c); } } } return sb.toString(); } /** * Unescapes a String, replacing &#nn;, <, >, &, ", * and &apos to the corresponding characters. * @param s a String with entities * @return the unescaped string */ public static String unescapeXML(final String s) { char[] cc = s.toCharArray(); int len = cc.length; StringBuffer sb = new StringBuffer(); int pos; String esc; for (int i = 0; i < len; i++) { int c = cc[i]; if (c == '&') { pos = findInArray(';', cc, i + 3); if (pos > -1) { esc = new String(cc, i + 1, pos - i - 1); if (esc.startsWith("#")) { esc = esc.substring(1); if (isValidCharacterValue(esc)) { c = (char) Integer.parseInt(esc); i = pos; } else { i = pos; continue; } } else { int tmp = unescape(esc); if (tmp > 0) { c = tmp; i = pos; } } } } sb.append((char) c); } return sb.toString(); } /** * Unescapes 'lt', 'gt', 'apos', 'quote' and 'amp' to the * corresponding character values. * @param s a string representing a character * @return a character value */ public static int unescape(String s) { if ("apos".equals(s)) return '\''; if ("quot".equals(s)) return '"'; if ("lt".equals(s)) return '<'; if ("gt".equals(s)) return '>'; if ("amp".equals(s)) return '&'; return -1; } /** * Checks if a character value should be escaped/unescaped. * @param s the String representation of an integer * @return true if it's OK to escape or unescape this value */ public static boolean isValidCharacterValue(String s) { try { int i = Integer.parseInt(s); return isValidCharacterValue(i); } catch (NumberFormatException nfe) { return false; } } /** * Checks if a character value should be escaped/unescaped. * @param c a character value * @return true if it's OK to escape or unescape this value */ public static boolean isValidCharacterValue(int c) { return (c == 0x9 || c == 0xA || c == 0xD || c >= 0x20 && c <= 0xD7FF || c >= 0xE000 && c <= 0xFFFD || c >= 0x10000 && c <= 0x10FFFF); } /** * Looks for a character in a character array, starting from a certain position * @param needle the character you're looking for * @param haystack the character array * @param start the start position * @return the position where the character was found, or -1 if it wasn't found. */ public static int findInArray(char needle, char[] haystack, int start) { for (int i = start; i < haystack.length; i++) { if (haystack[i] == ';') return i; } return -1; } /** * Unescapes a string, replacing &lt;, &gt;, &amp;, &apos;, &quot; * and and &#nn; by the approriate characters. * @param s the string to be unescaped * @return the unescaped string * @since 5.1.3 */ /** * Returns the IANA encoding name that is auto-detected from * the bytes specified, with the endian-ness of that encoding where appropriate. * (method found in org.apache.xerces.impl.XMLEntityManager, originally published * by the Apache Software Foundation under the Apache Software License; now being * used in iText under the MPL) * @param b4 The first four bytes of the input. * @return an IANA-encoding string * @since 5.0.6 */ public static String getEncodingName(final byte[] b4) { // UTF-16, with BOM int b0 = b4[0] & 0xFF; int b1 = b4[1] & 0xFF; if (b0 == 0xFE && b1 == 0xFF) { // UTF-16, big-endian return "UTF-16BE"; } if (b0 == 0xFF && b1 == 0xFE) { // UTF-16, little-endian return "UTF-16LE"; } // UTF-8 with a BOM int b2 = b4[2] & 0xFF; if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF) { return "UTF-8"; } // other encodings int b3 = b4[3] & 0xFF; if (b0 == 0x00 && b1 == 0x00 && b2 == 0x00 && b3 == 0x3C) { // UCS-4, big endian (1234) return "ISO-10646-UCS-4"; } if (b0 == 0x3C && b1 == 0x00 && b2 == 0x00 && b3 == 0x00) { // UCS-4, little endian (4321) return "ISO-10646-UCS-4"; } if (b0 == 0x00 && b1 == 0x00 && b2 == 0x3C && b3 == 0x00) { // UCS-4, unusual octet order (2143) // REVISIT: What should this be? return "ISO-10646-UCS-4"; } if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x00) { // UCS-4, unusual octet order (3412) // REVISIT: What should this be? return "ISO-10646-UCS-4"; } if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x3F) { // UTF-16, big-endian, no BOM // (or could turn out to be UCS-2... // REVISIT: What should this be? return "UTF-16BE"; } if (b0 == 0x3C && b1 == 0x00 && b2 == 0x3F && b3 == 0x00) { // UTF-16, little-endian, no BOM // (or could turn out to be UCS-2... return "UTF-16LE"; } if (b0 == 0x4C && b1 == 0x6F && b2 == 0xA7 && b3 == 0x94) { // EBCDIC // a la xerces1, return CP037 instead of EBCDIC here return "CP037"; } // default encoding return "UTF-8"; } }