Java tutorial
//package com.java2s; /* * Copyright (c) 2004, simontsui, Chris Leung. 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. */ public class Main { /** * @return true if substring started at 'start' is a XML entity reference. */ public static boolean isXmlEntityRef(CharSequence str, int start) { int len = str.length(); if (start >= len || str.charAt(start) != '&') return false; if (++start >= len) return false; if (str.charAt(start) == '#') return isXmlCharRefPart(str, start + 1); int i = start; if (!isNameStart(str.charAt(i))) return false; for (++i; i < len; ++i) { if (!isName(str.charAt(i))) break; } return (i > start && i < len && str.charAt(i) == ';'); } /** * NOTE: No well-formness check for the referenced char. * * @param start Index to char after "&#". */ public static boolean isXmlCharRefPart(CharSequence str, int start) { int len = str.length(); if (start >= len) return false; char c; if (str.charAt(start) == 'x') { // &#xhex; ++start; int i = start; for (; i < len; ++i) { c = str.charAt(i); if ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')) continue; break; } return (i > start && i < len && str.charAt(i) == ';'); } // &#dec; int i = start; for (; i < len; ++i) { c = str.charAt(i); if (c < '0' || c > '9') break; } return (i > start && i < len && str.charAt(i) == ';'); } public static boolean isNameStart(int c) { return c == ':' || c >= 'A' && c <= 'Z' || c == '_' || c >= 'a' && c <= 'z' || c >= '\u00C0' && c <= '\u00D6' || c >= '\u00D8' && c <= '\u00F6' || c >= '\u00F8' && c <= '\u02FF' || c >= '\u0370' && c <= '\u037D' || c >= '\u037F' && c <= '\u1FFF' || c >= '\u200C' && c <= '\u200D' || c >= '\u2070' && c <= '\u218F' || c >= '\u2C00' && c <= '\u2FEF' || c >= '\u3001' && c <= '\uD7FF' || c >= '\uF900' && c <= '\uFDCF' || c >= '\uFDF0' && c <= '\uFFFD' // | '\x00010000'..'\x000EFFFF' ; } public static boolean isName(int c) { return isNameStart(c) || c == '-' || c == '.' || c >= '0' && c <= '9' || c == '\u00B7' || c >= '\u0300' && c <= '\u036F' || c >= '\u203F' && c <= '\u2040'; } }