1 /* 2 * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.xml.internal.dtdparser; 27 28 29 /** 30 * This class contains static methods used to determine whether identifiers 31 * may appear in certain roles in XML documents. Such methods are used 32 * both to parse and to create such documents. 33 * 34 * @author David Brownell 35 * @version 1.1, 00/08/05 36 */ 37 public class XmlNames { 38 private XmlNames() { 39 } 40 41 42 /** 43 * Returns true if the value is a legal XML name. 44 * 45 * @param value the string being tested 46 */ 47 public static boolean isName(String value) { 48 if (value == null) 49 return false; 50 51 char c = value.charAt(0); 52 if (!XmlChars.isLetter(c) && c != '_' && c != ':') 53 return false; 54 for (int i = 1; i < value.length(); i++) 55 if (!XmlChars.isNameChar(value.charAt(i))) 56 return false; 57 return true; 58 } 59 60 /** 61 * Returns true if the value is a legal "unqualified" XML name, as 62 * defined in the XML Namespaces proposed recommendation. 63 * These are normal XML names, except that they may not contain 64 * a "colon" character. 65 * 66 * @param value the string being tested 67 */ 68 public static boolean isUnqualifiedName(String value) { 69 if (value == null || value.length() == 0) 70 return false; 71 72 char c = value.charAt(0); 73 if (!XmlChars.isLetter(c) && c != '_') 74 return false; 75 for (int i = 1; i < value.length(); i++) 76 if (!XmlChars.isNCNameChar(value.charAt(i))) 77 return false; 78 return true; 79 } 80 81 /** 82 * Returns true if the value is a legal "qualified" XML name, as defined 83 * in the XML Namespaces proposed recommendation. Qualified names are 84 * composed of an optional prefix (an unqualified name), followed by a 85 * colon, and a required "local part" (an unqualified name). Prefixes are 86 * declared, and correspond to particular URIs which scope the "local 87 * part" of the name. (This method cannot check whether the prefix of a 88 * name has been declared.) 89 * 90 * @param value the string being tested 91 */ 92 public static boolean isQualifiedName(String value) { 93 if (value == null) 94 return false; 95 96 // [6] QName ::= (Prefix ':')? LocalPart 97 // [7] Prefix ::= NCName 98 // [8] LocalPart ::= NCName 99 100 int first = value.indexOf(':'); 101 102 // no Prefix, only check LocalPart 103 if (first <= 0) 104 return isUnqualifiedName(value); 105 106 // Prefix exists, check everything 107 108 int last = value.lastIndexOf(':'); 109 if (last != first) 110 return false; 111 112 return isUnqualifiedName(value.substring(0, first)) 113 && isUnqualifiedName(value.substring(first + 1)); 114 } 115 116 /** 117 * This method returns true if the identifier is a "name token" 118 * as defined in the XML specification. Like names, these 119 * may only contain "name characters"; however, they do not need 120 * to have letters as their initial characters. Attribute values 121 * defined to be of type NMTOKEN(S) must satisfy this predicate. 122 * 123 * @param token the string being tested 124 */ 125 public static boolean isNmtoken(String token) { 126 int length = token.length(); 127 128 for (int i = 0; i < length; i++) 129 if (!XmlChars.isNameChar(token.charAt(i))) 130 return false; 131 return true; 132 } 133 134 135 /** 136 * This method returns true if the identifier is a "name token" as 137 * defined by the XML Namespaces proposed recommendation. 138 * These are like XML "name tokens" but they may not contain the 139 * "colon" character. 140 * 141 * @param token the string being tested 142 * @see #isNmtoken 143 */ 144 public static boolean isNCNmtoken(String token) { 145 return isNmtoken(token) && token.indexOf(':') < 0; 146 } 147 }