View Javadoc
1   /*
2    * Redistribution and use of this software and associated documentation
3    * ("Software"), with or without modification, are permitted provided
4    * that the following conditions are met:
5    *
6    * 1. Redistributions of source code must retain copyright
7    *    statements and notices.  Redistributions must also contain a
8    *    copy of this document.
9    *
10   * 2. Redistributions in binary form must reproduce the
11   *    above copyright notice, this list of conditions and the
12   *    following disclaimer in the documentation and/or other
13   *    materials provided with the distribution.
14   *
15   * 3. The name "Exolab" must not be used to endorse or promote
16   *    products derived from this Software without prior written
17   *    permission of Intalio, Inc.  For written permission,
18   *    please contact info@exolab.org.
19   *
20   * 4. Products derived from this Software may not be called "Exolab"
21   *    nor may "Exolab" appear in their names without prior written
22   *    permission of Intalio, Inc. Exolab is a registered
23   *    trademark of Intalio, Inc.
24   *
25   * 5. Due credit should be given to the Exolab Project
26   *    (http://www.exolab.org/).
27   *
28   * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
29   * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30   * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31   * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
32   * INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33   * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39   * OF THE POSSIBILITY OF SUCH DAMAGE.
40   *
41   * Copyright 1999-2002 (C) Intalio, Inc. All Rights Reserved.
42   *
43   * $Id$
44   */
45  package org.exolab.castor.xml.validators;
46  
47  /**
48   * A static class for performing simple validation.
49   *
50   * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
51   * @version $Revision$ $Date: 2003-03-03 00:05:44 -0700 (Mon, 03 Mar 2003) $
52   */
53  public final class ValidationUtils {
54  
55      // ----------------/
56      // - Constructors -/
57      // ----------------/
58  
59      /**
60       * No-arg constructor.
61       */
62      private ValidationUtils() {
63          super();
64      }
65  
66      // ------------------/
67      // - Public Methods -/
68      // ------------------/
69  
70      /**
71       * Checks the given character to determine if it is a valid CombiningChar as
72       * defined by the W3C XML 1.0 Recommendation.
73       * <p>
74       * FIXME: This method needs to be properly implemented.
75       * @param ch THe character to check.
76       *
77       * @return true if the given character is a CombiningChar
78       */
79      public static boolean isCombiningChar(final char ch) {
80          // -- NOTE: THIS METHOD IS NOT COMPLETE
81          return false;
82      } // -- isCombiningChar
83  
84      /**
85       * Checks a character to see if it is a digit or not.
86       * @param ch
87       *            the character to check
88       * @return true if the given character is a digit
89       */
90      public static boolean isDigit(final char ch) {
91          return Character.isDigit(ch);
92      } // -- isDigit
93  
94      /**
95       * Checks a character to see if it is a letter or not.
96       * @param ch
97       *            the character to check
98       * @return true if the given character is a letter
99       */
100     public static boolean isLetter(final char ch) {
101         return Character.isLetter(ch);
102     } // -- isLetter
103 
104     /**
105      * Checks all characters of the given String to determine if they
106      * syntactically match the production of an NCName as defined by the W3C XML
107      * Namespaces recommendation.
108      *
109      * @param str
110      *            the String to check
111      * @return true if the given String follows the Syntax of an NCName
112      */
113     public static boolean isNCName(final String str) {
114         if (str == null || str.length() == 0) {
115             return false;
116         }
117 
118         char[] chars = str.toCharArray();
119 
120         // -- make sure String starts with a letter or '_'
121         char ch = chars[0];
122         if (!isLetter(ch) && ch != '_') {
123             return false;
124         }
125 
126         for (int i = 1; i < chars.length; i++) {
127             if (!isNCNameChar(chars[i])) {
128                 return false;
129             }
130         }
131         return true;
132     } // -- isNCName
133 
134     /**
135      * Checks the the given character to determine if it is a valid NCNameChar
136      * as defined by the W3C XML Namespaces recommendation.
137      *
138      * @param ch
139      *            the char to check
140      * @return true if the given char is an NCNameChar
141      */
142     public static boolean isNCNameChar(final char ch) {
143         if (isLetter(ch) || isDigit(ch)) {
144             return true;
145         }
146 
147         if (isExtender(ch) || isCombiningChar(ch)) {
148             return true;
149         }
150 
151         switch (ch) {
152             case '.':
153             case '-':
154             case '_':
155                 return true;
156             default:
157                 return false;
158         }
159     } // -- isNCNameChar
160 
161     /**
162      * Checks all characters of the given String to determine if they
163      * syntactically match the production of an NMToken.
164      *
165      * @param str
166      *            the String to check
167      * @return true if the given String follows the Syntax of an NMToken
168      */
169     public static boolean isNMToken(final String str) {
170         if (str == null) {
171             return false;
172         }
173 
174         char[] chars = str.toCharArray();
175 
176         for (int i = 0; i < chars.length; i++) {
177             char ch = chars[i];
178             if (isLetter(ch) || isDigit(ch) || isExtender(ch) || isCombiningChar(ch)) {
179                 continue;
180             }
181 
182             switch (ch) {
183                 case '.':
184                 case '-':
185                 case '_':
186                 case ':':
187                     break;
188                 default:
189                     return false;
190             }
191         }
192         return true;
193     } // -- isNMToken
194 
195     /**
196      * Checks all characters of the given String to determine if they
197      * syntactically match the production of a CDATA.
198      *
199      * @param str
200      *            the String to check
201      * @return true if the given String follows the Syntax of an NMToken
202      */
203     public static boolean isCDATA(final String str) {
204         if (str == null) {
205             return false;
206         }
207 
208         char[] chars = str.toCharArray();
209 
210         for (int i = 0; i < chars.length; i++) {
211             char ch = chars[i];
212             switch (ch) {
213                 case '\r':
214                 case '\n':
215                 case '\t':
216                     return false;
217                 default:
218                     continue;
219             }
220         }
221         return true;
222     } // -- isCDATA
223 
224     /**
225      * Returns true if the given character is a valid XML Extender character,
226      * according to the XML 1.0 specification.
227      *
228      * @param ch
229      *            the character to check
230      * @return true if the character is a valid XML Extender character
231      */
232     public static boolean isExtender(final char ch) {
233         if ((ch >= 0x3031) && (ch <= 0x3035)) {
234             return true;
235         }
236 
237         if ((ch >= 0x30FC) && (ch <= 0x30FE)) {
238             return true;
239         }
240 
241         switch (ch) {
242             case 0x00B7:
243             case 0x02D0:
244             case 0x02D1:
245             case 0x0387:
246             case 0x0640:
247             case 0x0E46:
248             case 0x0EC6:
249             case 0x3005:
250             case 0x309D:
251             case 0x309E:
252                 return true;
253             default:
254                 break;
255         }
256         return false;
257     } // -- isExtender
258 
259     /**
260      * Checks all characters of the given String to determine if they
261      * syntactically match the production of an QName as defined by the W3C XML
262      * Namespaces recommendation.
263      *
264      * @param str
265      *            the String to check
266      * @return true if the given String follows the Syntax of an QName
267      */
268     public static boolean isQName(final String str) {
269         if (str == null || str.length() == 0) {
270             return false;
271         }
272 
273         char[] chars = str.toCharArray();
274 
275         // -- make sure String starts with a letter or '_'
276         char ch = chars[0];
277         if (!isLetter(ch) && ch != '_') {
278             return false;
279         }
280 
281         for (int i = 1; i < chars.length; i++) {
282             if (chars[i] == ':') {
283                 continue;
284             }
285 
286             if (!isNCNameChar(chars[i])) {
287                 return false;
288             }
289         }
290         return true;
291     } //-- isQName
292 
293 } //-- Validator