Source code

001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License.
018 *
019 */
020package org.apache.directory.api.util;
021
022
023/**
024 * Various Character methods are kept here.
025 *
026 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
027 */
028public final class Chars
029{
030    /** &lt;alpha&gt; ::= [0x41-0x5A] | [0x61-0x7A] */
031    private static final boolean[] ALPHA =
032        {
033            false, false, false, false, false, false, false, false,
034            false, false, false, false, false, false, false, false,
035            false, false, false, false, false, false, false, false,
036            false, false, false, false, false, false, false, false,
037            false, false, false, false, false, false, false, false,
038            false, false, false, false, false, false, false, false,
039            false, false, false, false, false, false, false, false,
040            false, false, false, false, false, false, false, false,
041            false,  true,  true,  true,  true,  true,  true,  true,
042            true,   true,  true,  true,  true,  true,  true,  true,
043            true,   true,  true,  true,  true,  true,  true,  true,
044            true,   true,  true, false, false, false, false, false,
045            false,  true,  true,  true,  true,  true,  true,  true,
046            true,   true,  true,  true,  true,  true,  true,  true,
047            true,   true,  true,  true,  true,  true,  true,  true,
048            true,   true,  true, false, false, false, false, false
049        };
050    
051    /** &lt;alpha-lower-case&gt; ::= [0x61-0x7A] */
052    private static final boolean[] ALPHA_LOWER_CASE =
053        {
054            false, false, false, false, false, false, false, false,
055            false, false, false, false, false, false, false, false,
056            false, false, false, false, false, false, false, false,
057            false, false, false, false, false, false, false, false,
058            false, false, false, false, false, false, false, false,
059            false, false, false, false, false, false, false, false,
060            false, false, false, false, false, false, false, false,
061            false, false, false, false, false, false, false, false,
062            false, false, false, false, false, false, false, false,
063            false, false, false, false, false, false, false, false,
064            false, false, false, false, false, false, false, false,
065            false, false, false, false, false, false, false, false,
066            false,  true,  true,  true,  true,  true,  true,  true,
067            true,   true,  true,  true,  true,  true,  true,  true,
068            true,   true,  true,  true,  true,  true,  true,  true,
069            true,   true,  true, false, false, false, false, false
070        };
071    
072    /** &lt;alpha-upper-case&gt; ::= [0x41-0x5A] */
073    private static final boolean[] ALPHA_UPPER_CASE =
074        {
075            false, false, false, false, false, false, false, false,
076            false, false, false, false, false, false, false, false,
077            false, false, false, false, false, false, false, false,
078            false, false, false, false, false, false, false, false,
079            false, false, false, false, false, false, false, false,
080            false, false, false, false, false, false, false, false,
081            false, false, false, false, false, false, false, false,
082            false, false, false, false, false, false, false, false,
083            false,  true,  true,  true,  true,  true,  true,  true,
084            true,   true,  true,  true,  true,  true,  true,  true,
085            true,   true,  true,  true,  true,  true,  true,  true,
086            true,   true,  true, false, false, false, false, false,
087            false, false, false, false, false, false, false, false,
088            false, false, false, false, false, false, false, false,
089            false, false, false, false, false, false, false, false,
090            false, false, false, false, false, false, false, false,
091        };
092    
093    /** &lt;alpha-digit&gt; | &lt;digit&gt; */
094    private static final boolean[] ALPHA_DIGIT =
095        {
096            false, false, false, false, false, false, false, false,
097            false, false, false, false, false, false, false, false,
098            false, false, false, false, false, false, false, false,
099            false, false, false, false, false, false, false, false,
100            false, false, false, false, false, false, false, false,
101            false, false, false, false, false, false, false, false,
102            true,   true,  true,  true,  true,  true,  true,  true,
103            true,   true, false, false, false, false, false, false,
104            false,  true,  true,  true,  true,  true,  true,  true,
105            true,   true,  true,  true,  true,  true,  true,  true,
106            true,   true,  true,  true,  true,  true,  true,  true,
107            true,   true,  true, false, false, false, false, false,
108            false,  true,  true,  true,  true,  true,  true,  true,
109            true,   true,  true,  true,  true,  true,  true,  true,
110            true,   true,  true,  true,  true,  true,  true,  true,
111            true,   true,  true, false, false, false, false, false
112        };
113    
114    /** &lt;alpha&gt; | &lt;digit&gt; | '-' */
115    private static final boolean[] CHAR =
116        {
117            false, false, false, false, false, false, false, false,
118            false, false, false, false, false, false, false, false,
119            false, false, false, false, false, false, false, false,
120            false, false, false, false, false, false, false, false,
121            false, false, false, false, false, false, false, false,
122            false, false, false, false, false, true,  false, false,
123            true,   true,  true,  true,  true,  true,  true,  true,
124            true,   true, false, false, false, false, false, false,
125            false,  true,  true,  true,  true,  true,  true,  true,
126            true,   true,  true,  true,  true,  true,  true,  true,
127            true,   true,  true,  true,  true,  true,  true,  true,
128            true,   true,  true, false, false, false, false, false,
129            false,  true,  true,  true,  true,  true,  true,  true,
130            true,   true,  true,  true,  true,  true,  true,  true,
131            true,   true,  true,  true,  true,  true,  true,  true,
132            true,   true,  true, false, false, false, false, false
133        };
134    
135    /** '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' */
136    private static final boolean[] DIGIT =
137        {
138            false, false, false, false, false, false, false, false,
139            false, false, false, false, false, false, false, false,
140            false, false, false, false, false, false, false, false,
141            false, false, false, false, false, false, false, false,
142            false, false, false, false, false, false, false, false,
143            false, false, false, false, false, false, false, false,
144            true,   true,  true,  true,  true,  true,  true,  true,
145            true,   true, false, false, false, false, false, false,
146            false, false, false, false, false, false, false, false,
147            false, false, false, false, false, false, false, false,
148            false, false, false, false, false, false, false, false,
149            false, false, false, false, false, false, false, false,
150            false, false, false, false, false, false, false, false,
151            false, false, false, false, false, false, false, false,
152            false, false, false, false, false, false, false, false,
153            false, false, false, false, false, false, false, false
154        };
155    
156    /** &lt;hex&gt; ::= [0x30-0x39] | [0x41-0x46] | [0x61-0x66] */
157    private static final boolean[] HEX =
158        {
159            false, false, false, false, false, false, false, false,
160            false, false, false, false, false, false, false, false,
161            false, false, false, false, false, false, false, false,
162            false, false, false, false, false, false, false, false,
163            false, false, false, false, false, false, false, false,
164            false, false, false, false, false, false, false, false,
165            true,   true,  true,  true,  true,  true,  true,  true,
166            true,   true, false, false, false, false, false, false,
167            false,  true,  true,  true,  true,  true,  true, false,
168            false, false, false, false, false, false, false, false,
169            false, false, false, false, false, false, false, false,
170            false, false, false, false, false, false, false, false,
171            false,  true,  true,  true,  true,  true,  true, false,
172            false, false, false, false, false, false, false, false,
173            false, false, false, false, false, false, false, false,
174            false, false, false, false, false, false, false, false 
175        };
176
177
178    private Chars()
179    {
180    }
181
182
183    /**
184    * Test if the current character is equal to a specific character.
185    *
186    * @param chars The buffer which contains the data
187    * @param index
188    *            Current position in the buffer
189    * @param car The character we want to compare with the current buffer position
190    * @return <code>true</code> if the current character equals the given character.
191    */
192    public static boolean isCharASCII( char[] chars, int index, char car )
193    {
194        if ( ( chars == null ) || ( chars.length == 0 ) || ( index < 0 ) || ( index >= chars.length ) )
195        {
196            return false;
197        }
198        else
199        {
200            return chars[index] == car;
201        }
202    }
203
204
205    /**
206     * Test if the current character is equal to a specific character.
207     *
208     * @param string The String which contains the data
209     * @param index Current position in the string
210     * @param car The character we want to compare with the current string
211     *            position
212     * @return <code>true</code> if the current character equals the given
213     *         character.
214     */
215    public static boolean isCharASCII( String string, int index, char car )
216    {
217        if ( string == null )
218        {
219            return false;
220        }
221
222        int length = string.length();
223
224        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
225        {
226            return false;
227        }
228        else
229        {
230            return string.charAt( index ) == car;
231        }
232    }
233
234
235    /**
236     * Test if the current character is equal to a specific character.
237     *
238     * @param string The String which contains the data
239     * @param index Current position in the string
240     * @param car The character we want to compare with the current string
241     *            position
242     * @return <code>true</code> if the current character equals the given
243     *         character.
244     */
245    public static boolean isICharASCII( String string, int index, char car )
246    {
247        if ( string == null )
248        {
249            return false;
250        }
251
252        int length = string.length();
253
254        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
255        {
256            return false;
257        }
258        else
259        {
260            return ( ( string.charAt( index ) | 0x20 ) & car ) == car;
261        }
262    }
263
264
265    /**
266     * Test if the current character is equal to a specific character.
267     *
268     * @param bytes The String which contains the data
269     * @param index Current position in the string
270     * @param car The character we want to compare with the current string
271     *            position
272     * @return <code>true</code> if the current character equals the given
273     *         character.
274     */
275    public static boolean isICharASCII( byte[] bytes, int index, char car )
276    {
277        if ( bytes == null )
278        {
279            return false;
280        }
281
282        int length = bytes.length;
283
284        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
285        {
286            return false;
287        }
288        else
289        {
290            return ( ( bytes[index] | 0x20 ) & car ) == car;
291        }
292    }
293
294
295    /**
296     * Test if the current byte is an Alpha character :
297     * &lt;alpha&gt; ::= [0x41-0x5A] | [0x61-0x7A]
298     *
299     * @param c The byte to test
300     *
301     * @return <code>true</code> if the byte is an Alpha
302     *         character
303     */
304    public static boolean isAlpha( byte c )
305    {
306        return ( c > 0 ) && ( c <= 127 ) && ALPHA[c];
307    }
308
309
310    /**
311     * Test if the current character is an Alpha character :
312     * &lt;alpha&gt; ::= [0x41-0x5A] | [0x61-0x7A]
313     *
314     * @param c The char to test
315     *
316     * @return <code>true</code> if the character is an Alpha
317     *         character
318     */
319    public static boolean isAlpha( char c )
320    {
321        return ( c > 0 ) && ( c <= 127 ) && ALPHA[c];
322    }
323
324
325    /**
326     * Test if the current character is an Alpha character : &lt;alpha&gt; ::=
327     * [0x41-0x5A] | [0x61-0x7A]
328     *
329     * @param bytes The buffer which contains the data
330     * @param index Current position in the buffer
331     * @return <code>true</code> if the current character is an Alpha
332     *         character
333     */
334    public static boolean isAlphaASCII( byte[] bytes, int index )
335    {
336        if ( ( bytes == null ) || ( bytes.length == 0 ) || ( index < 0 ) || ( index >= bytes.length ) )
337        {
338            return false;
339        }
340        else
341        {
342            byte c = bytes[index];
343
344            return ( ( c | 0x7F ) == 0x7F ) && ALPHA[c];
345        }
346    }
347
348
349    /**
350     * Test if the current character is an Alpha character : &lt;alpha&gt; ::=
351     * [0x41-0x5A] | [0x61-0x7A]
352     *
353     * @param chars The buffer which contains the data
354     * @param index Current position in the buffer
355     * @return <code>true</code> if the current character is an Alpha
356     *         character
357     */
358    public static boolean isAlphaASCII( char[] chars, int index )
359    {
360        if ( ( chars == null ) || ( chars.length == 0 ) || ( index < 0 ) || ( index >= chars.length ) )
361        {
362            return false;
363        }
364        else
365        {
366            char c = chars[index];
367
368            return ( ( c | 0x007F ) == 0x007F ) && ALPHA[c];
369        }
370    }
371
372
373    /**
374     * Test if the current character is an Alpha character : &lt;alpha&gt; ::=
375     * [0x41-0x5A] | [0x61-0x7A]
376     *
377     * @param string The string which contains the data
378     * @param index Current position in the string
379     * @return <code>true</code> if the current character is an Alpha
380     *         character
381     */
382    public static boolean isAlphaASCII( String string, int index )
383    {
384        if ( string == null )
385        {
386            return false;
387        }
388
389        int length = string.length();
390
391        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
392        {
393            return false;
394        }
395        else
396        {
397            char c = string.charAt( index );
398
399            return ( ( c | 0x007F ) == 0x007F ) && ALPHA[c];
400        }
401    }
402
403
404    /**
405     * Test if the current character is a lowercased Alpha character : <br>
406     * &lt;alpha&gt; ::= [0x61-0x7A]
407     *
408     * @param string The string which contains the data
409     * @param index Current position in the string
410     * @return <code>true</code> if the current character is a lower Alpha
411     *         character
412     */
413    public static boolean isAlphaLowercaseASCII( String string, int index )
414    {
415        if ( string == null )
416        {
417            return false;
418        }
419
420        int length = string.length();
421
422        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
423        {
424            return false;
425        }
426        else
427        {
428            char c = string.charAt( index );
429
430            return ( ( c | 0x007F ) == 0x007F ) && ALPHA_LOWER_CASE[c];
431        }
432    }
433
434
435    /**
436     * Test if the current character is a uppercased Alpha character : <br>
437     * &lt;alpha&gt; ::= [0x61-0x7A]
438     *
439     * @param string The string which contains the data
440     * @param index Current position in the string
441     * @return <code>true</code> if the current character is a lower Alpha
442     *         character
443     */
444    public static boolean isAlphaUppercaseASCII( String string, int index )
445    {
446        if ( string == null )
447        {
448            return false;
449        }
450
451        int length = string.length();
452
453        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
454        {
455            return false;
456        }
457        else
458        {
459            char c = string.charAt( index );
460
461            return ( c <= 127 ) && ALPHA_UPPER_CASE[c];
462        }
463    }
464
465
466    /**
467     * Check if the current character is an 7 bits ASCII CHAR (between 0 and
468     * 127).
469     * &lt;char&gt; ::= &lt;alpha&gt; | &lt;digit&gt;
470     *
471     * @param string The string which contains the data
472     * @param index Current position in the string
473     * @return The position of the next character, if the current one is a CHAR.
474     */
475    public static boolean isAlphaDigit( String string, int index )
476    {
477        if ( string == null )
478        {
479            return false;
480        }
481
482        int length = string.length();
483
484        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
485        {
486            return false;
487        }
488        else
489        {
490            char c = string.charAt( index );
491
492            return ( c <= 127 ) && ALPHA_DIGIT[c];
493        }
494    }
495
496
497    /**
498     * Check if the current character is an 7 bits ASCII CHAR (between 0 and
499     * 127). &lt;char&gt; ::= &lt;alpha&gt; | &lt;digit&gt; | '-'
500     *
501     * @param bytes The buffer which contains the data
502     * @param index Current position in the buffer
503     * @return The position of the next character, if the current one is a CHAR.
504     */
505    public static boolean isAlphaDigitMinus( byte[] bytes, int index )
506    {
507        if ( ( bytes == null ) || ( bytes.length == 0 ) || ( index < 0 ) || ( index >= bytes.length ) )
508        {
509            return false;
510        }
511        else
512        {
513            byte c = bytes[index];
514
515            return ( ( c | 0x7F ) == 0x7F ) && CHAR[c];
516        }
517    }
518
519
520    /**
521     * Check if the current character is an 7 bits ASCII CHAR (between 0 and
522     * 127). &lt;char&gt; ::= &lt;alpha&gt; | &lt;digit&gt; | '-'
523     *
524     * @param chars The buffer which contains the data
525     * @param index Current position in the buffer
526     * @return The position of the next character, if the current one is a CHAR.
527     */
528    public static boolean isAlphaDigitMinus( char[] chars, int index )
529    {
530        if ( ( chars == null ) || ( chars.length == 0 ) || ( index < 0 ) || ( index >= chars.length ) )
531        {
532            return false;
533        }
534        else
535        {
536            char c = chars[index];
537
538            return ( c <= 127 ) && CHAR[c];
539        }
540    }
541
542
543    /**
544     * Check if the current character is an 7 bits ASCII CHAR (between 0 and
545     * 127). &lt;char&gt; ::= &lt;alpha&gt; | &lt;digit&gt; | '-'
546     *
547     * @param string The string which contains the data
548     * @param index Current position in the string
549     * @return The position of the next character, if the current one is a CHAR.
550     */
551    public static boolean isAlphaDigitMinus( String string, int index )
552    {
553        if ( string == null )
554        {
555            return false;
556        }
557
558        int length = string.length();
559
560        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
561        {
562            return false;
563        }
564        else
565        {
566            char c = string.charAt( index );
567
568            return ( c <= 127 ) && CHAR[c];
569        }
570    }
571
572
573    /**
574     * Check if the current character is an 7 bits ASCII CHAR (between 0 and
575     * 127). &lt;char&gt; ::= &lt;alpha&gt; | &lt;digit&gt; | '-'
576     *
577     * @param c The char we want to check
578     * @return The position of the next character, if the current one is a CHAR.
579     */
580    public static boolean isAlphaDigitMinus( char c )
581    {
582        return ( ( c & 0x007F ) == c ) && CHAR[c];
583    }
584
585
586    /**
587     * Test if the current character is a bit, ie 0 or 1.
588     *
589     * @param string
590     *            The String which contains the data
591     * @param index
592     *            Current position in the string
593     * @return <code>true</code> if the current character is a bit (0 or 1)
594     */
595    public static boolean isBit( String string, int index )
596    {
597        if ( string == null )
598        {
599            return false;
600        }
601
602        int length = string.length();
603
604        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
605        {
606            return false;
607        }
608        else
609        {
610            char c = string.charAt( index );
611            return ( c == '0' ) || ( c == '1' );
612        }
613    }
614
615
616    /**
617     * Test if the current character is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
618     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
619     *
620     * @param bytes The buffer which contains the data
621     * @return <code>true</code> if the current character is a Digit
622     */
623    public static boolean isDigit( byte[] bytes )
624    {
625        if ( ( bytes == null ) || ( bytes.length == 0 ) )
626        {
627            return false;
628        }
629        else
630        {
631            return ( ( bytes[0] | 0x7F ) == 0x7F ) && DIGIT[bytes[0]];
632        }
633    }
634
635
636    /**
637     * Test if the current character is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
638     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
639     *
640     * @param car the character to test
641     *
642     * @return <code>true</code> if the character is a Digit
643     */
644    public static boolean isDigit( char car )
645    {
646        return ( car >= '0' ) && ( car <= '9' );
647    }
648
649
650    /**
651     * Test if the current byte is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
652     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
653     *
654     * @param car the byte to test
655     *
656     * @return <code>true</code> if the character is a Digit
657     */
658    public static boolean isDigit( byte car )
659    {
660        return ( car >= '0' ) && ( car <= '9' );
661    }
662
663
664    /**
665     * Test if the current character is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
666     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
667     *
668     * @param bytes The buffer which contains the data
669     * @param index Current position in the buffer
670     * @return <code>true</code> if the current character is a Digit
671     */
672    public static boolean isDigit( byte[] bytes, int index )
673    {
674        if ( ( bytes == null ) || ( bytes.length == 0 ) || ( index < 0 ) || ( index >= bytes.length ) )
675        {
676            return false;
677        }
678        else
679        {
680            return ( ( bytes[index] | 0x7F ) == 0x7F ) && DIGIT[bytes[index]];
681        }
682    }
683
684
685    /**
686     * Test if the current character is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
687     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
688     *
689     * @param chars The buffer which contains the data
690     * @param index Current position in the buffer
691     * @return <code>true</code> if the current character is a Digit
692     */
693    public static boolean isDigit( char[] chars, int index )
694    {
695        if ( ( chars == null ) || ( chars.length == 0 ) || ( index < 0 ) || ( index >= chars.length ) )
696        {
697            return false;
698        }
699        else
700        {
701            return ( chars[index] <= 127 ) && DIGIT[chars[index]];
702        }
703    }
704
705
706    /**
707     * Test if the current character is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
708     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
709     *
710     * @param string The string which contains the data
711     * @param index Current position in the string
712     * @return <code>true</code> if the current character is a Digit
713     */
714    public static boolean isDigit( String string, int index )
715    {
716        if ( string == null )
717        {
718            return false;
719        }
720
721        int length = string.length();
722
723        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
724        {
725            return false;
726        }
727        else
728        {
729            char c = string.charAt( index );
730            
731            return ( c <= 127 ) && DIGIT[c];
732        }
733    }
734
735
736    /**
737     * Test if the current character is a digit &lt;digit&gt; ::= '0' | '1' | '2' |
738     * '3' | '4' | '5' | '6' | '7' | '8' | '9'
739     *
740     * @param chars The buffer which contains the data
741     * @return <code>true</code> if the current character is a Digit
742     */
743    public static boolean isDigit( char[] chars )
744    {
745        if ( ( chars == null ) || ( chars.length == 0 ) )
746        {
747            return false;
748        }
749        else
750        {
751            return ( chars[0] <= 127 ) && DIGIT[chars[0]];
752        }
753    }
754
755
756    /**
757     * Check if the current char is an Hex Char
758     * &lt;hex&gt; ::= [0x30-0x39] | [0x41-0x46] | [0x61-0x66]
759     *
760     * @param c The char we want to check
761     * @return <code>true</code> if the current char is a Hex char
762     */
763    public static boolean isHex( char c )
764    {
765        return ( ( c | 0x007F ) == 0x007F ) && HEX[c];
766    }
767
768
769    /**
770     * Check if the current byte is an Hex Char
771     * &lt;hex&gt; ::= [0x30-0x39] | [0x41-0x46] | [0x61-0x66]
772     *
773     * @param b The byte we want to check
774     * @return <code>true</code> if the current byte is a Hex byte
775     */
776    public static boolean isHex( byte b )
777    {
778        return ( ( b | 0x7F ) == 0x7F ) && HEX[b];
779    }
780
781
782    /**
783     * Check if the current character is an Hex Char &lt;hex&gt; ::= [0x30-0x39] |
784     * [0x41-0x46] | [0x61-0x66]
785     *
786     * @param bytes The buffer which contains the data
787     * @param index Current position in the buffer
788     * @return <code>true</code> if the current character is a Hex Char
789     */
790    public static boolean isHex( byte[] bytes, int index )
791    {
792        if ( ( bytes == null ) || ( bytes.length == 0 ) || ( index < 0 ) || ( index >= bytes.length ) )
793        {
794            return false;
795        }
796        else
797        {
798            byte c = bytes[index];
799
800            return ( ( c | 0x7F ) == 0x7F ) && HEX[c];
801        }
802    }
803
804
805    /**
806     * Check if the current character is an Hex Char &lt;hex&gt; ::= [0x30-0x39] |
807     * [0x41-0x46] | [0x61-0x66]
808     *
809     * @param chars The buffer which contains the data
810     * @param index Current position in the buffer
811     * @return <code>true</code> if the current character is a Hex Char
812     */
813    public static boolean isHex( char[] chars, int index )
814    {
815        if ( ( chars == null ) || ( chars.length == 0 ) || ( index < 0 ) || ( index >= chars.length ) )
816        {
817            return false;
818        }
819        else
820        {
821            char c = chars[index];
822
823            return ( ( c | 0x007F ) == 0x007F ) && HEX[c];
824        }
825    }
826
827
828    /**
829     * Check if the current character is an Hex Char &lt;hex&gt; ::= [0x30-0x39] |
830     * [0x41-0x46] | [0x61-0x66]
831     *
832     * @param string The string which contains the data
833     * @param index Current position in the string
834     * @return <code>true</code> if the current character is a Hex Char
835     */
836    public static boolean isHex( String string, int index )
837    {
838        if ( string == null )
839        {
840            return false;
841        }
842
843        int length = string.length();
844
845        if ( ( length == 0 ) || ( index < 0 ) || ( index >= length ) )
846        {
847            return false;
848        }
849        else
850        {
851            char c = string.charAt( index );
852
853            return ( ( c | 0x007F ) == 0x007F ) && HEX[c];
854        }
855    }
856    
857    
858    /**
859     * Check if the current character is the ASCII character underscore 0x5F.
860     *
861     * @param bytes The buffer which contains the data
862     * @param index Current position in the buffer
863     * @return <code>true</code> if the current character is a the underscore
864     */
865    public static boolean isUnderscore( byte[] bytes, int index )
866    {
867        if ( ( bytes == null ) || ( bytes.length == 0 ) || ( index < 0 ) || ( index >= bytes.length ) )
868        {
869            return false;
870        }
871        else
872        {
873            byte c = bytes[index];
874
875            return c == 0x5F;
876        }
877    }
878
879}