API Overview API Index Package Overview Direct link to this page
JDK 1.6
  java.lang. Long View Javadoc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145

/*
 * @(#)Long.java	1.81 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.lang;

/**
 * The <code>Long</code> class wraps a value of the primitive type
 * <code>long</code> in an object. An object of type <code>Long</code>
 * contains a single field whose type is <code>long</code>.
 *
 * <p> 
 *
 * In addition, this class provides several methods for converting a
 * <code>long</code> to a <code>String</code> and a
 * <code>String</code> to a <code>long</code>, as well as other
 * constants and methods useful when dealing with a <code>long</code>.
 *
 * <p>Implementation note: The implementations of the "bit twiddling"
 * methods (such as {@link #highestOneBit(long) highestOneBit} and
 * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are
 * based on material from Henry S. Warren, Jr.'s <i>Hacker's
 * Delight</i>, (Addison Wesley, 2002).
 *
 * @author  Lee Boynton
 * @author  Arthur van Hoff
 * @author  Josh Bloch
 * @version 1.81, 11/17/05
 * @since   JDK1.0
 */
public final class Long extends Number implements Comparable<Long> {
    /**
     * A constant holding the minimum value a <code>long</code> can
     * have, -2<sup>63</sup>.
     */
    public static final long MIN_VALUE = 0x8000000000000000L;

    /**
     * A constant holding the maximum value a <code>long</code> can
     * have, 2<sup>63</sup>-1.
     */
    public static final long MAX_VALUE = 0x7fffffffffffffffL;

    /**
     * The <code>Class</code> instance representing the primitive type
     * <code>long</code>.
     *
     * @since   JDK1.1
     */
    public static final Class<Long>	TYPE = (Class<Long>) Class.getPrimitiveClass("long");

    /**
     * Returns a string representation of the first argument in the
     * radix specified by the second argument.
     * <p>
     * If the radix is smaller than <code>Character.MIN_RADIX</code>
     * or larger than <code>Character.MAX_RADIX</code>, then the radix
     * <code>10</code> is used instead.
     * <p>
     * If the first argument is negative, the first element of the
     * result is the ASCII minus sign <code>'-'</code>
     * (<code>'&#92;u002d'</code>). If the first argument is not
     * negative, no sign character appears in the result.
     * <p>
     * The remaining characters of the result represent the magnitude
     * of the first argument. If the magnitude is zero, it is
     * represented by a single zero character <code>'0'</code>
     * (<code>'&#92;u0030'</code>); otherwise, the first character of
     * the representation of the magnitude will not be the zero
     * character.  The following ASCII characters are used as digits:
     * <blockquote><pre>
     *   0123456789abcdefghijklmnopqrstuvwxyz
     * </pre></blockquote>
     * These are <code>'&#92;u0030'</code> through
     * <code>'&#92;u0039'</code> and <code>'&#92;u0061'</code> through
     * <code>'&#92;u007a'</code>. If <code>radix</code> is
     * <var>N</var>, then the first <var>N</var> of these characters
     * are used as radix-<var>N</var> digits in the order shown. Thus,
     * the digits for hexadecimal (radix 16) are
     * <code>0123456789abcdef</code>. If uppercase letters are
     * desired, the {@link java.lang.String#toUpperCase()} method may
     * be called on the result:
     * <blockquote><pre>
     * Long.toString(n, 16).toUpperCase()
     * </pre></blockquote>
     * 
     * @param   i       a <code>long</code>to be converted to a string.
     * @param   radix   the radix to use in the string representation.
     * @return  a string representation of the argument in the specified radix.
     * @see     java.lang.Character#MAX_RADIX
     * @see     java.lang.Character#MIN_RADIX
     */
    public static String toString(long i, int radix) {
        if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
	    radix = 10;
        if (radix == 10)
            return toString(i);
        char[] buf = new char[65];
        int charPos = 64;
        boolean negative = (i < 0);

        if (!negative) {
            i = -i;
        }

        while (i <= -radix) {
            buf[charPos--] = Integer.digits[(int)(-(i % radix))];
            i = i / radix;
        }
        buf[charPos] = Integer.digits[(int)(-i)];

        if (negative) { 
            buf[--charPos] = '-';
        }

        return new String(buf, charPos, (65 - charPos));
    }

    /**
     * Returns a string representation of the <code>long</code>
     * argument as an unsigned integer in base&nbsp;16.
     * <p>
     * The unsigned <code>long</code> value is the argument plus
     * 2<sup>64</sup> if the argument is negative; otherwise, it is
     * equal to the argument.  This value is converted to a string of
     * ASCII digits in hexadecimal (base&nbsp;16) with no extra
     * leading <code>0</code>s.  If the unsigned magnitude is zero, it
     * is represented by a single zero character <code>'0'</code>
     * (<code>'&#92;u0030'</code>); otherwise, the first character of
     * the representation of the unsigned magnitude will not be the
     * zero character. The following characters are used as
     * hexadecimal digits:
     * <blockquote><pre>
     * 0123456789abcdef
     * </pre></blockquote>
     * These are the characters <code>'&#92;u0030'</code> through
     * <code>'&#92;u0039'</code> and  <code>'&#92;u0061'</code> through
     * <code>'&#92;u0066'</code>.  If uppercase letters are desired,
     * the {@link java.lang.String#toUpperCase()} method may be called
     * on the result:
     * <blockquote><pre>
     * Long.toHexString(n).toUpperCase()
     * </pre></blockquote>
     *
     * @param   i   a <code>long</code> to be converted to a string.
     * @return  the string representation of the unsigned <code>long</code>
     * 		value represented by the argument in hexadecimal
     *		(base&nbsp;16).
     * @since   JDK 1.0.2
     */
    public static String toHexString(long i) {
	return toUnsignedString(i, 4);
    }

    /**
     * Returns a string representation of the <code>long</code>
     * argument as an unsigned integer in base&nbsp;8.
     * <p>
     * The unsigned <code>long</code> value is the argument plus
     * 2<sup>64</sup> if the argument is negative; otherwise, it is
     * equal to the argument.  This value is converted to a string of
     * ASCII digits in octal (base&nbsp;8) with no extra leading
     * <code>0</code>s.
     * <p>
     * If the unsigned magnitude is zero, it is represented by a
     * single zero character <code>'0'</code>
     * (<code>'&#92;u0030'</code>); otherwise, the first character of
     * the representation of the unsigned magnitude will not be the
     * zero character. The following characters are used as octal
     * digits:
     * <blockquote><pre>
     * 01234567
     * </pre></blockquote>
     * These are the characters <code>'&#92;u0030'</code> through 
     * <code>'&#92;u0037'</code>. 
     *
     * @param   i   a <code>long</code> to be converted to a string.
     * @return  the string representation of the unsigned <code>long</code> 
     *		value represented by the argument in octal (base&nbsp;8).
     * @since   JDK 1.0.2
     */
    public static String toOctalString(long i) {
	return toUnsignedString(i, 3);
    }

    /**
     * Returns a string representation of the <code>long</code>
     * argument as an unsigned integer in base&nbsp;2.
     * <p>
     * The unsigned <code>long</code> value is the argument plus
     * 2<sup>64</sup> if the argument is negative; otherwise, it is
     * equal to the argument.  This value is converted to a string of
     * ASCII digits in binary (base&nbsp;2) with no extra leading
     * <code>0</code>s.  If the unsigned magnitude is zero, it is
     * represented by a single zero character <code>'0'</code>
     * (<code>'&#92;u0030'</code>); otherwise, the first character of
     * the representation of the unsigned magnitude will not be the
     * zero character. The characters <code>'0'</code>
     * (<code>'&#92;u0030'</code>) and <code>'1'</code>
     * (<code>'&#92;u0031'</code>) are used as binary digits.
     *
     * @param   i   a <code>long</code> to be converted to a string.
     * @return  the string representation of the unsigned <code>long</code> 
     *          value represented by the argument in binary (base&nbsp;2).
     * @since   JDK 1.0.2
     */
    public static String toBinaryString(long i) {
	return toUnsignedString(i, 1);
    }

    /**
     * Convert the integer to an unsigned number.
     */
    private static String toUnsignedString(long i, int shift) {
	char[] buf = new char[64];
	int charPos = 64;
	int radix = 1 << shift;
	long mask = radix - 1;
	do {
	    buf[--charPos] = Integer.digits[(int)(i & mask)];
	    i >>>= shift;
	} while (i != 0);
	return new String(buf, charPos, (64 - charPos));
    }

    /**
     * Returns a <code>String</code> object representing the specified
     * <code>long</code>.  The argument is converted to signed decimal
     * representation and returned as a string, exactly as if the
     * argument and the radix 10 were given as arguments to the {@link
     * #toString(long, int)} method.
     *
     * @param   i   a <code>long</code> to be converted.
     * @return  a string representation of the argument in base&nbsp;10.
     */
    public static String toString(long i) {
        if (i == Long.MIN_VALUE)
            return "-9223372036854775808";
        int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
        char[] buf = new char[size];
        getChars(i, size, buf);
        return new String(0, size, buf);
    }

    /**
     * Places characters representing the integer i into the
     * character array buf. The characters are placed into
     * the buffer backwards starting with the least significant
     * digit at the specified index (exclusive), and working
     * backwards from there.
     *
     * Will fail if i == Long.MIN_VALUE
     */
    static void getChars(long i, int index, char[] buf) {
        long q;
        int r;
        int charPos = index;
        char sign = 0;

        if (i < 0) {
            sign = '-';
            i = -i;
        }

        // Get 2 digits/iteration using longs until quotient fits into an int
        while (i > Integer.MAX_VALUE) { 
            q = i / 100;
            // really: r = i - (q * 100);
            r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
            i = q;
            buf[--charPos] = Integer.DigitOnes[r];
            buf[--charPos] = Integer.DigitTens[r];
        }

        // Get 2 digits/iteration using ints
        int q2;
        int i2 = (int)i;
        while (i2 >= 65536) {
            q2 = i2 / 100;
            // really: r = i2 - (q * 100);
            r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
            i2 = q2;
            buf[--charPos] = Integer.DigitOnes[r];
            buf[--charPos] = Integer.DigitTens[r];
        }

        // Fall thru to fast mode for smaller numbers
        // assert(i2 <= 65536, i2);
        for (;;) {
            q2 = (i2 * 52429) >>> (16+3);
            r = i2 - ((q2 << 3) + (q2 << 1));  // r = i2-(q2*10) ...
            buf[--charPos] = Integer.digits[r];
            i2 = q2;
            if (i2 == 0) break;
        }
        if (sign != 0) {
            buf[--charPos] = sign;
        }
    }

    // Requires positive x
    static int stringSize(long x) {
        long p = 10;
        for (int i=1; i<19; i++) {
            if (x < p)
                return i;
            p = 10*p;
        }
        return 19;
    }

    /**
     * Parses the string argument as a signed <code>long</code> in the
     * radix specified by the second argument. The characters in the
     * string must all be digits of the specified radix (as determined
     * by whether {@link java.lang.Character#digit(char, int)} returns
     * a nonnegative value), except that the first character may be an
     * ASCII minus sign <code>'-'</code> (<code>'&#92;u002D'</code>) to
     * indicate a negative value. The resulting <code>long</code>
     * value is returned.
     * <p>
     * Note that neither the character <code>L</code>
     * (<code>'&#92;u004C'</code>) nor <code>l</code>
     * (<code>'&#92;u006C'</code>) is permitted to appear at the end
     * of the string as a type indicator, as would be permitted in
     * Java programming language source code - except that either
     * <code>L</code> or <code>l</code> may appear as a digit for a
     * radix greater than 22.
     * <p>
     * An exception of type <code>NumberFormatException</code> is
     * thrown if any of the following situations occurs:
     * <ul>
     * <li>The first argument is <code>null</code> or is a string of
     * length zero.
     * <li>The <code>radix</code> is either smaller than {@link
     * java.lang.Character#MIN_RADIX} or larger than {@link
     * java.lang.Character#MAX_RADIX}.
     * <li>Any character of the string is not a digit of the specified
     * radix, except that the first character may be a minus sign
     * <code>'-'</code> (<code>'&#92;u002d'</code>) provided that the
     * string is longer than length 1.
     * <li>The value represented by the string is not a value of type
     *      <code>long</code>. 
     * </ul><p>
     * Examples:
     * <blockquote><pre>
     * parseLong("0", 10) returns 0L
     * parseLong("473", 10) returns 473L
     * parseLong("-0", 10) returns 0L
     * parseLong("-FF", 16) returns -255L
     * parseLong("1100110", 2) returns 102L
     * parseLong("99", 8) throws a NumberFormatException
     * parseLong("Hazelnut", 10) throws a NumberFormatException
     * parseLong("Hazelnut", 36) returns 1356099454469L
     * </pre></blockquote>
     * 
     * @param      s       the <code>String</code> containing the
     *                     <code>long</code> representation to be parsed.
     * @param      radix   the radix to be used while parsing <code>s</code>.
     * @return     the <code>long</code> represented by the string argument in
     *             the specified radix.
     * @exception  NumberFormatException  if the string does not contain a
     *               parsable <code>long</code>.
     */
    public static long parseLong(String s, int radix)
              throws NumberFormatException
    {
        if (s == null) {
            throw new NumberFormatException("null");
        }

	if (radix < Character.MIN_RADIX) {
	    throw new NumberFormatException("radix " + radix +
					    " less than Character.MIN_RADIX");
	}
	if (radix > Character.MAX_RADIX) {
	    throw new NumberFormatException("radix " + radix +
					    " greater than Character.MAX_RADIX");
	}

	long result = 0;
	boolean negative = false;
	int i = 0, max = s.length();
	long limit;
	long multmin;
	int digit;

	if (max > 0) {
	    if (s.charAt(0) == '-') {
		negative = true;
		limit = Long.MIN_VALUE;
		i++;
	    } else {
		limit = -Long.MAX_VALUE;
	    }
	    multmin = limit / radix;
            if (i < max) {
                digit = Character.digit(s.charAt(i++),radix);
		if (digit < 0) {
		    throw NumberFormatException.forInputString(s);
		} else {
		    result = -digit;
		}
	    }
	    while (i < max) {
		// Accumulating negatively avoids surprises near MAX_VALUE
		digit = Character.digit(s.charAt(i++),radix);
		if (digit < 0) {
		    throw NumberFormatException.forInputString(s);
		}
		if (result < multmin) {
		    throw NumberFormatException.forInputString(s);
		}
		result *= radix;
		if (result < limit + digit) {
		    throw NumberFormatException.forInputString(s);
		}
		result -= digit;
	    }
	} else {
	    throw NumberFormatException.forInputString(s);
	}
	if (negative) {
	    if (i > 1) {
		return result;
	    } else {	/* Only got "-" */
		throw NumberFormatException.forInputString(s);
	    }
	} else {
	    return -result;
	}
    }

    /**
     * Parses the string argument as a signed decimal
     * <code>long</code>.  The characters in the string must all be
     * decimal digits, except that the first character may be an ASCII
     * minus sign <code>'-'</code> (<code>&#92;u002D'</code>) to
     * indicate a negative value. The resulting <code>long</code>
     * value is returned, exactly as if the argument and the radix
     * <code>10</code> were given as arguments to the {@link
     * #parseLong(java.lang.String, int)} method.
     * <p>
     * Note that neither the character <code>L</code>
     * (<code>'&#92;u004C'</code>) nor <code>l</code>
     * (<code>'&#92;u006C'</code>) is permitted to appear at the end
     * of the string as a type indicator, as would be permitted in
     * Java programming language source code.
     *
     * @param      s   a <code>String</code> containing the <code>long</code>
     *             representation to be parsed
     * @return     the <code>long</code> represented by the argument in 
     *		   decimal.
     * @exception  NumberFormatException  if the string does not contain a
     *               parsable <code>long</code>.
     */
    public static long parseLong(String s) throws NumberFormatException {
	return parseLong(s, 10);
    }

    /**
     * Returns a <code>Long</code> object holding the value
     * extracted from the specified <code>String</code> when parsed
     * with the radix given by the second argument.  The first
     * argument is interpreted as representing a signed
     * <code>long</code> in the radix specified by the second
     * argument, exactly as if the arguments were given to the {@link
     * #parseLong(java.lang.String, int)} method. The result is a
     * <code>Long</code> object that represents the <code>long</code>
     * value specified by the string.
     * <p>
     * In other words, this method returns a <code>Long</code> object equal 
     * to the value of:
     *
     * <blockquote><code>
     * new Long(Long.parseLong(s, radix))
     * </code></blockquote>
     *
     * @param      s       the string to be parsed
     * @param      radix   the radix to be used in interpreting <code>s</code>
     * @return     a <code>Long</code> object holding the value
     *             represented by the string argument in the specified
     *             radix.
     * @exception  NumberFormatException  If the <code>String</code> does not
     *             contain a parsable <code>long</code>.
     */
    public static Long valueOf(String s, int radix) throws NumberFormatException {
	return new Long(parseLong(s, radix));
    }

    /**
     * Returns a <code>Long</code> object holding the value
     * of the specified <code>String</code>. The argument is
     * interpreted as representing a signed decimal <code>long</code>,
     * exactly as if the argument were given to the {@link
     * #parseLong(java.lang.String)} method. The result is a
     * <code>Long</code> object that represents the integer value
     * specified by the string.
     * <p>
     * In other words, this method returns a <code>Long</code> object
     * equal to the value of:
     *
     * <blockquote><pre>
     * new Long(Long.parseLong(s))
     * </pre></blockquote>
     *
     * @param      s   the string to be parsed.
     * @return     a <code>Long</code> object holding the value
     *             represented by the string argument.
     * @exception  NumberFormatException  If the string cannot be parsed
     *              as a <code>long</code>.
     */
    public static Long valueOf(String s) throws NumberFormatException
    {
	return new Long(parseLong(s, 10));
    }

    private static class LongCache {
	private LongCache(){}

	static final Long cache[] = new Long[-(-128) + 127 + 1];

	static {
	    for(int i = 0; i < cache.length; i++)
		cache[i] = new Long(i - 128);
	}
    }

    /**
     * Returns a <tt>Long</tt> instance representing the specified
     * <tt>long</tt> value.
     * If a new <tt>Long</tt> instance is not required, this method
     * should generally be used in preference to the constructor
     * {@link #Long(long)}, as this method is likely to yield
     * significantly better space and time performance by caching
     * frequently requested values.
     *
     * @param  l a long value.
     * @return a <tt>Long</tt> instance representing <tt>l</tt>.
     * @since  1.5
     */
    public static Long valueOf(long l) {
	final int offset = 128;
	if (l >= -128 && l <= 127) { // will cache
	    return LongCache.cache[(int)l + offset];
	}
        return new Long(l);
    }

    /**
     * Decodes a <code>String</code> into a <code>Long</code>.
     * Accepts decimal, hexadecimal, and octal numbers given by the
     * following grammar:
     *
     * <blockquote>
     * <dl>
     * <dt><i>DecodableString:</i>
     * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
     * <dd><i>Sign<sub>opt</sub></i> <code>0x</code> <i>HexDigits</i>
     * <dd><i>Sign<sub>opt</sub></i> <code>0X</code> <i>HexDigits</i>
     * <dd><i>Sign<sub>opt</sub></i> <code>#</code> <i>HexDigits</i>
     * <dd><i>Sign<sub>opt</sub></i> <code>0</code> <i>OctalDigits</i>
     * <p>
     * <dt><i>Sign:</i>
     * <dd><code>-</code>
     * </dl>
     * </blockquote>
     *
     * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
     * are defined in <a href="http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#48282">&sect;3.10.1</a> 
     * of the <a href="http://java.sun.com/docs/books/jls/html/">Java 
     * Language Specification</a>.
     * <p>
     * The sequence of characters following an (optional) negative
     * sign and/or radix specifier (&quot;<code>0x</code>&quot;,
     * &quot;<code>0X</code>&quot;, &quot;<code>#</code>&quot;, or
     * leading zero) is parsed as by the <code>Long.parseLong</code>
     * method with the indicated radix (10, 16, or 8).  This sequence
     * of characters must represent a positive value or a {@link
     * NumberFormatException} will be thrown.  The result is negated
     * if first character of the specified <code>String</code> is the
     * minus sign.  No whitespace characters are permitted in the
     * <code>String</code>.
     *
     * @param     nm the <code>String</code> to decode.
     * @return    a <code>Long</code> object holding the <code>long</code>
     *		  value represented by <code>nm</code>
     * @exception NumberFormatException  if the <code>String</code> does not
     *            contain a parsable <code>long</code>.
     * @see java.lang.Long#parseLong(String, int)
     * @since 1.2
     */
    public static Long decode(String nm) throws NumberFormatException {
        int radix = 10;
        int index = 0;
        boolean negative = false;
        Long result;

        // Handle minus sign, if present
        if (nm.startsWith("-")) {
            negative = true;
            index++;
        }

        // Handle radix specifier, if present
	if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
	    index += 2;
            radix = 16;
	}
	else if (nm.startsWith("#", index)) {
	    index ++;
            radix = 16;
	}
	else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
	    index ++;
            radix = 8;
	}

        if (nm.startsWith("-", index))
            throw new NumberFormatException("Negative sign in wrong position");

        try {
            result = Long.valueOf(nm.substring(index), radix);
            result = negative ? new Long((long)-result.longValue()) : result;
        } catch (NumberFormatException e) {
            // If number is Long.MIN_VALUE, we'll end up here. The next line
            // handles this case, and causes any genuine format error to be
            // rethrown.
            String constant = negative ? new String("-" + nm.substring(index))
                                       : nm.substring(index);
            result = Long.valueOf(constant, radix);
        }
        return result;
    }

    /**
     * The value of the <code>Long</code>.
     *
     * @serial
     */
    private final long value;

    /**
     * Constructs a newly allocated <code>Long</code> object that
     * represents the specified <code>long</code> argument.
     *
     * @param   value   the value to be represented by the 
     *          <code>Long</code> object.
     */
    public Long(long value) {
	this.value = value;
    }

    /**
     * Constructs a newly allocated <code>Long</code> object that
     * represents the <code>long</code> value indicated by the
     * <code>String</code> parameter. The string is converted to a
     * <code>long</code> value in exactly the manner used by the
     * <code>parseLong</code> method for radix 10.
     *
     * @param      s   the <code>String</code> to be converted to a 
     *		   <code>Long</code>.
     * @exception  NumberFormatException  if the <code>String</code> does not
     *               contain a parsable <code>long</code>.
     * @see        java.lang.Long#parseLong(java.lang.String, int)
     */
    public Long(String s) throws NumberFormatException {
	this.value = parseLong(s, 10);
    }

    /**
     * Returns the value of this <code>Long</code> as a
     * <code>byte</code>.
     */
    public byte byteValue() {
	return (byte)value;
    }

    /**
     * Returns the value of this <code>Long</code> as a
     * <code>short</code>.
     */
    public short shortValue() {
	return (short)value;
    }

    /**
     * Returns the value of this <code>Long</code> as an
     * <code>int</code>.
     */
    public int intValue() {
	return (int)value;
    }

    /**
     * Returns the value of this <code>Long</code> as a
     * <code>long</code> value.
     */
    public long longValue() {
	return (long)value;
    }

    /**
     * Returns the value of this <code>Long</code> as a
     * <code>float</code>.
     */
    public float floatValue() {
	return (float)value;
    }

    /**
     * Returns the value of this <code>Long</code> as a
     * <code>double</code>.
     */
    public double doubleValue() {
	return (double)value;
    }

    /**
     * Returns a <code>String</code> object representing this
     * <code>Long</code>'s value.  The value is converted to signed
     * decimal representation and returned as a string, exactly as if
     * the <code>long</code> value were given as an argument to the
     * {@link java.lang.Long#toString(long)} method.
     *
     * @return  a string representation of the value of this object in
     *		base&nbsp;10.
     */
    public String toString() {
	return String.valueOf(value);
    }

    /**
     * Returns a hash code for this <code>Long</code>. The result is
     * the exclusive OR of the two halves of the primitive
     * <code>long</code> value held by this <code>Long</code>
     * object. That is, the hashcode is the value of the expression:
     * <blockquote><pre>
     * (int)(this.longValue()^(this.longValue()&gt;&gt;&gt;32))
     * </pre></blockquote>
     *
     * @return  a hash code value for this object.
     */
    public int hashCode() {
	return (int)(value ^ (value >>> 32));
    }

    /**
     * Compares this object to the specified object.  The result is
     * <code>true</code> if and only if the argument is not
     * <code>null</code> and is a <code>Long</code> object that
     * contains the same <code>long</code> value as this object.
     *
     * @param   obj   the object to compare with.
     * @return  <code>true</code> if the objects are the same;
     *          <code>false</code> otherwise.
     */
    public boolean equals(Object obj) {
	if (obj instanceof Long) {
	    return value == ((Long)obj).longValue();
	}
	return false;
    }

    /**
     * Determines the <code>long</code> value of the system property
     * with the specified name.
     * <p>
     * The first argument is treated as the name of a system property.
     * System properties are accessible through the {@link
     * java.lang.System#getProperty(java.lang.String)} method. The
     * string value of this property is then interpreted as a
     * <code>long</code> value and a <code>Long</code> object
     * representing this value is returned.  Details of possible
     * numeric formats can be found with the definition of
     * <code>getProperty</code>.
     * <p>
     * If there is no property with the specified name, if the
     * specified name is empty or <code>null</code>, or if the
     * property does not have the correct numeric format, then
     * <code>null</code> is returned.
     * <p>
     * In other words, this method returns a <code>Long</code> object equal to 
     * the value of:
     * <blockquote><code>
     * getLong(nm, null)
     * </code></blockquote>
     *
     * @param   nm   property name.
     * @return  the <code>Long</code> value of the property.
     * @see     java.lang.System#getProperty(java.lang.String)
     * @see     java.lang.System#getProperty(java.lang.String, java.lang.String)
     */
    public static Long getLong(String nm) {
	return getLong(nm, null);
    }

    /**
     * Determines the <code>long</code> value of the system property
     * with the specified name.
     * <p>
     * The first argument is treated as the name of a system property.
     * System properties are accessible through the {@link
     * java.lang.System#getProperty(java.lang.String)} method. The
     * string value of this property is then interpreted as a
     * <code>long</code> value and a <code>Long</code> object
     * representing this value is returned.  Details of possible
     * numeric formats can be found with the definition of
     * <code>getProperty</code>.
     * <p>
     * The second argument is the default value. A <code>Long</code> object
     * that represents the value of the second argument is returned if there
     * is no property of the specified name, if the property does not have
     * the correct numeric format, or if the specified name is empty or null.
     * <p>
     * In other words, this method returns a <code>Long</code> object equal 
     * to the value of:
     * <blockquote><code>
     * getLong(nm, new Long(val))
     * </code></blockquote>
     * but in practice it may be implemented in a manner such as: 
     * <blockquote><pre>
     * Long result = getLong(nm, null);
     * return (result == null) ? new Long(val) : result;
     * </pre></blockquote>
     * to avoid the unnecessary allocation of a <code>Long</code> object when 
     * the default value is not needed. 
     *
     * @param   nm    property name.
     * @param   val   default value.
     * @return  the <code>Long</code> value of the property.
     * @see     java.lang.System#getProperty(java.lang.String)
     * @see     java.lang.System#getProperty(java.lang.String, java.lang.String)
     */
    public static Long getLong(String nm, long val) {
        Long result = Long.getLong(nm, null);
        return (result == null) ? new Long(val) : result;
    }

    /**
     * Returns the <code>long</code> value of the system property with
     * the specified name.  The first argument is treated as the name
     * of a system property.  System properties are accessible through
     * the {@link java.lang.System#getProperty(java.lang.String)}
     * method. The string value of this property is then interpreted
     * as a <code>long</code> value, as per the
     * <code>Long.decode</code> method, and a <code>Long</code> object
     * representing this value is returned.
     * <p><ul>
     * <li>If the property value begins with the two ASCII characters
     * <code>0x</code> or the ASCII character <code>#</code>, not followed by 
     * a minus sign, then the rest of it is parsed as a hexadecimal integer
     * exactly as for the method {@link #valueOf(java.lang.String, int)} 
     * with radix 16. 
     * <li>If the property value begins with the ASCII character
     * <code>0</code> followed by another character, it is parsed as
     * an octal integer exactly as by the method {@link
     * #valueOf(java.lang.String, int)} with radix 8.
     * <li>Otherwise the property value is parsed as a decimal
     * integer exactly as by the method 
     * {@link #valueOf(java.lang.String, int)} with radix 10.
     * </ul>
     * <p>
     * Note that, in every case, neither <code>L</code>
     * (<code>'&#92;u004C'</code>) nor <code>l</code>
     * (<code>'&#92;u006C'</code>) is permitted to appear at the end
     * of the property value as a type indicator, as would be
     * permitted in Java programming language source code.
     * <p>
     * The second argument is the default value. The default value is
     * returned if there is no property of the specified name, if the
     * property does not have the correct numeric format, or if the
     * specified name is empty or <code>null</code>.
     *
     * @param   nm   property name.
     * @param   val   default value.
     * @return  the <code>Long</code> value of the property.
     * @see     java.lang.System#getProperty(java.lang.String)
     * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
     * @see java.lang.Long#decode
     */
    public static Long getLong(String nm, Long val) {
        String v = null;
        try {
            v = System.getProperty(nm);
        } catch (IllegalArgumentException e) {
        } catch (NullPointerException e) {
        }
	if (v != null) {
	    try {
		return Long.decode(v);
	    } catch (NumberFormatException e) {
	    }
	}
	return val;
    }

    /**
     * Compares two <code>Long</code> objects numerically.
     *
     * @param   anotherLong   the <code>Long</code> to be compared.
     * @return	the value <code>0</code> if this <code>Long</code> is
     * 		equal to the argument <code>Long</code>; a value less than
     * 		<code>0</code> if this <code>Long</code> is numerically less
     * 		than the argument <code>Long</code>; and a value greater 
     * 		than <code>0</code> if this <code>Long</code> is numerically
     * 		 greater than the argument <code>Long</code> (signed
     * 		 comparison).
     * @since   1.2
     */
    public int compareTo(Long anotherLong) {
	long thisVal = this.value;
	long anotherVal = anotherLong.value;
	return (thisVal<anotherVal ? -1 : (thisVal==anotherVal ? 0 : 1));
    }


    // Bit Twiddling

    /**
     * The number of bits used to represent a <tt>long</tt> value in two's
     * complement binary form.
     *
     * @since 1.5
     */
    public static final int SIZE = 64;
 
    /**
     * Returns a <tt>long</tt> value with at most a single one-bit, in the
     * position of the highest-order ("leftmost") one-bit in the specified
     * <tt>long</tt> value.  Returns zero if the specified value has no
     * one-bits in its two's complement binary representation, that is, if it
     * is equal to zero.
     *
     * @return a <tt>long</tt> value with a single one-bit, in the position
     *     of the highest-order one-bit in the specified value, or zero if
     *     the specified value is itself equal to zero.
     * @since 1.5
     */
    public static long highestOneBit(long i) {
        // HD, Figure 3-1
        i |= (i >>  1);
        i |= (i >>  2);
        i |= (i >>  4);
        i |= (i >>  8);
        i |= (i >> 16);
        i |= (i >> 32);
        return i - (i >>> 1);
    }

    /**
     * Returns a <tt>long</tt> value with at most a single one-bit, in the
     * position of the lowest-order ("rightmost") one-bit in the specified
     * <tt>long</tt> value.  Returns zero if the specified value has no
     * one-bits in its two's complement binary representation, that is, if it
     * is equal to zero.
     *
     * @return a <tt>long</tt> value with a single one-bit, in the position
     *     of the lowest-order one-bit in the specified value, or zero if
     *     the specified value is itself equal to zero.
     * @since 1.5
     */
    public static long lowestOneBit(long i) {
        // HD, Section 2-1
        return i & -i;
    }
 
    /**
     * Returns the number of zero bits preceding the highest-order
     * ("leftmost") one-bit in the two's complement binary representation
     * of the specified <tt>long</tt> value.  Returns 64 if the
     * specified value has no one-bits in its two's complement representation,
     * in other words if it is equal to zero.
     *
     * <p>Note that this method is closely related to the logarithm base 2.
     * For all positive <tt>long</tt> values x:
     * <ul>
     * <li>floor(log<sub>2</sub>(x)) = <tt>63 - numberOfLeadingZeros(x)</tt>
     * <li>ceil(log<sub>2</sub>(x)) = <tt>64 - numberOfLeadingZeros(x - 1)</tt>
     * </ul>
     *
     * @return the number of zero bits preceding the highest-order
     *     ("leftmost") one-bit in the two's complement binary representation
     *     of the specified <tt>long</tt> value, or 64 if the value
     *     is equal to zero.
     * @since 1.5
     */
    public static int numberOfLeadingZeros(long i) {
        // HD, Figure 5-6
         if (i == 0)
            return 64;
        int n = 1;
	int x = (int)(i >>> 32);
        if (x == 0) { n += 32; x = (int)i; }
        if (x >>> 16 == 0) { n += 16; x <<= 16; }
        if (x >>> 24 == 0) { n +=  8; x <<=  8; }
        if (x >>> 28 == 0) { n +=  4; x <<=  4; }
        if (x >>> 30 == 0) { n +=  2; x <<=  2; }
        n -= x >>> 31;
        return n;
    }
 
    /**
     * Returns the number of zero bits following the lowest-order ("rightmost")
     * one-bit in the two's complement binary representation of the specified
     * <tt>long</tt> value.  Returns 64 if the specified value has no
     * one-bits in its two's complement representation, in other words if it is
     * equal to zero.
     *
     * @return the number of zero bits following the lowest-order ("rightmost")
     *     one-bit in the two's complement binary representation of the
     *     specified <tt>long</tt> value, or 64 if the value is equal
     *     to zero.
     * @since 1.5
     */
    public static int numberOfTrailingZeros(long i) {
        // HD, Figure 5-14
	int x, y;
	if (i == 0) return 64;
	int n = 63;
	y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
	y = x <<16; if (y != 0) { n = n -16; x = y; }
	y = x << 8; if (y != 0) { n = n - 8; x = y; }
	y = x << 4; if (y != 0) { n = n - 4; x = y; }
	y = x << 2; if (y != 0) { n = n - 2; x = y; }
	return n - ((x << 1) >>> 31);
    }

    /**
     * Returns the number of one-bits in the two's complement binary
     * representation of the specified <tt>long</tt> value.  This function is
     * sometimes referred to as the <i>population count</i>.
     *
     * @return the number of one-bits in the two's complement binary
     *     representation of the specified <tt>long</tt> value.
     * @since 1.5
     */
     public static int bitCount(long i) {
        // HD, Figure 5-14
	i = i - ((i >>> 1) & 0x5555555555555555L);
	i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
	i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
	i = i + (i >>> 8);
	i = i + (i >>> 16);
	i = i + (i >>> 32);
	return (int)i & 0x7f;
     }
 
    /**
     * Returns the value obtained by rotating the two's complement binary
     * representation of the specified <tt>long</tt> value left by the
     * specified number of bits.  (Bits shifted out of the left hand, or
     * high-order, side reenter on the right, or low-order.)
     *
     * <p>Note that left rotation with a negative distance is equivalent to
     * right rotation: <tt>rotateLeft(val, -distance) == rotateRight(val,
     * distance)</tt>.  Note also that rotation by any multiple of 64 is a
     * no-op, so all but the last six bits of the rotation distance can be
     * ignored, even if the distance is negative: <tt>rotateLeft(val,
     * distance) == rotateLeft(val, distance & 0x3F)</tt>.
     *
     * @return the value obtained by rotating the two's complement binary
     *     representation of the specified <tt>long</tt> value left by the
     *     specified number of bits.
     * @since 1.5
     */
    public static long rotateLeft(long i, int distance) {
        return (i << distance) | (i >>> -distance);
    }
 
    /**
     * Returns the value obtained by rotating the two's complement binary
     * representation of the specified <tt>long</tt> value right by the
     * specified number of bits.  (Bits shifted out of the right hand, or
     * low-order, side reenter on the left, or high-order.)
     *
     * <p>Note that right rotation with a negative distance is equivalent to
     * left rotation: <tt>rotateRight(val, -distance) == rotateLeft(val,
     * distance)</tt>.  Note also that rotation by any multiple of 64 is a
     * no-op, so all but the last six bits of the rotation distance can be
     * ignored, even if the distance is negative: <tt>rotateRight(val,
     * distance) == rotateRight(val, distance & 0x3F)</tt>.
     *
     * @return the value obtained by rotating the two's complement binary
     *     representation of the specified <tt>long</tt> value right by the
     *     specified number of bits.
     * @since 1.5
     */
    public static long rotateRight(long i, int distance) {
        return (i >>> distance) | (i << -distance);
    }
 
    /**
     * Returns the value obtained by reversing the order of the bits in the
     * two's complement binary representation of the specified <tt>long</tt>
     * value.
     *
     * @return the value obtained by reversing order of the bits in the
     *     specified <tt>long</tt> value.
     * @since 1.5
     */
    public static long reverse(long i) {
        // HD, Figure 7-1
	i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
	i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
	i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
	i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
	i = (i << 48) | ((i & 0xffff0000L) << 16) |
	    ((i >>> 16) & 0xffff0000L) | (i >>> 48);
	return i;
    }
 
    /**
     * Returns the signum function of the specified <tt>long</tt> value.  (The
     * return value is -1 if the specified value is negative; 0 if the
     * specified value is zero; and 1 if the specified value is positive.)
     *
     * @return the signum function of the specified <tt>long</tt> value.
     * @since 1.5
     */
    public static int signum(long i) {
        // HD, Section 2-7
        return (int) ((i >> 63) | (-i >>> 63));
    }
 
    /**
     * Returns the value obtained by reversing the order of the bytes in the
     * two's complement representation of the specified <tt>long</tt> value.
     *
     * @return the value obtained by reversing the bytes in the specified
     *     <tt>long</tt> value.
     * @since 1.5
     */
    public static long reverseBytes(long i) {
        i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
        return (i << 48) | ((i & 0xffff0000L) << 16) |
            ((i >>> 16) & 0xffff0000L) | (i >>> 48);
    }

    /** use serialVersionUID from JDK 1.0.2 for interoperability */
    private static final long serialVersionUID = 4290774380558885855L;
}

Generated By: JavaOnTracks Doclet 0.1.4     ©Thibaut Colar