1 /*
2 * Copyright (c) 1994, 2013, 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 java.lang;
27
28 import java.lang.annotation.Native;
29 import java.math.*;
30 import java.util.Objects;
31 import jdk.internal.HotSpotIntrinsicCandidate;
32
33 import static java.lang.String.COMPACT_STRINGS;
34 import static java.lang.String.LATIN1;
35 import static java.lang.String.UTF16;
36
37 /**
38 * The {@code Long} class wraps a value of the primitive type {@code
39 * long} in an object. An object of type {@code Long} contains a
40 * single field whose type is {@code long}.
41 *
42 * <p> In addition, this class provides several methods for converting
43 * a {@code long} to a {@code String} and a {@code String} to a {@code
44 * long}, as well as other constants and methods useful when dealing
45 * with a {@code long}.
46 *
47 * <p>Implementation note: The implementations of the "bit twiddling"
48 * methods (such as {@link #highestOneBit(long) highestOneBit} and
49 * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are
50 * based on material from Henry S. Warren, Jr.'s <i>Hacker's
51 * Delight</i>, (Addison Wesley, 2002).
52 *
53 * @author Lee Boynton
54 * @author Arthur van Hoff
55 * @author Josh Bloch
56 * @author Joseph D. Darcy
57 * @since 1.0
58 */
59 public final class Long extends Number implements Comparable<Long> {
60 /**
61 * A constant holding the minimum value a {@code long} can
62 * have, -2<sup>63</sup>.
63 */
64 @Native public static final long MIN_VALUE = 0x8000000000000000L;
65
66 /**
67 * A constant holding the maximum value a {@code long} can
68 * have, 2<sup>63</sup>-1.
69 */
70 @Native public static final long MAX_VALUE = 0x7fffffffffffffffL;
71
72 /**
73 * The {@code Class} instance representing the primitive type
74 * {@code long}.
75 *
76 * @since 1.1
77 */
78 @SuppressWarnings("unchecked")
79 public static final Class<Long> TYPE = (Class<Long>) Class.getPrimitiveClass("long");
80
81 /**
82 * Returns a string representation of the first argument in the
83 * radix specified by the second argument.
84 *
85 * <p>If the radix is smaller than {@code Character.MIN_RADIX}
86 * or larger than {@code Character.MAX_RADIX}, then the radix
87 * {@code 10} is used instead.
88 *
89 * <p>If the first argument is negative, the first element of the
90 * result is the ASCII minus sign {@code '-'}
91 * ({@code '\u005Cu002d'}). If the first argument is not
92 * negative, no sign character appears in the result.
93 *
94 * <p>The remaining characters of the result represent the magnitude
95 * of the first argument. If the magnitude is zero, it is
96 * represented by a single zero character {@code '0'}
97 * ({@code '\u005Cu0030'}); otherwise, the first character of
98 * the representation of the magnitude will not be the zero
99 * character. The following ASCII characters are used as digits:
100 *
101 * <blockquote>
102 * {@code 0123456789abcdefghijklmnopqrstuvwxyz}
103 * </blockquote>
104 *
105 * These are {@code '\u005Cu0030'} through
106 * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through
107 * {@code '\u005Cu007a'}. If {@code radix} is
108 * <var>N</var>, then the first <var>N</var> of these characters
109 * are used as radix-<var>N</var> digits in the order shown. Thus,
110 * the digits for hexadecimal (radix 16) are
111 * {@code 0123456789abcdef}. If uppercase letters are
112 * desired, the {@link java.lang.String#toUpperCase()} method may
113 * be called on the result:
114 *
115 * <blockquote>
116 * {@code Long.toString(n, 16).toUpperCase()}
117 * </blockquote>
118 *
119 * @param i a {@code long} to be converted to a string.
120 * @param radix the radix to use in the string representation.
121 * @return a string representation of the argument in the specified radix.
122 * @see java.lang.Character#MAX_RADIX
123 * @see java.lang.Character#MIN_RADIX
124 */
125 public static String toString(long i, int radix) {
126 if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
127 radix = 10;
128 if (radix == 10)
129 return toString(i);
130
131 if (COMPACT_STRINGS) {
132 byte[] buf = new byte[65];
133 int charPos = 64;
134 boolean negative = (i < 0);
135
136 if (!negative) {
137 i = -i;
138 }
139
140 while (i <= -radix) {
141 buf[charPos--] = (byte)Integer.digits[(int)(-(i % radix))];
142 i = i / radix;
143 }
144 buf[charPos] = (byte)Integer.digits[(int)(-i)];
145
146 if (negative) {
147 buf[--charPos] = '-';
148 }
149 return StringLatin1.newString(buf, charPos, (65 - charPos));
150 }
151 return toStringUTF16(i, radix);
152 }
153
154 private static String toStringUTF16(long i, int radix) {
155 byte[] buf = new byte[65 * 2];
156 int charPos = 64;
157 boolean negative = (i < 0);
158 if (!negative) {
159 i = -i;
160 }
161 while (i <= -radix) {
162 StringUTF16.putChar(buf, charPos--, Integer.digits[(int)(-(i % radix))]);
163 i = i / radix;
164 }
165 StringUTF16.putChar(buf, charPos, Integer.digits[(int)(-i)]);
166 if (negative) {
167 StringUTF16.putChar(buf, --charPos, '-');
168 }
169 return StringUTF16.newString(buf, charPos, (65 - charPos));
170 }
171
172 /**
173 * Returns a string representation of the first argument as an
174 * unsigned integer value in the radix specified by the second
175 * argument.
176 *
177 * <p>If the radix is smaller than {@code Character.MIN_RADIX}
178 * or larger than {@code Character.MAX_RADIX}, then the radix
179 * {@code 10} is used instead.
180 *
181 * <p>Note that since the first argument is treated as an unsigned
182 * value, no leading sign character is printed.
183 *
184 * <p>If the magnitude is zero, it is represented by a single zero
185 * character {@code '0'} ({@code '\u005Cu0030'}); otherwise,
186 * the first character of the representation of the magnitude will
187 * not be the zero character.
188 *
189 * <p>The behavior of radixes and the characters used as digits
190 * are the same as {@link #toString(long, int) toString}.
191 *
192 * @param i an integer to be converted to an unsigned string.
193 * @param radix the radix to use in the string representation.
194 * @return an unsigned string representation of the argument in the specified radix.
195 * @see #toString(long, int)
196 * @since 1.8
197 */
198 public static String toUnsignedString(long i, int radix) {
199 if (i >= 0)
200 return toString(i, radix);
201 else {
202 switch (radix) {
203 case 2:
204 return toBinaryString(i);
205
206 case 4:
207 return toUnsignedString0(i, 2);
208
209 case 8:
210 return toOctalString(i);
211
212 case 10:
213 /*
214 * We can get the effect of an unsigned division by 10
215 * on a long value by first shifting right, yielding a
216 * positive value, and then dividing by 5. This
217 * allows the last digit and preceding digits to be
218 * isolated more quickly than by an initial conversion
219 * to BigInteger.
220 */
221 long quot = (i >>> 1) / 5;
222 long rem = i - quot * 10;
223 return toString(quot) + rem;
224
225 case 16:
226 return toHexString(i);
227
228 case 32:
229 return toUnsignedString0(i, 5);
230
231 default:
232 return toUnsignedBigInteger(i).toString(radix);
233 }
234 }
235 }
236
237 /**
238 * Return a BigInteger equal to the unsigned value of the
239 * argument.
240 */
241 private static BigInteger toUnsignedBigInteger(long i) {
242 if (i >= 0L)
243 return BigInteger.valueOf(i);
244 else {
245 int upper = (int) (i >>> 32);
246 int lower = (int) i;
247
248 // return (upper << 32) + lower
249 return (BigInteger.valueOf(Integer.toUnsignedLong(upper))).shiftLeft(32).
250 add(BigInteger.valueOf(Integer.toUnsignedLong(lower)));
251 }
252 }
253
254 /**
255 * Returns a string representation of the {@code long}
256 * argument as an unsigned integer in base 16.
257 *
258 * <p>The unsigned {@code long} value is the argument plus
259 * 2<sup>64</sup> if the argument is negative; otherwise, it is
260 * equal to the argument. This value is converted to a string of
261 * ASCII digits in hexadecimal (base 16) with no extra
262 * leading {@code 0}s.
263 *
264 * <p>The value of the argument can be recovered from the returned
265 * string {@code s} by calling {@link
266 * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
267 * 16)}.
268 *
269 * <p>If the unsigned magnitude is zero, it is represented by a
270 * single zero character {@code '0'} ({@code '\u005Cu0030'});
271 * otherwise, the first character of the representation of the
272 * unsigned magnitude will not be the zero character. The
273 * following characters are used as hexadecimal digits:
274 *
275 * <blockquote>
276 * {@code 0123456789abcdef}
277 * </blockquote>
278 *
279 * These are the characters {@code '\u005Cu0030'} through
280 * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through
281 * {@code '\u005Cu0066'}. If uppercase letters are desired,
282 * the {@link java.lang.String#toUpperCase()} method may be called
283 * on the result:
284 *
285 * <blockquote>
286 * {@code Long.toHexString(n).toUpperCase()}
287 * </blockquote>
288 *
289 * @param i a {@code long} to be converted to a string.
290 * @return the string representation of the unsigned {@code long}
291 * value represented by the argument in hexadecimal
292 * (base 16).
293 * @see #parseUnsignedLong(String, int)
294 * @see #toUnsignedString(long, int)
295 * @since 1.0.2
296 */
297 public static String toHexString(long i) {
298 return toUnsignedString0(i, 4);
299 }
300
301 /**
302 * Returns a string representation of the {@code long}
303 * argument as an unsigned integer in base 8.
304 *
305 * <p>The unsigned {@code long} value is the argument plus
306 * 2<sup>64</sup> if the argument is negative; otherwise, it is
307 * equal to the argument. This value is converted to a string of
308 * ASCII digits in octal (base 8) with no extra leading
309 * {@code 0}s.
310 *
311 * <p>The value of the argument can be recovered from the returned
312 * string {@code s} by calling {@link
313 * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
314 * 8)}.
315 *
316 * <p>If the unsigned magnitude is zero, it is represented by a
317 * single zero character {@code '0'} ({@code '\u005Cu0030'});
318 * otherwise, the first character of the representation of the
319 * unsigned magnitude will not be the zero character. The
320 * following characters are used as octal digits:
321 *
322 * <blockquote>
323 * {@code 01234567}
324 * </blockquote>
325 *
326 * These are the characters {@code '\u005Cu0030'} through
327 * {@code '\u005Cu0037'}.
328 *
329 * @param i a {@code long} to be converted to a string.
330 * @return the string representation of the unsigned {@code long}
331 * value represented by the argument in octal (base 8).
332 * @see #parseUnsignedLong(String, int)
333 * @see #toUnsignedString(long, int)
334 * @since 1.0.2
335 */
336 public static String toOctalString(long i) {
337 return toUnsignedString0(i, 3);
338 }
339
340 /**
341 * Returns a string representation of the {@code long}
342 * argument as an unsigned integer in base 2.
343 *
344 * <p>The unsigned {@code long} value is the argument plus
345 * 2<sup>64</sup> if the argument is negative; otherwise, it is
346 * equal to the argument. This value is converted to a string of
347 * ASCII digits in binary (base 2) with no extra leading
348 * {@code 0}s.
349 *
350 * <p>The value of the argument can be recovered from the returned
351 * string {@code s} by calling {@link
352 * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
353 * 2)}.
354 *
355 * <p>If the unsigned magnitude is zero, it is represented by a
356 * single zero character {@code '0'} ({@code '\u005Cu0030'});
357 * otherwise, the first character of the representation of the
358 * unsigned magnitude will not be the zero character. The
359 * characters {@code '0'} ({@code '\u005Cu0030'}) and {@code
360 * '1'} ({@code '\u005Cu0031'}) are used as binary digits.
361 *
362 * @param i a {@code long} to be converted to a string.
363 * @return the string representation of the unsigned {@code long}
364 * value represented by the argument in binary (base 2).
365 * @see #parseUnsignedLong(String, int)
366 * @see #toUnsignedString(long, int)
367 * @since 1.0.2
368 */
369 public static String toBinaryString(long i) {
370 return toUnsignedString0(i, 1);
371 }
372
373 /**
374 * Format a long (treated as unsigned) into a String.
375 * @param val the value to format
376 * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
377 */
378 static String toUnsignedString0(long val, int shift) {
379 // assert shift > 0 && shift <=5 : "Illegal shift value";
380 int mag = Long.SIZE - Long.numberOfLeadingZeros(val);
381 int chars = Math.max(((mag + (shift - 1)) / shift), 1);
382 if (COMPACT_STRINGS) {
383 byte[] buf = new byte[chars];
384 formatUnsignedLong0(val, shift, buf, 0, chars);
385 return new String(buf, LATIN1);
386 } else {
387 byte[] buf = new byte[chars * 2];
388 formatUnsignedLong0UTF16(val, shift, buf, 0, chars);
389 return new String(buf, UTF16);
390 }
391 }
392
393 /**
394 * Format a long (treated as unsigned) into a character buffer. If
395 * {@code len} exceeds the formatted ASCII representation of {@code val},
396 * {@code buf} will be padded with leading zeroes.
397 *
398 * @param val the unsigned long to format
399 * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
400 * @param buf the character buffer to write to
401 * @param offset the offset in the destination buffer to start at
402 * @param len the number of characters to write
403 */
404 static void formatUnsignedLong(long val, int shift, char[] buf, int offset, int len) {
405 // assert shift > 0 && shift <=5 : "Illegal shift value";
406 // assert offset >= 0 && offset < buf.length : "illegal offset";
407 // assert len > 0 && (offset + len) <= buf.length : "illegal length";
408 int charPos = offset + len;
409 int radix = 1 << shift;
410 int mask = radix - 1;
411 do {
412 buf[--charPos] = Integer.digits[((int) val) & mask];
413 val >>>= shift;
414 } while (charPos > offset);
415 }
416
417 /** byte[]/LATIN1 version */
418 static void formatUnsignedLong0(long val, int shift, byte[] buf, int offset, int len) {
419 int charPos = offset + len;
420 int radix = 1 << shift;
421 int mask = radix - 1;
422 do {
423 buf[--charPos] = (byte)Integer.digits[((int) val) & mask];
424 val >>>= shift;
425 } while (charPos > offset);
426 }
427
428 /** byte[]/UTF16 version */
429 static void formatUnsignedLong0UTF16(long val, int shift, byte[] buf, int offset, int len) {
430 int charPos = offset + len;
431 int radix = 1 << shift;
432 int mask = radix - 1;
433 do {
434 StringUTF16.putChar(buf, --charPos, Integer.digits[((int) val) & mask]);
435 val >>>= shift;
436 } while (charPos > offset);
437 }
438
439 /**
440 * Returns a {@code String} object representing the specified
441 * {@code long}. The argument is converted to signed decimal
442 * representation and returned as a string, exactly as if the
443 * argument and the radix 10 were given as arguments to the {@link
444 * #toString(long, int)} method.
445 *
446 * @param i a {@code long} to be converted.
447 * @return a string representation of the argument in base 10.
448 */
449 public static String toString(long i) {
450 int size = stringSize(i);
451 if (COMPACT_STRINGS) {
452 byte[] buf = new byte[size];
453 getChars(i, size, buf);
454 return new String(buf, LATIN1);
455 } else {
456 byte[] buf = new byte[size * 2];
457 getCharsUTF16(i, size, buf);
458 return new String(buf, UTF16);
459 }
460 }
461
462 /**
463 * Returns a string representation of the argument as an unsigned
464 * decimal value.
465 *
466 * The argument is converted to unsigned decimal representation
467 * and returned as a string exactly as if the argument and radix
468 * 10 were given as arguments to the {@link #toUnsignedString(long,
469 * int)} method.
470 *
471 * @param i an integer to be converted to an unsigned string.
472 * @return an unsigned string representation of the argument.
473 * @see #toUnsignedString(long, int)
474 * @since 1.8
475 */
476 public static String toUnsignedString(long i) {
477 return toUnsignedString(i, 10);
478 }
479
480 /**
481 * Places characters representing the long i into the
482 * character array buf. The characters are placed into
483 * the buffer backwards starting with the least significant
484 * digit at the specified index (exclusive), and working
485 * backwards from there.
486 *
487 * @implNote This method converts positive inputs into negative
488 * values, to cover the Long.MIN_VALUE case. Converting otherwise
489 * (negative to positive) will expose -Long.MIN_VALUE that overflows
490 * long.
491 *
492 * @param i value to convert
493 * @param index next index, after the least significant digit
494 * @param buf target buffer, Latin1-encoded
495 * @return index of the most significant digit or minus sign, if present
496 */
497 static int getChars(long i, int index, byte[] buf) {
498 long q;
499 int r;
500 int charPos = index;
501
502 boolean negative = (i < 0);
503 if (!negative) {
504 i = -i;
505 }
506
507 // Get 2 digits/iteration using longs until quotient fits into an int
508 while (i <= Integer.MIN_VALUE) {
509 q = i / 100;
510 r = (int)((q * 100) - i);
511 i = q;
512 buf[--charPos] = Integer.DigitOnes[r];
513 buf[--charPos] = Integer.DigitTens[r];
514 }
515
516 // Get 2 digits/iteration using ints
517 int q2;
518 int i2 = (int)i;
519 while (i2 <= -100) {
520 q2 = i2 / 100;
521 r = (q2 * 100) - i2;
522 i2 = q2;
523 buf[--charPos] = Integer.DigitOnes[r];
524 buf[--charPos] = Integer.DigitTens[r];
525 }
526
527 // We know there are at most two digits left at this point.
528 q2 = i2 / 10;
529 r = (q2 * 10) - i2;
530 buf[--charPos] = (byte)('0' + r);
531
532 // Whatever left is the remaining digit.
533 if (q2 < 0) {
534 buf[--charPos] = (byte)('0' - q2);
535 }
536
537 if (negative) {
538 buf[--charPos] = (byte)'-';
539 }
540 return charPos;
541 }
542
543 /**
544 * This is a variant of {@link #getChars(long, int, byte[])}, but for
545 * UTF-16 coder.
546 *
547 * @param i value to convert
548 * @param index next index, after the least significant digit
549 * @param buf target buffer, UTF16-coded.
550 * @return index of the most significant digit or minus sign, if present
551 */
552 static int getCharsUTF16(long i, int index, byte[] buf) {
553 long q;
554 int r;
555 int charPos = index;
556
557 boolean negative = (i < 0);
558 if (!negative) {
559 i = -i;
560 }
561
562 // Get 2 digits/iteration using longs until quotient fits into an int
563 while (i <= Integer.MIN_VALUE) {
564 q = i / 100;
565 r = (int)((q * 100) - i);
566 i = q;
567 StringUTF16.putChar(buf, --charPos, Integer.DigitOnes[r]);
568 StringUTF16.putChar(buf, --charPos, Integer.DigitTens[r]);
569 }
570
571 // Get 2 digits/iteration using ints
572 int q2;
573 int i2 = (int)i;
574 while (i2 <= -100) {
575 q2 = i2 / 100;
576 r = (q2 * 100) - i2;
577 i2 = q2;
578 StringUTF16.putChar(buf, --charPos, Integer.DigitOnes[r]);
579 StringUTF16.putChar(buf, --charPos, Integer.DigitTens[r]);
580 }
581
582 // We know there are at most two digits left at this point.
583 q2 = i2 / 10;
584 r = (q2 * 10) - i2;
585 StringUTF16.putChar(buf, --charPos, '0' + r);
586
587 // Whatever left is the remaining digit.
588 if (q2 < 0) {
589 StringUTF16.putChar(buf, --charPos, '0' - q2);
590 }
591
592 if (negative) {
593 StringUTF16.putChar(buf, --charPos, '-');
594 }
595 return charPos;
596 }
597
598 /**
599 * Returns the string representation size for a given long value.
600 *
601 * @param x long value
602 * @return string size
603 *
604 * @implNote There are other ways to compute this: e.g. binary search,
605 * but values are biased heavily towards zero, and therefore linear search
606 * wins. The iteration results are also routinely inlined in the generated
607 * code after loop unrolling.
608 */
609 static int stringSize(long x) {
610 int d = 1;
611 if (x >= 0) {
612 d = 0;
613 x = -x;
614 }
615 long p = -10;
616 for (int i = 1; i < 19; i++) {
617 if (x > p)
618 return i + d;
619 p = 10 * p;
620 }
621 return 19 + d;
622 }
623
624 /**
625 * Parses the string argument as a signed {@code long} in the
626 * radix specified by the second argument. The characters in the
627 * string must all be digits of the specified radix (as determined
628 * by whether {@link java.lang.Character#digit(char, int)} returns
629 * a nonnegative value), except that the first character may be an
630 * ASCII minus sign {@code '-'} ({@code '\u005Cu002D'}) to
631 * indicate a negative value or an ASCII plus sign {@code '+'}
632 * ({@code '\u005Cu002B'}) to indicate a positive value. The
633 * resulting {@code long} value is returned.
634 *
635 * <p>Note that neither the character {@code L}
636 * ({@code '\u005Cu004C'}) nor {@code l}
637 * ({@code '\u005Cu006C'}) is permitted to appear at the end
638 * of the string as a type indicator, as would be permitted in
639 * Java programming language source code - except that either
640 * {@code L} or {@code l} may appear as a digit for a
641 * radix greater than or equal to 22.
642 *
643 * <p>An exception of type {@code NumberFormatException} is
644 * thrown if any of the following situations occurs:
645 * <ul>
646 *
647 * <li>The first argument is {@code null} or is a string of
648 * length zero.
649 *
650 * <li>The {@code radix} is either smaller than {@link
651 * java.lang.Character#MIN_RADIX} or larger than {@link
652 * java.lang.Character#MAX_RADIX}.
653 *
654 * <li>Any character of the string is not a digit of the specified
655 * radix, except that the first character may be a minus sign
656 * {@code '-'} ({@code '\u005Cu002d'}) or plus sign {@code
657 * '+'} ({@code '\u005Cu002B'}) provided that the string is
658 * longer than length 1.
659 *
660 * <li>The value represented by the string is not a value of type
661 * {@code long}.
662 * </ul>
663 *
664 * <p>Examples:
665 * <blockquote><pre>
666 * parseLong("0", 10) returns 0L
667 * parseLong("473", 10) returns 473L
668 * parseLong("+42", 10) returns 42L
669 * parseLong("-0", 10) returns 0L
670 * parseLong("-FF", 16) returns -255L
671 * parseLong("1100110", 2) returns 102L
672 * parseLong("99", 8) throws a NumberFormatException
673 * parseLong("Hazelnut", 10) throws a NumberFormatException
674 * parseLong("Hazelnut", 36) returns 1356099454469L
675 * </pre></blockquote>
676 *
677 * @param s the {@code String} containing the
678 * {@code long} representation to be parsed.
679 * @param radix the radix to be used while parsing {@code s}.
680 * @return the {@code long} represented by the string argument in
681 * the specified radix.
682 * @throws NumberFormatException if the string does not contain a
683 * parsable {@code long}.
684 */
685 public static long parseLong(String s, int radix)
686 throws NumberFormatException
687 {
688 if (s == null) {
689 throw new NumberFormatException("null");
690 }
691
692 if (radix < Character.MIN_RADIX) {
693 throw new NumberFormatException("radix " + radix +
694 " less than Character.MIN_RADIX");
695 }
696 if (radix > Character.MAX_RADIX) {
697 throw new NumberFormatException("radix " + radix +
698 " greater than Character.MAX_RADIX");
699 }
700
701 boolean negative = false;
702 int i = 0, len = s.length();
703 long limit = -Long.MAX_VALUE;
704
705 if (len > 0) {
706 char firstChar = s.charAt(0);
707 if (firstChar < '0') { // Possible leading "+" or "-"
708 if (firstChar == '-') {
709 negative = true;
710 limit = Long.MIN_VALUE;
711 } else if (firstChar != '+') {
712 throw NumberFormatException.forInputString(s);
713 }
714
715 if (len == 1) { // Cannot have lone "+" or "-"
716 throw NumberFormatException.forInputString(s);
717 }
718 i++;
719 }
720 long multmin = limit / radix;
721 long result = 0;
722 while (i < len) {
723 // Accumulating negatively avoids surprises near MAX_VALUE
724 int digit = Character.digit(s.charAt(i++),radix);
725 if (digit < 0 || result < multmin) {
726 throw NumberFormatException.forInputString(s);
727 }
728 result *= radix;
729 if (result < limit + digit) {
730 throw NumberFormatException.forInputString(s);
731 }
732 result -= digit;
733 }
734 return negative ? result : -result;
735 } else {
736 throw NumberFormatException.forInputString(s);
737 }
738 }
739
740 /**
741 * Parses the {@link CharSequence} argument as a signed {@code long} in
742 * the specified {@code radix}, beginning at the specified
743 * {@code beginIndex} and extending to {@code endIndex - 1}.
744 *
745 * <p>The method does not take steps to guard against the
746 * {@code CharSequence} being mutated while parsing.
747 *
748 * @param s the {@code CharSequence} containing the {@code long}
749 * representation to be parsed
750 * @param beginIndex the beginning index, inclusive.
751 * @param endIndex the ending index, exclusive.
752 * @param radix the radix to be used while parsing {@code s}.
753 * @return the signed {@code long} represented by the subsequence in
754 * the specified radix.
755 * @throws NullPointerException if {@code s} is null.
756 * @throws IndexOutOfBoundsException if {@code beginIndex} is
757 * negative, or if {@code beginIndex} is greater than
758 * {@code endIndex} or if {@code endIndex} is greater than
759 * {@code s.length()}.
760 * @throws NumberFormatException if the {@code CharSequence} does not
761 * contain a parsable {@code int} in the specified
762 * {@code radix}, or if {@code radix} is either smaller than
763 * {@link java.lang.Character#MIN_RADIX} or larger than
764 * {@link java.lang.Character#MAX_RADIX}.
765 * @since 9
766 */
767 public static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix)
768 throws NumberFormatException {
769 s = Objects.requireNonNull(s);
770
771 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
772 throw new IndexOutOfBoundsException();
773 }
774 if (radix < Character.MIN_RADIX) {
775 throw new NumberFormatException("radix " + radix +
776 " less than Character.MIN_RADIX");
777 }
778 if (radix > Character.MAX_RADIX) {
779 throw new NumberFormatException("radix " + radix +
780 " greater than Character.MAX_RADIX");
781 }
782
783 boolean negative = false;
784 int i = beginIndex;
785 long limit = -Long.MAX_VALUE;
786
787 if (i < endIndex) {
788 char firstChar = s.charAt(i);
789 if (firstChar < '0') { // Possible leading "+" or "-"
790 if (firstChar == '-') {
791 negative = true;
792 limit = Long.MIN_VALUE;
793 } else if (firstChar != '+') {
794 throw NumberFormatException.forCharSequence(s, beginIndex,
795 endIndex, i);
796 }
797 i++;
798 }
799 if (i >= endIndex) { // Cannot have lone "+", "-" or ""
800 throw NumberFormatException.forCharSequence(s, beginIndex,
801 endIndex, i);
802 }
803 long multmin = limit / radix;
804 long result = 0;
805 while (i < endIndex) {
806 // Accumulating negatively avoids surprises near MAX_VALUE
807 int digit = Character.digit(s.charAt(i), radix);
808 if (digit < 0 || result < multmin) {
809 throw NumberFormatException.forCharSequence(s, beginIndex,
810 endIndex, i);
811 }
812 result *= radix;
813 if (result < limit + digit) {
814 throw NumberFormatException.forCharSequence(s, beginIndex,
815 endIndex, i);
816 }
817 i++;
818 result -= digit;
819 }
820 return negative ? result : -result;
821 } else {
822 throw new NumberFormatException("");
823 }
824 }
825
826 /**
827 * Parses the string argument as a signed decimal {@code long}.
828 * The characters in the string must all be decimal digits, except
829 * that the first character may be an ASCII minus sign {@code '-'}
830 * ({@code \u005Cu002D'}) to indicate a negative value or an
831 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
832 * indicate a positive value. The resulting {@code long} value is
833 * returned, exactly as if the argument and the radix {@code 10}
834 * were given as arguments to the {@link
835 * #parseLong(java.lang.String, int)} method.
836 *
837 * <p>Note that neither the character {@code L}
838 * ({@code '\u005Cu004C'}) nor {@code l}
839 * ({@code '\u005Cu006C'}) is permitted to appear at the end
840 * of the string as a type indicator, as would be permitted in
841 * Java programming language source code.
842 *
843 * @param s a {@code String} containing the {@code long}
844 * representation to be parsed
845 * @return the {@code long} represented by the argument in
846 * decimal.
847 * @throws NumberFormatException if the string does not contain a
848 * parsable {@code long}.
849 */
850 public static long parseLong(String s) throws NumberFormatException {
851 return parseLong(s, 10);
852 }
853
854 /**
855 * Parses the string argument as an unsigned {@code long} in the
856 * radix specified by the second argument. An unsigned integer
857 * maps the values usually associated with negative numbers to
858 * positive numbers larger than {@code MAX_VALUE}.
859 *
860 * The characters in the string must all be digits of the
861 * specified radix (as determined by whether {@link
862 * java.lang.Character#digit(char, int)} returns a nonnegative
863 * value), except that the first character may be an ASCII plus
864 * sign {@code '+'} ({@code '\u005Cu002B'}). The resulting
865 * integer value is returned.
866 *
867 * <p>An exception of type {@code NumberFormatException} is
868 * thrown if any of the following situations occurs:
869 * <ul>
870 * <li>The first argument is {@code null} or is a string of
871 * length zero.
872 *
873 * <li>The radix is either smaller than
874 * {@link java.lang.Character#MIN_RADIX} or
875 * larger than {@link java.lang.Character#MAX_RADIX}.
876 *
877 * <li>Any character of the string is not a digit of the specified
878 * radix, except that the first character may be a plus sign
879 * {@code '+'} ({@code '\u005Cu002B'}) provided that the
880 * string is longer than length 1.
881 *
882 * <li>The value represented by the string is larger than the
883 * largest unsigned {@code long}, 2<sup>64</sup>-1.
884 *
885 * </ul>
886 *
887 *
888 * @param s the {@code String} containing the unsigned integer
889 * representation to be parsed
890 * @param radix the radix to be used while parsing {@code s}.
891 * @return the unsigned {@code long} represented by the string
892 * argument in the specified radix.
893 * @throws NumberFormatException if the {@code String}
894 * does not contain a parsable {@code long}.
895 * @since 1.8
896 */
897 public static long parseUnsignedLong(String s, int radix)
898 throws NumberFormatException {
899 if (s == null) {
900 throw new NumberFormatException("null");
901 }
902
903 int len = s.length();
904 if (len > 0) {
905 char firstChar = s.charAt(0);
906 if (firstChar == '-') {
907 throw new
908 NumberFormatException(String.format("Illegal leading minus sign " +
909 "on unsigned string %s.", s));
910 } else {
911 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
912 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
913 return parseLong(s, radix);
914 }
915
916 // No need for range checks on len due to testing above.
917 long first = parseLong(s, 0, len - 1, radix);
918 int second = Character.digit(s.charAt(len - 1), radix);
919 if (second < 0) {
920 throw new NumberFormatException("Bad digit at end of " + s);
921 }
922 long result = first * radix + second;
923
924 /*
925 * Test leftmost bits of multiprecision extension of first*radix
926 * for overflow. The number of bits needed is defined by
927 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
928 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
929 * overflow is tested by splitting guard in the ranges
930 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
931 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
932 * on a value which does not include a prime factor in the legal
933 * radix range.
934 */
935 int guard = radix * (int) (first >>> 57);
936 if (guard >= 128 ||
937 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
938 /*
939 * For purposes of exposition, the programmatic statements
940 * below should be taken to be multi-precision, i.e., not
941 * subject to overflow.
942 *
943 * A) Condition guard >= 128:
944 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
945 * hence always overflow.
946 *
947 * B) Condition guard < 92:
948 * Define left7 = first >>> 57.
949 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
950 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
951 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
952 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
953 * never overflow.
954 *
955 * C) Condition 92 <= guard < 128:
956 * first*radix + second >= radix*left7*2^57 + second
957 * so that first*radix + second >= 92*2^57 + 0 > 2^63
958 *
959 * D) Condition guard < 128:
960 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
961 * so
962 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
963 * thus
964 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
965 * whence
966 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
967 *
968 * E) Conditions C, D, and result >= 0:
969 * C and D combined imply the mathematical result
970 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
971 * bound is therefore negative as a signed long, but the
972 * upper bound is too small to overflow again after the
973 * signed long overflows to positive above 2^64 - 1. Hence
974 * result >= 0 implies overflow given C and D.
975 */
976 throw new NumberFormatException(String.format("String value %s exceeds " +
977 "range of unsigned long.", s));
978 }
979 return result;
980 }
981 } else {
982 throw NumberFormatException.forInputString(s);
983 }
984 }
985
986 /**
987 * Parses the {@link CharSequence} argument as an unsigned {@code long} in
988 * the specified {@code radix}, beginning at the specified
989 * {@code beginIndex} and extending to {@code endIndex - 1}.
990 *
991 * <p>The method does not take steps to guard against the
992 * {@code CharSequence} being mutated while parsing.
993 *
994 * @param s the {@code CharSequence} containing the unsigned
995 * {@code long} representation to be parsed
996 * @param beginIndex the beginning index, inclusive.
997 * @param endIndex the ending index, exclusive.
998 * @param radix the radix to be used while parsing {@code s}.
999 * @return the unsigned {@code long} represented by the subsequence in
1000 * the specified radix.
1001 * @throws NullPointerException if {@code s} is null.
1002 * @throws IndexOutOfBoundsException if {@code beginIndex} is
1003 * negative, or if {@code beginIndex} is greater than
1004 * {@code endIndex} or if {@code endIndex} is greater than
1005 * {@code s.length()}.
1006 * @throws NumberFormatException if the {@code CharSequence} does not
1007 * contain a parsable unsigned {@code long} in the specified
1008 * {@code radix}, or if {@code radix} is either smaller than
1009 * {@link java.lang.Character#MIN_RADIX} or larger than
1010 * {@link java.lang.Character#MAX_RADIX}.
1011 * @since 9
1012 */
1013 public static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix)
1014 throws NumberFormatException {
1015 s = Objects.requireNonNull(s);
1016
1017 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
1018 throw new IndexOutOfBoundsException();
1019 }
1020 int start = beginIndex, len = endIndex - beginIndex;
1021
1022 if (len > 0) {
1023 char firstChar = s.charAt(start);
1024 if (firstChar == '-') {
1025 throw new NumberFormatException(String.format("Illegal leading minus sign " +
1026 "on unsigned string %s.", s.subSequence(start, start + len)));
1027 } else {
1028 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
1029 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
1030 return parseLong(s, start, start + len, radix);
1031 }
1032
1033 // No need for range checks on end due to testing above.
1034 long first = parseLong(s, start, start + len - 1, radix);
1035 int second = Character.digit(s.charAt(start + len - 1), radix);
1036 if (second < 0) {
1037 throw new NumberFormatException("Bad digit at end of " +
1038 s.subSequence(start, start + len));
1039 }
1040 long result = first * radix + second;
1041
1042 /*
1043 * Test leftmost bits of multiprecision extension of first*radix
1044 * for overflow. The number of bits needed is defined by
1045 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
1046 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
1047 * overflow is tested by splitting guard in the ranges
1048 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
1049 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
1050 * on a value which does not include a prime factor in the legal
1051 * radix range.
1052 */
1053 int guard = radix * (int) (first >>> 57);
1054 if (guard >= 128 ||
1055 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
1056 /*
1057 * For purposes of exposition, the programmatic statements
1058 * below should be taken to be multi-precision, i.e., not
1059 * subject to overflow.
1060 *
1061 * A) Condition guard >= 128:
1062 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
1063 * hence always overflow.
1064 *
1065 * B) Condition guard < 92:
1066 * Define left7 = first >>> 57.
1067 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
1068 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
1069 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
1070 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
1071 * never overflow.
1072 *
1073 * C) Condition 92 <= guard < 128:
1074 * first*radix + second >= radix*left7*2^57 + second
1075 * so that first*radix + second >= 92*2^57 + 0 > 2^63
1076 *
1077 * D) Condition guard < 128:
1078 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
1079 * so
1080 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
1081 * thus
1082 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
1083 * whence
1084 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
1085 *
1086 * E) Conditions C, D, and result >= 0:
1087 * C and D combined imply the mathematical result
1088 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
1089 * bound is therefore negative as a signed long, but the
1090 * upper bound is too small to overflow again after the
1091 * signed long overflows to positive above 2^64 - 1. Hence
1092 * result >= 0 implies overflow given C and D.
1093 */
1094 throw new NumberFormatException(String.format("String value %s exceeds " +
1095 "range of unsigned long.", s.subSequence(start, start + len)));
1096 }
1097 return result;
1098 }
1099 } else {
1100 throw NumberFormatException.forInputString("");
1101 }
1102 }
1103
1104 /**
1105 * Parses the string argument as an unsigned decimal {@code long}. The
1106 * characters in the string must all be decimal digits, except
1107 * that the first character may be an ASCII plus sign {@code
1108 * '+'} ({@code '\u005Cu002B'}). The resulting integer value
1109 * is returned, exactly as if the argument and the radix 10 were
1110 * given as arguments to the {@link
1111 * #parseUnsignedLong(java.lang.String, int)} method.
1112 *
1113 * @param s a {@code String} containing the unsigned {@code long}
1114 * representation to be parsed
1115 * @return the unsigned {@code long} value represented by the decimal string argument
1116 * @throws NumberFormatException if the string does not contain a
1117 * parsable unsigned integer.
1118 * @since 1.8
1119 */
1120 public static long parseUnsignedLong(String s) throws NumberFormatException {
1121 return parseUnsignedLong(s, 10);
1122 }
1123
1124 /**
1125 * Returns a {@code Long} object holding the value
1126 * extracted from the specified {@code String} when parsed
1127 * with the radix given by the second argument. The first
1128 * argument is interpreted as representing a signed
1129 * {@code long} in the radix specified by the second
1130 * argument, exactly as if the arguments were given to the {@link
1131 * #parseLong(java.lang.String, int)} method. The result is a
1132 * {@code Long} object that represents the {@code long}
1133 * value specified by the string.
1134 *
1135 * <p>In other words, this method returns a {@code Long} object equal
1136 * to the value of:
1137 *
1138 * <blockquote>
1139 * {@code new Long(Long.parseLong(s, radix))}
1140 * </blockquote>
1141 *
1142 * @param s the string to be parsed
1143 * @param radix the radix to be used in interpreting {@code s}
1144 * @return a {@code Long} object holding the value
1145 * represented by the string argument in the specified
1146 * radix.
1147 * @throws NumberFormatException If the {@code String} does not
1148 * contain a parsable {@code long}.
1149 */
1150 public static Long valueOf(String s, int radix) throws NumberFormatException {
1151 return Long.valueOf(parseLong(s, radix));
1152 }
1153
1154 /**
1155 * Returns a {@code Long} object holding the value
1156 * of the specified {@code String}. The argument is
1157 * interpreted as representing a signed decimal {@code long},
1158 * exactly as if the argument were given to the {@link
1159 * #parseLong(java.lang.String)} method. The result is a
1160 * {@code Long} object that represents the integer value
1161 * specified by the string.
1162 *
1163 * <p>In other words, this method returns a {@code Long} object
1164 * equal to the value of:
1165 *
1166 * <blockquote>
1167 * {@code new Long(Long.parseLong(s))}
1168 * </blockquote>
1169 *
1170 * @param s the string to be parsed.
1171 * @return a {@code Long} object holding the value
1172 * represented by the string argument.
1173 * @throws NumberFormatException If the string cannot be parsed
1174 * as a {@code long}.
1175 */
1176 public static Long valueOf(String s) throws NumberFormatException
1177 {
1178 return Long.valueOf(parseLong(s, 10));
1179 }
1180
1181 private static class LongCache {
1182 private LongCache(){}
1183
1184 static final Long cache[] = new Long[-(-128) + 127 + 1];
1185
1186 static {
1187 for(int i = 0; i < cache.length; i++)
1188 cache[i] = new Long(i - 128);
1189 }
1190 }
1191
1192 /**
1193 * Returns a {@code Long} instance representing the specified
1194 * {@code long} value.
1195 * If a new {@code Long} instance is not required, this method
1196 * should generally be used in preference to the constructor
1197 * {@link #Long(long)}, as this method is likely to yield
1198 * significantly better space and time performance by caching
1199 * frequently requested values.
1200 *
1201 * Note that unlike the {@linkplain Integer#valueOf(int)
1202 * corresponding method} in the {@code Integer} class, this method
1203 * is <em>not</em> required to cache values within a particular
1204 * range.
1205 *
1206 * @param l a long value.
1207 * @return a {@code Long} instance representing {@code l}.
1208 * @since 1.5
1209 */
1210 @HotSpotIntrinsicCandidate
1211 public static Long valueOf(long l) {
1212 final int offset = 128;
1213 if (l >= -128 && l <= 127) { // will cache
1214 return LongCache.cache[(int)l + offset];
1215 }
1216 return new Long(l);
1217 }
1218
1219 /**
1220 * Decodes a {@code String} into a {@code Long}.
1221 * Accepts decimal, hexadecimal, and octal numbers given by the
1222 * following grammar:
1223 *
1224 * <blockquote>
1225 * <dl>
1226 * <dt><i>DecodableString:</i>
1227 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
1228 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
1229 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
1230 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
1231 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
1232 *
1233 * <dt><i>Sign:</i>
1234 * <dd>{@code -}
1235 * <dd>{@code +}
1236 * </dl>
1237 * </blockquote>
1238 *
1239 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
1240 * are as defined in section 3.10.1 of
1241 * <cite>The Java™ Language Specification</cite>,
1242 * except that underscores are not accepted between digits.
1243 *
1244 * <p>The sequence of characters following an optional
1245 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
1246 * "{@code #}", or leading zero) is parsed as by the {@code
1247 * Long.parseLong} method with the indicated radix (10, 16, or 8).
1248 * This sequence of characters must represent a positive value or
1249 * a {@link NumberFormatException} will be thrown. The result is
1250 * negated if first character of the specified {@code String} is
1251 * the minus sign. No whitespace characters are permitted in the
1252 * {@code String}.
1253 *
1254 * @param nm the {@code String} to decode.
1255 * @return a {@code Long} object holding the {@code long}
1256 * value represented by {@code nm}
1257 * @throws NumberFormatException if the {@code String} does not
1258 * contain a parsable {@code long}.
1259 * @see java.lang.Long#parseLong(String, int)
1260 * @since 1.2
1261 */
1262 public static Long decode(String nm) throws NumberFormatException {
1263 int radix = 10;
1264 int index = 0;
1265 boolean negative = false;
1266 Long result;
1267
1268 if (nm.length() == 0)
1269 throw new NumberFormatException("Zero length string");
1270 char firstChar = nm.charAt(0);
1271 // Handle sign, if present
1272 if (firstChar == '-') {
1273 negative = true;
1274 index++;
1275 } else if (firstChar == '+')
1276 index++;
1277
1278 // Handle radix specifier, if present
1279 if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
1280 index += 2;
1281 radix = 16;
1282 }
1283 else if (nm.startsWith("#", index)) {
1284 index ++;
1285 radix = 16;
1286 }
1287 else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
1288 index ++;
1289 radix = 8;
1290 }
1291
1292 if (nm.startsWith("-", index) || nm.startsWith("+", index))
1293 throw new NumberFormatException("Sign character in wrong position");
1294
1295 try {
1296 result = Long.valueOf(nm.substring(index), radix);
1297 result = negative ? Long.valueOf(-result.longValue()) : result;
1298 } catch (NumberFormatException e) {
1299 // If number is Long.MIN_VALUE, we'll end up here. The next line
1300 // handles this case, and causes any genuine format error to be
1301 // rethrown.
1302 String constant = negative ? ("-" + nm.substring(index))
1303 : nm.substring(index);
1304 result = Long.valueOf(constant, radix);
1305 }
1306 return result;
1307 }
1308
1309 /**
1310 * The value of the {@code Long}.
1311 *
1312 * @serial
1313 */
1314 private final long value;
1315
1316 /**
1317 * Constructs a newly allocated {@code Long} object that
1318 * represents the specified {@code long} argument.
1319 *
1320 * @param value the value to be represented by the
1321 * {@code Long} object.
1322 */
1323 public Long(long value) {
1324 this.value = value;
1325 }
1326
1327 /**
1328 * Constructs a newly allocated {@code Long} object that
1329 * represents the {@code long} value indicated by the
1330 * {@code String} parameter. The string is converted to a
1331 * {@code long} value in exactly the manner used by the
1332 * {@code parseLong} method for radix 10.
1333 *
1334 * @param s the {@code String} to be converted to a
1335 * {@code Long}.
1336 * @throws NumberFormatException if the {@code String} does not
1337 * contain a parsable {@code long}.
1338 * @see java.lang.Long#parseLong(java.lang.String, int)
1339 */
1340 public Long(String s) throws NumberFormatException {
1341 this.value = parseLong(s, 10);
1342 }
1343
1344 /**
1345 * Returns the value of this {@code Long} as a {@code byte} after
1346 * a narrowing primitive conversion.
1347 * @jls 5.1.3 Narrowing Primitive Conversions
1348 */
1349 public byte byteValue() {
1350 return (byte)value;
1351 }
1352
1353 /**
1354 * Returns the value of this {@code Long} as a {@code short} after
1355 * a narrowing primitive conversion.
1356 * @jls 5.1.3 Narrowing Primitive Conversions
1357 */
1358 public short shortValue() {
1359 return (short)value;
1360 }
1361
1362 /**
1363 * Returns the value of this {@code Long} as an {@code int} after
1364 * a narrowing primitive conversion.
1365 * @jls 5.1.3 Narrowing Primitive Conversions
1366 */
1367 public int intValue() {
1368 return (int)value;
1369 }
1370
1371 /**
1372 * Returns the value of this {@code Long} as a
1373 * {@code long} value.
1374 */
1375 @HotSpotIntrinsicCandidate
1376 public long longValue() {
1377 return value;
1378 }
1379
1380 /**
1381 * Returns the value of this {@code Long} as a {@code float} after
1382 * a widening primitive conversion.
1383 * @jls 5.1.2 Widening Primitive Conversions
1384 */
1385 public float floatValue() {
1386 return (float)value;
1387 }
1388
1389 /**
1390 * Returns the value of this {@code Long} as a {@code double}
1391 * after a widening primitive conversion.
1392 * @jls 5.1.2 Widening Primitive Conversions
1393 */
1394 public double doubleValue() {
1395 return (double)value;
1396 }
1397
1398 /**
1399 * Returns a {@code String} object representing this
1400 * {@code Long}'s value. The value is converted to signed
1401 * decimal representation and returned as a string, exactly as if
1402 * the {@code long} value were given as an argument to the
1403 * {@link java.lang.Long#toString(long)} method.
1404 *
1405 * @return a string representation of the value of this object in
1406 * base 10.
1407 */
1408 public String toString() {
1409 return toString(value);
1410 }
1411
1412 /**
1413 * Returns a hash code for this {@code Long}. The result is
1414 * the exclusive OR of the two halves of the primitive
1415 * {@code long} value held by this {@code Long}
1416 * object. That is, the hashcode is the value of the expression:
1417 *
1418 * <blockquote>
1419 * {@code (int)(this.longValue()^(this.longValue()>>>32))}
1420 * </blockquote>
1421 *
1422 * @return a hash code value for this object.
1423 */
1424 @Override
1425 public int hashCode() {
1426 return Long.hashCode(value);
1427 }
1428
1429 /**
1430 * Returns a hash code for a {@code long} value; compatible with
1431 * {@code Long.hashCode()}.
1432 *
1433 * @param value the value to hash
1434 * @return a hash code value for a {@code long} value.
1435 * @since 1.8
1436 */
1437 public static int hashCode(long value) {
1438 return (int)(value ^ (value >>> 32));
1439 }
1440
1441 /**
1442 * Compares this object to the specified object. The result is
1443 * {@code true} if and only if the argument is not
1444 * {@code null} and is a {@code Long} object that
1445 * contains the same {@code long} value as this object.
1446 *
1447 * @param obj the object to compare with.
1448 * @return {@code true} if the objects are the same;
1449 * {@code false} otherwise.
1450 */
1451 public boolean equals(Object obj) {
1452 if (obj instanceof Long) {
1453 return value == ((Long)obj).longValue();
1454 }
1455 return false;
1456 }
1457
1458 /**
1459 * Determines the {@code long} value of the system property
1460 * with the specified name.
1461 *
1462 * <p>The first argument is treated as the name of a system
1463 * property. System properties are accessible through the {@link
1464 * java.lang.System#getProperty(java.lang.String)} method. The
1465 * string value of this property is then interpreted as a {@code
1466 * long} value using the grammar supported by {@link Long#decode decode}
1467 * and a {@code Long} object representing this value is returned.
1468 *
1469 * <p>If there is no property with the specified name, if the
1470 * specified name is empty or {@code null}, or if the property
1471 * does not have the correct numeric format, then {@code null} is
1472 * returned.
1473 *
1474 * <p>In other words, this method returns a {@code Long} object
1475 * equal to the value of:
1476 *
1477 * <blockquote>
1478 * {@code getLong(nm, null)}
1479 * </blockquote>
1480 *
1481 * @param nm property name.
1482 * @return the {@code Long} value of the property.
1483 * @throws SecurityException for the same reasons as
1484 * {@link System#getProperty(String) System.getProperty}
1485 * @see java.lang.System#getProperty(java.lang.String)
1486 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1487 */
1488 public static Long getLong(String nm) {
1489 return getLong(nm, null);
1490 }
1491
1492 /**
1493 * Determines the {@code long} value of the system property
1494 * with the specified name.
1495 *
1496 * <p>The first argument is treated as the name of a system
1497 * property. System properties are accessible through the {@link
1498 * java.lang.System#getProperty(java.lang.String)} method. The
1499 * string value of this property is then interpreted as a {@code
1500 * long} value using the grammar supported by {@link Long#decode decode}
1501 * and a {@code Long} object representing this value is returned.
1502 *
1503 * <p>The second argument is the default value. A {@code Long} object
1504 * that represents the value of the second argument is returned if there
1505 * is no property of the specified name, if the property does not have
1506 * the correct numeric format, or if the specified name is empty or null.
1507 *
1508 * <p>In other words, this method returns a {@code Long} object equal
1509 * to the value of:
1510 *
1511 * <blockquote>
1512 * {@code getLong(nm, new Long(val))}
1513 * </blockquote>
1514 *
1515 * but in practice it may be implemented in a manner such as:
1516 *
1517 * <blockquote><pre>
1518 * Long result = getLong(nm, null);
1519 * return (result == null) ? new Long(val) : result;
1520 * </pre></blockquote>
1521 *
1522 * to avoid the unnecessary allocation of a {@code Long} object when
1523 * the default value is not needed.
1524 *
1525 * @param nm property name.
1526 * @param val default value.
1527 * @return the {@code Long} value of the property.
1528 * @throws SecurityException for the same reasons as
1529 * {@link System#getProperty(String) System.getProperty}
1530 * @see java.lang.System#getProperty(java.lang.String)
1531 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1532 */
1533 public static Long getLong(String nm, long val) {
1534 Long result = Long.getLong(nm, null);
1535 return (result == null) ? Long.valueOf(val) : result;
1536 }
1537
1538 /**
1539 * Returns the {@code long} value of the system property with
1540 * the specified name. The first argument is treated as the name
1541 * of a system property. System properties are accessible through
1542 * the {@link java.lang.System#getProperty(java.lang.String)}
1543 * method. The string value of this property is then interpreted
1544 * as a {@code long} value, as per the
1545 * {@link Long#decode decode} method, and a {@code Long} object
1546 * representing this value is returned; in summary:
1547 *
1548 * <ul>
1549 * <li>If the property value begins with the two ASCII characters
1550 * {@code 0x} or the ASCII character {@code #}, not followed by
1551 * a minus sign, then the rest of it is parsed as a hexadecimal integer
1552 * exactly as for the method {@link #valueOf(java.lang.String, int)}
1553 * with radix 16.
1554 * <li>If the property value begins with the ASCII character
1555 * {@code 0} followed by another character, it is parsed as
1556 * an octal integer exactly as by the method {@link
1557 * #valueOf(java.lang.String, int)} with radix 8.
1558 * <li>Otherwise the property value is parsed as a decimal
1559 * integer exactly as by the method
1560 * {@link #valueOf(java.lang.String, int)} with radix 10.
1561 * </ul>
1562 *
1563 * <p>Note that, in every case, neither {@code L}
1564 * ({@code '\u005Cu004C'}) nor {@code l}
1565 * ({@code '\u005Cu006C'}) is permitted to appear at the end
1566 * of the property value as a type indicator, as would be
1567 * permitted in Java programming language source code.
1568 *
1569 * <p>The second argument is the default value. The default value is
1570 * returned if there is no property of the specified name, if the
1571 * property does not have the correct numeric format, or if the
1572 * specified name is empty or {@code null}.
1573 *
1574 * @param nm property name.
1575 * @param val default value.
1576 * @return the {@code Long} value of the property.
1577 * @throws SecurityException for the same reasons as
1578 * {@link System#getProperty(String) System.getProperty}
1579 * @see System#getProperty(java.lang.String)
1580 * @see System#getProperty(java.lang.String, java.lang.String)
1581 */
1582 public static Long getLong(String nm, Long val) {
1583 String v = null;
1584 try {
1585 v = System.getProperty(nm);
1586 } catch (IllegalArgumentException | NullPointerException e) {
1587 }
1588 if (v != null) {
1589 try {
1590 return Long.decode(v);
1591 } catch (NumberFormatException e) {
1592 }
1593 }
1594 return val;
1595 }
1596
1597 /**
1598 * Compares two {@code Long} objects numerically.
1599 *
1600 * @param anotherLong the {@code Long} to be compared.
1601 * @return the value {@code 0} if this {@code Long} is
1602 * equal to the argument {@code Long}; a value less than
1603 * {@code 0} if this {@code Long} is numerically less
1604 * than the argument {@code Long}; and a value greater
1605 * than {@code 0} if this {@code Long} is numerically
1606 * greater than the argument {@code Long} (signed
1607 * comparison).
1608 * @since 1.2
1609 */
1610 public int compareTo(Long anotherLong) {
1611 return compare(this.value, anotherLong.value);
1612 }
1613
1614 /**
1615 * Compares two {@code long} values numerically.
1616 * The value returned is identical to what would be returned by:
1617 * <pre>
1618 * Long.valueOf(x).compareTo(Long.valueOf(y))
1619 * </pre>
1620 *
1621 * @param x the first {@code long} to compare
1622 * @param y the second {@code long} to compare
1623 * @return the value {@code 0} if {@code x == y};
1624 * a value less than {@code 0} if {@code x < y}; and
1625 * a value greater than {@code 0} if {@code x > y}
1626 * @since 1.7
1627 */
1628 public static int compare(long x, long y) {
1629 return (x < y) ? -1 : ((x == y) ? 0 : 1);
1630 }
1631
1632 /**
1633 * Compares two {@code long} values numerically treating the values
1634 * as unsigned.
1635 *
1636 * @param x the first {@code long} to compare
1637 * @param y the second {@code long} to compare
1638 * @return the value {@code 0} if {@code x == y}; a value less
1639 * than {@code 0} if {@code x < y} as unsigned values; and
1640 * a value greater than {@code 0} if {@code x > y} as
1641 * unsigned values
1642 * @since 1.8
1643 */
1644 public static int compareUnsigned(long x, long y) {
1645 return compare(x + MIN_VALUE, y + MIN_VALUE);
1646 }
1647
1648
1649 /**
1650 * Returns the unsigned quotient of dividing the first argument by
1651 * the second where each argument and the result is interpreted as
1652 * an unsigned value.
1653 *
1654 * <p>Note that in two's complement arithmetic, the three other
1655 * basic arithmetic operations of add, subtract, and multiply are
1656 * bit-wise identical if the two operands are regarded as both
1657 * being signed or both being unsigned. Therefore separate {@code
1658 * addUnsigned}, etc. methods are not provided.
1659 *
1660 * @param dividend the value to be divided
1661 * @param divisor the value doing the dividing
1662 * @return the unsigned quotient of the first argument divided by
1663 * the second argument
1664 * @see #remainderUnsigned
1665 * @since 1.8
1666 */
1667 public static long divideUnsigned(long dividend, long divisor) {
1668 if (divisor < 0L) { // signed comparison
1669 // Answer must be 0 or 1 depending on relative magnitude
1670 // of dividend and divisor.
1671 return (compareUnsigned(dividend, divisor)) < 0 ? 0L :1L;
1672 }
1673
1674 if (dividend > 0) // Both inputs non-negative
1675 return dividend/divisor;
1676 else {
1677 /*
1678 * For simple code, leveraging BigInteger. Longer and faster
1679 * code written directly in terms of operations on longs is
1680 * possible; see "Hacker's Delight" for divide and remainder
1681 * algorithms.
1682 */
1683 return toUnsignedBigInteger(dividend).
1684 divide(toUnsignedBigInteger(divisor)).longValue();
1685 }
1686 }
1687
1688 /**
1689 * Returns the unsigned remainder from dividing the first argument
1690 * by the second where each argument and the result is interpreted
1691 * as an unsigned value.
1692 *
1693 * @param dividend the value to be divided
1694 * @param divisor the value doing the dividing
1695 * @return the unsigned remainder of the first argument divided by
1696 * the second argument
1697 * @see #divideUnsigned
1698 * @since 1.8
1699 */
1700 public static long remainderUnsigned(long dividend, long divisor) {
1701 if (dividend > 0 && divisor > 0) { // signed comparisons
1702 return dividend % divisor;
1703 } else {
1704 if (compareUnsigned(dividend, divisor) < 0) // Avoid explicit check for 0 divisor
1705 return dividend;
1706 else
1707 return toUnsignedBigInteger(dividend).
1708 remainder(toUnsignedBigInteger(divisor)).longValue();
1709 }
1710 }
1711
1712 // Bit Twiddling
1713
1714 /**
1715 * The number of bits used to represent a {@code long} value in two's
1716 * complement binary form.
1717 *
1718 * @since 1.5
1719 */
1720 @Native public static final int SIZE = 64;
1721
1722 /**
1723 * The number of bytes used to represent a {@code long} value in two's
1724 * complement binary form.
1725 *
1726 * @since 1.8
1727 */
1728 public static final int BYTES = SIZE / Byte.SIZE;
1729
1730 /**
1731 * Returns a {@code long} value with at most a single one-bit, in the
1732 * position of the highest-order ("leftmost") one-bit in the specified
1733 * {@code long} value. Returns zero if the specified value has no
1734 * one-bits in its two's complement binary representation, that is, if it
1735 * is equal to zero.
1736 *
1737 * @param i the value whose highest one bit is to be computed
1738 * @return a {@code long} value with a single one-bit, in the position
1739 * of the highest-order one-bit in the specified value, or zero if
1740 * the specified value is itself equal to zero.
1741 * @since 1.5
1742 */
1743 public static long highestOneBit(long i) {
1744 // HD, Figure 3-1
1745 i |= (i >> 1);
1746 i |= (i >> 2);
1747 i |= (i >> 4);
1748 i |= (i >> 8);
1749 i |= (i >> 16);
1750 i |= (i >> 32);
1751 return i - (i >>> 1);
1752 }
1753
1754 /**
1755 * Returns a {@code long} value with at most a single one-bit, in the
1756 * position of the lowest-order ("rightmost") one-bit in the specified
1757 * {@code long} value. Returns zero if the specified value has no
1758 * one-bits in its two's complement binary representation, that is, if it
1759 * is equal to zero.
1760 *
1761 * @param i the value whose lowest one bit is to be computed
1762 * @return a {@code long} value with a single one-bit, in the position
1763 * of the lowest-order one-bit in the specified value, or zero if
1764 * the specified value is itself equal to zero.
1765 * @since 1.5
1766 */
1767 public static long lowestOneBit(long i) {
1768 // HD, Section 2-1
1769 return i & -i;
1770 }
1771
1772 /**
1773 * Returns the number of zero bits preceding the highest-order
1774 * ("leftmost") one-bit in the two's complement binary representation
1775 * of the specified {@code long} value. Returns 64 if the
1776 * specified value has no one-bits in its two's complement representation,
1777 * in other words if it is equal to zero.
1778 *
1779 * <p>Note that this method is closely related to the logarithm base 2.
1780 * For all positive {@code long} values x:
1781 * <ul>
1782 * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}
1783 * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}
1784 * </ul>
1785 *
1786 * @param i the value whose number of leading zeros is to be computed
1787 * @return the number of zero bits preceding the highest-order
1788 * ("leftmost") one-bit in the two's complement binary representation
1789 * of the specified {@code long} value, or 64 if the value
1790 * is equal to zero.
1791 * @since 1.5
1792 */
1793 @HotSpotIntrinsicCandidate
1794 public static int numberOfLeadingZeros(long i) {
1795 // HD, Figure 5-6
1796 if (i == 0)
1797 return 64;
1798 int n = 1;
1799 int x = (int)(i >>> 32);
1800 if (x == 0) { n += 32; x = (int)i; }
1801 if (x >>> 16 == 0) { n += 16; x <<= 16; }
1802 if (x >>> 24 == 0) { n += 8; x <<= 8; }
1803 if (x >>> 28 == 0) { n += 4; x <<= 4; }
1804 if (x >>> 30 == 0) { n += 2; x <<= 2; }
1805 n -= x >>> 31;
1806 return n;
1807 }
1808
1809 /**
1810 * Returns the number of zero bits following the lowest-order ("rightmost")
1811 * one-bit in the two's complement binary representation of the specified
1812 * {@code long} value. Returns 64 if the specified value has no
1813 * one-bits in its two's complement representation, in other words if it is
1814 * equal to zero.
1815 *
1816 * @param i the value whose number of trailing zeros is to be computed
1817 * @return the number of zero bits following the lowest-order ("rightmost")
1818 * one-bit in the two's complement binary representation of the
1819 * specified {@code long} value, or 64 if the value is equal
1820 * to zero.
1821 * @since 1.5
1822 */
1823 @HotSpotIntrinsicCandidate
1824 public static int numberOfTrailingZeros(long i) {
1825 // HD, Figure 5-14
1826 int x, y;
1827 if (i == 0) return 64;
1828 int n = 63;
1829 y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
1830 y = x <<16; if (y != 0) { n = n -16; x = y; }
1831 y = x << 8; if (y != 0) { n = n - 8; x = y; }
1832 y = x << 4; if (y != 0) { n = n - 4; x = y; }
1833 y = x << 2; if (y != 0) { n = n - 2; x = y; }
1834 return n - ((x << 1) >>> 31);
1835 }
1836
1837 /**
1838 * Returns the number of one-bits in the two's complement binary
1839 * representation of the specified {@code long} value. This function is
1840 * sometimes referred to as the <i>population count</i>.
1841 *
1842 * @param i the value whose bits are to be counted
1843 * @return the number of one-bits in the two's complement binary
1844 * representation of the specified {@code long} value.
1845 * @since 1.5
1846 */
1847 @HotSpotIntrinsicCandidate
1848 public static int bitCount(long i) {
1849 // HD, Figure 5-2
1850 i = i - ((i >>> 1) & 0x5555555555555555L);
1851 i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
1852 i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
1853 i = i + (i >>> 8);
1854 i = i + (i >>> 16);
1855 i = i + (i >>> 32);
1856 return (int)i & 0x7f;
1857 }
1858
1859 /**
1860 * Returns the value obtained by rotating the two's complement binary
1861 * representation of the specified {@code long} value left by the
1862 * specified number of bits. (Bits shifted out of the left hand, or
1863 * high-order, side reenter on the right, or low-order.)
1864 *
1865 * <p>Note that left rotation with a negative distance is equivalent to
1866 * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
1867 * distance)}. Note also that rotation by any multiple of 64 is a
1868 * no-op, so all but the last six bits of the rotation distance can be
1869 * ignored, even if the distance is negative: {@code rotateLeft(val,
1870 * distance) == rotateLeft(val, distance & 0x3F)}.
1871 *
1872 * @param i the value whose bits are to be rotated left
1873 * @param distance the number of bit positions to rotate left
1874 * @return the value obtained by rotating the two's complement binary
1875 * representation of the specified {@code long} value left by the
1876 * specified number of bits.
1877 * @since 1.5
1878 */
1879 public static long rotateLeft(long i, int distance) {
1880 return (i << distance) | (i >>> -distance);
1881 }
1882
1883 /**
1884 * Returns the value obtained by rotating the two's complement binary
1885 * representation of the specified {@code long} value right by the
1886 * specified number of bits. (Bits shifted out of the right hand, or
1887 * low-order, side reenter on the left, or high-order.)
1888 *
1889 * <p>Note that right rotation with a negative distance is equivalent to
1890 * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
1891 * distance)}. Note also that rotation by any multiple of 64 is a
1892 * no-op, so all but the last six bits of the rotation distance can be
1893 * ignored, even if the distance is negative: {@code rotateRight(val,
1894 * distance) == rotateRight(val, distance & 0x3F)}.
1895 *
1896 * @param i the value whose bits are to be rotated right
1897 * @param distance the number of bit positions to rotate right
1898 * @return the value obtained by rotating the two's complement binary
1899 * representation of the specified {@code long} value right by the
1900 * specified number of bits.
1901 * @since 1.5
1902 */
1903 public static long rotateRight(long i, int distance) {
1904 return (i >>> distance) | (i << -distance);
1905 }
1906
1907 /**
1908 * Returns the value obtained by reversing the order of the bits in the
1909 * two's complement binary representation of the specified {@code long}
1910 * value.
1911 *
1912 * @param i the value to be reversed
1913 * @return the value obtained by reversing order of the bits in the
1914 * specified {@code long} value.
1915 * @since 1.5
1916 */
1917 public static long reverse(long i) {
1918 // HD, Figure 7-1
1919 i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
1920 i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
1921 i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
1922 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1923 i = (i << 48) | ((i & 0xffff0000L) << 16) |
1924 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1925 return i;
1926 }
1927
1928 /**
1929 * Returns the signum function of the specified {@code long} value. (The
1930 * return value is -1 if the specified value is negative; 0 if the
1931 * specified value is zero; and 1 if the specified value is positive.)
1932 *
1933 * @param i the value whose signum is to be computed
1934 * @return the signum function of the specified {@code long} value.
1935 * @since 1.5
1936 */
1937 public static int signum(long i) {
1938 // HD, Section 2-7
1939 return (int) ((i >> 63) | (-i >>> 63));
1940 }
1941
1942 /**
1943 * Returns the value obtained by reversing the order of the bytes in the
1944 * two's complement representation of the specified {@code long} value.
1945 *
1946 * @param i the value whose bytes are to be reversed
1947 * @return the value obtained by reversing the bytes in the specified
1948 * {@code long} value.
1949 * @since 1.5
1950 */
1951 @HotSpotIntrinsicCandidate
1952 public static long reverseBytes(long i) {
1953 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1954 return (i << 48) | ((i & 0xffff0000L) << 16) |
1955 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1956 }
1957
1958 /**
1959 * Adds two {@code long} values together as per the + operator.
1960 *
1961 * @param a the first operand
1962 * @param b the second operand
1963 * @return the sum of {@code a} and {@code b}
1964 * @see java.util.function.BinaryOperator
1965 * @since 1.8
1966 */
1967 public static long sum(long a, long b) {
1968 return a + b;
1969 }
1970
1971 /**
1972 * Returns the greater of two {@code long} values
1973 * as if by calling {@link Math#max(long, long) Math.max}.
1974 *
1975 * @param a the first operand
1976 * @param b the second operand
1977 * @return the greater of {@code a} and {@code b}
1978 * @see java.util.function.BinaryOperator
1979 * @since 1.8
1980 */
1981 public static long max(long a, long b) {
1982 return Math.max(a, b);
1983 }
1984
1985 /**
1986 * Returns the smaller of two {@code long} values
1987 * as if by calling {@link Math#min(long, long) Math.min}.
1988 *
1989 * @param a the first operand
1990 * @param b the second operand
1991 * @return the smaller of {@code a} and {@code b}
1992 * @see java.util.function.BinaryOperator
1993 * @since 1.8
1994 */
1995 public static long min(long a, long b) {
1996 return Math.min(a, b);
1997 }
1998
1999 /** use serialVersionUID from JDK 1.0.2 for interoperability */
2000 @Native private static final long serialVersionUID = 4290774380558885855L;
2001 }