1 /*
2 * Copyright (c) 1994, 2018, 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
405 /** byte[]/LATIN1 version */
406 static void formatUnsignedLong0(long val, int shift, byte[] buf, int offset, int len) {
407 int charPos = offset + len;
408 int radix = 1 << shift;
409 int mask = radix - 1;
410 do {
411 buf[--charPos] = (byte)Integer.digits[((int) val) & mask];
412 val >>>= shift;
413 } while (charPos > offset);
414 }
415
416 /** byte[]/UTF16 version */
417 private static void formatUnsignedLong0UTF16(long val, int shift, byte[] buf, int offset, int len) {
418 int charPos = offset + len;
419 int radix = 1 << shift;
420 int mask = radix - 1;
421 do {
422 StringUTF16.putChar(buf, --charPos, Integer.digits[((int) val) & mask]);
423 val >>>= shift;
424 } while (charPos > offset);
425 }
426
427 static String fastUUID(long lsb, long msb) {
428 if (COMPACT_STRINGS) {
429 byte[] buf = new byte[36];
430 formatUnsignedLong0(lsb, 4, buf, 24, 12);
431 formatUnsignedLong0(lsb >>> 48, 4, buf, 19, 4);
432 formatUnsignedLong0(msb, 4, buf, 14, 4);
433 formatUnsignedLong0(msb >>> 16, 4, buf, 9, 4);
434 formatUnsignedLong0(msb >>> 32, 4, buf, 0, 8);
435
436 buf[23] = '-';
437 buf[18] = '-';
438 buf[13] = '-';
439 buf[8] = '-';
440
441 return new String(buf, LATIN1);
442 } else {
443 byte[] buf = new byte[72];
444
445 formatUnsignedLong0UTF16(lsb, 4, buf, 24, 12);
446 formatUnsignedLong0UTF16(lsb >>> 48, 4, buf, 19, 4);
447 formatUnsignedLong0UTF16(msb, 4, buf, 14, 4);
448 formatUnsignedLong0UTF16(msb >>> 16, 4, buf, 9, 4);
449 formatUnsignedLong0UTF16(msb >>> 32, 4, buf, 0, 8);
450
451 StringUTF16.putChar(buf, 23, '-');
452 StringUTF16.putChar(buf, 18, '-');
453 StringUTF16.putChar(buf, 13, '-');
454 StringUTF16.putChar(buf, 8, '-');
455
456 return new String(buf, UTF16);
457 }
458 }
459
460 /**
461 * Returns a {@code String} object representing the specified
462 * {@code long}. The argument is converted to signed decimal
463 * representation and returned as a string, exactly as if the
464 * argument and the radix 10 were given as arguments to the {@link
465 * #toString(long, int)} method.
466 *
467 * @param i a {@code long} to be converted.
468 * @return a string representation of the argument in base 10.
469 */
470 public static String toString(long i) {
471 int size = stringSize(i);
472 if (COMPACT_STRINGS) {
473 byte[] buf = new byte[size];
474 getChars(i, size, buf);
475 return new String(buf, LATIN1);
476 } else {
477 byte[] buf = new byte[size * 2];
478 StringUTF16.getChars(i, size, buf);
479 return new String(buf, UTF16);
480 }
481 }
482
483 /**
484 * Returns a string representation of the argument as an unsigned
485 * decimal value.
486 *
487 * The argument is converted to unsigned decimal representation
488 * and returned as a string exactly as if the argument and radix
489 * 10 were given as arguments to the {@link #toUnsignedString(long,
490 * int)} method.
491 *
492 * @param i an integer to be converted to an unsigned string.
493 * @return an unsigned string representation of the argument.
494 * @see #toUnsignedString(long, int)
495 * @since 1.8
496 */
497 public static String toUnsignedString(long i) {
498 return toUnsignedString(i, 10);
499 }
500
501 /**
502 * Places characters representing the long i into the
503 * character array buf. The characters are placed into
504 * the buffer backwards starting with the least significant
505 * digit at the specified index (exclusive), and working
506 * backwards from there.
507 *
508 * @implNote This method converts positive inputs into negative
509 * values, to cover the Long.MIN_VALUE case. Converting otherwise
510 * (negative to positive) will expose -Long.MIN_VALUE that overflows
511 * long.
512 *
513 * @param i value to convert
514 * @param index next index, after the least significant digit
515 * @param buf target buffer, Latin1-encoded
516 * @return index of the most significant digit or minus sign, if present
517 */
518 static int getChars(long i, int index, byte[] buf) {
519 long q;
520 int r;
521 int charPos = index;
522
523 boolean negative = (i < 0);
524 if (!negative) {
525 i = -i;
526 }
527
528 // Get 2 digits/iteration using longs until quotient fits into an int
529 while (i <= Integer.MIN_VALUE) {
530 q = i / 100;
531 r = (int)((q * 100) - i);
532 i = q;
533 buf[--charPos] = Integer.DigitOnes[r];
534 buf[--charPos] = Integer.DigitTens[r];
535 }
536
537 // Get 2 digits/iteration using ints
538 int q2;
539 int i2 = (int)i;
540 while (i2 <= -100) {
541 q2 = i2 / 100;
542 r = (q2 * 100) - i2;
543 i2 = q2;
544 buf[--charPos] = Integer.DigitOnes[r];
545 buf[--charPos] = Integer.DigitTens[r];
546 }
547
548 // We know there are at most two digits left at this point.
549 q2 = i2 / 10;
550 r = (q2 * 10) - i2;
551 buf[--charPos] = (byte)('0' + r);
552
553 // Whatever left is the remaining digit.
554 if (q2 < 0) {
555 buf[--charPos] = (byte)('0' - q2);
556 }
557
558 if (negative) {
559 buf[--charPos] = (byte)'-';
560 }
561 return charPos;
562 }
563
564 /**
565 * Returns the string representation size for a given long value.
566 *
567 * @param x long value
568 * @return string size
569 *
570 * @implNote There are other ways to compute this: e.g. binary search,
571 * but values are biased heavily towards zero, and therefore linear search
572 * wins. The iteration results are also routinely inlined in the generated
573 * code after loop unrolling.
574 */
575 static int stringSize(long x) {
576 int d = 1;
577 if (x >= 0) {
578 d = 0;
579 x = -x;
580 }
581 long p = -10;
582 for (int i = 1; i < 19; i++) {
583 if (x > p)
584 return i + d;
585 p = 10 * p;
586 }
587 return 19 + d;
588 }
589
590 /**
591 * Parses the string argument as a signed {@code long} in the
592 * radix specified by the second argument. The characters in the
593 * string must all be digits of the specified radix (as determined
594 * by whether {@link java.lang.Character#digit(char, int)} returns
595 * a nonnegative value), except that the first character may be an
596 * ASCII minus sign {@code '-'} ({@code '\u005Cu002D'}) to
597 * indicate a negative value or an ASCII plus sign {@code '+'}
598 * ({@code '\u005Cu002B'}) to indicate a positive value. The
599 * resulting {@code long} value is returned.
600 *
601 * <p>Note that neither the character {@code L}
602 * ({@code '\u005Cu004C'}) nor {@code l}
603 * ({@code '\u005Cu006C'}) is permitted to appear at the end
604 * of the string as a type indicator, as would be permitted in
605 * Java programming language source code - except that either
606 * {@code L} or {@code l} may appear as a digit for a
607 * radix greater than or equal to 22.
608 *
609 * <p>An exception of type {@code NumberFormatException} is
610 * thrown if any of the following situations occurs:
611 * <ul>
612 *
613 * <li>The first argument is {@code null} or is a string of
614 * length zero.
615 *
616 * <li>The {@code radix} is either smaller than {@link
617 * java.lang.Character#MIN_RADIX} or larger than {@link
618 * java.lang.Character#MAX_RADIX}.
619 *
620 * <li>Any character of the string is not a digit of the specified
621 * radix, except that the first character may be a minus sign
622 * {@code '-'} ({@code '\u005Cu002d'}) or plus sign {@code
623 * '+'} ({@code '\u005Cu002B'}) provided that the string is
624 * longer than length 1.
625 *
626 * <li>The value represented by the string is not a value of type
627 * {@code long}.
628 * </ul>
629 *
630 * <p>Examples:
631 * <blockquote><pre>
632 * parseLong("0", 10) returns 0L
633 * parseLong("473", 10) returns 473L
634 * parseLong("+42", 10) returns 42L
635 * parseLong("-0", 10) returns 0L
636 * parseLong("-FF", 16) returns -255L
637 * parseLong("1100110", 2) returns 102L
638 * parseLong("99", 8) throws a NumberFormatException
639 * parseLong("Hazelnut", 10) throws a NumberFormatException
640 * parseLong("Hazelnut", 36) returns 1356099454469L
641 * </pre></blockquote>
642 *
643 * @param s the {@code String} containing the
644 * {@code long} representation to be parsed.
645 * @param radix the radix to be used while parsing {@code s}.
646 * @return the {@code long} represented by the string argument in
647 * the specified radix.
648 * @throws NumberFormatException if the string does not contain a
649 * parsable {@code long}.
650 */
651 public static long parseLong(String s, int radix)
652 throws NumberFormatException
653 {
654 if (s == null) {
655 throw new NumberFormatException("null");
656 }
657
658 if (radix < Character.MIN_RADIX) {
659 throw new NumberFormatException("radix " + radix +
660 " less than Character.MIN_RADIX");
661 }
662 if (radix > Character.MAX_RADIX) {
663 throw new NumberFormatException("radix " + radix +
664 " greater than Character.MAX_RADIX");
665 }
666
667 boolean negative = false;
668 int i = 0, len = s.length();
669 long limit = -Long.MAX_VALUE;
670
671 if (len > 0) {
672 char firstChar = s.charAt(0);
673 if (firstChar < '0') { // Possible leading "+" or "-"
674 if (firstChar == '-') {
675 negative = true;
676 limit = Long.MIN_VALUE;
677 } else if (firstChar != '+') {
678 throw NumberFormatException.forInputString(s);
679 }
680
681 if (len == 1) { // Cannot have lone "+" or "-"
682 throw NumberFormatException.forInputString(s);
683 }
684 i++;
685 }
686 long multmin = limit / radix;
687 long result = 0;
688 while (i < len) {
689 // Accumulating negatively avoids surprises near MAX_VALUE
690 int digit = Character.digit(s.charAt(i++),radix);
691 if (digit < 0 || result < multmin) {
692 throw NumberFormatException.forInputString(s);
693 }
694 result *= radix;
695 if (result < limit + digit) {
696 throw NumberFormatException.forInputString(s);
697 }
698 result -= digit;
699 }
700 return negative ? result : -result;
701 } else {
702 throw NumberFormatException.forInputString(s);
703 }
704 }
705
706 /**
707 * Parses the {@link CharSequence} argument as a signed {@code long} in
708 * the specified {@code radix}, beginning at the specified
709 * {@code beginIndex} and extending to {@code endIndex - 1}.
710 *
711 * <p>The method does not take steps to guard against the
712 * {@code CharSequence} being mutated while parsing.
713 *
714 * @param s the {@code CharSequence} containing the {@code long}
715 * representation to be parsed
716 * @param beginIndex the beginning index, inclusive.
717 * @param endIndex the ending index, exclusive.
718 * @param radix the radix to be used while parsing {@code s}.
719 * @return the signed {@code long} represented by the subsequence in
720 * the specified radix.
721 * @throws NullPointerException if {@code s} is null.
722 * @throws IndexOutOfBoundsException if {@code beginIndex} is
723 * negative, or if {@code beginIndex} is greater than
724 * {@code endIndex} or if {@code endIndex} is greater than
725 * {@code s.length()}.
726 * @throws NumberFormatException if the {@code CharSequence} does not
727 * contain a parsable {@code int} in the specified
728 * {@code radix}, or if {@code radix} is either smaller than
729 * {@link java.lang.Character#MIN_RADIX} or larger than
730 * {@link java.lang.Character#MAX_RADIX}.
731 * @since 9
732 */
733 public static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix)
734 throws NumberFormatException {
735 s = Objects.requireNonNull(s);
736
737 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
738 throw new IndexOutOfBoundsException();
739 }
740 if (radix < Character.MIN_RADIX) {
741 throw new NumberFormatException("radix " + radix +
742 " less than Character.MIN_RADIX");
743 }
744 if (radix > Character.MAX_RADIX) {
745 throw new NumberFormatException("radix " + radix +
746 " greater than Character.MAX_RADIX");
747 }
748
749 boolean negative = false;
750 int i = beginIndex;
751 long limit = -Long.MAX_VALUE;
752
753 if (i < endIndex) {
754 char firstChar = s.charAt(i);
755 if (firstChar < '0') { // Possible leading "+" or "-"
756 if (firstChar == '-') {
757 negative = true;
758 limit = Long.MIN_VALUE;
759 } else if (firstChar != '+') {
760 throw NumberFormatException.forCharSequence(s, beginIndex,
761 endIndex, i);
762 }
763 i++;
764 }
765 if (i >= endIndex) { // Cannot have lone "+", "-" or ""
766 throw NumberFormatException.forCharSequence(s, beginIndex,
767 endIndex, i);
768 }
769 long multmin = limit / radix;
770 long result = 0;
771 while (i < endIndex) {
772 // Accumulating negatively avoids surprises near MAX_VALUE
773 int digit = Character.digit(s.charAt(i), radix);
774 if (digit < 0 || result < multmin) {
775 throw NumberFormatException.forCharSequence(s, beginIndex,
776 endIndex, i);
777 }
778 result *= radix;
779 if (result < limit + digit) {
780 throw NumberFormatException.forCharSequence(s, beginIndex,
781 endIndex, i);
782 }
783 i++;
784 result -= digit;
785 }
786 return negative ? result : -result;
787 } else {
788 throw new NumberFormatException("");
789 }
790 }
791
792 /**
793 * Parses the string argument as a signed decimal {@code long}.
794 * The characters in the string must all be decimal digits, except
795 * that the first character may be an ASCII minus sign {@code '-'}
796 * ({@code \u005Cu002D'}) to indicate a negative value or an
797 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
798 * indicate a positive value. The resulting {@code long} value is
799 * returned, exactly as if the argument and the radix {@code 10}
800 * were given as arguments to the {@link
801 * #parseLong(java.lang.String, int)} method.
802 *
803 * <p>Note that neither the character {@code L}
804 * ({@code '\u005Cu004C'}) nor {@code l}
805 * ({@code '\u005Cu006C'}) is permitted to appear at the end
806 * of the string as a type indicator, as would be permitted in
807 * Java programming language source code.
808 *
809 * @param s a {@code String} containing the {@code long}
810 * representation to be parsed
811 * @return the {@code long} represented by the argument in
812 * decimal.
813 * @throws NumberFormatException if the string does not contain a
814 * parsable {@code long}.
815 */
816 public static long parseLong(String s) throws NumberFormatException {
817 return parseLong(s, 10);
818 }
819
820 /**
821 * Parses the string argument as an unsigned {@code long} in the
822 * radix specified by the second argument. An unsigned integer
823 * maps the values usually associated with negative numbers to
824 * positive numbers larger than {@code MAX_VALUE}.
825 *
826 * The characters in the string must all be digits of the
827 * specified radix (as determined by whether {@link
828 * java.lang.Character#digit(char, int)} returns a nonnegative
829 * value), except that the first character may be an ASCII plus
830 * sign {@code '+'} ({@code '\u005Cu002B'}). The resulting
831 * integer value is returned.
832 *
833 * <p>An exception of type {@code NumberFormatException} is
834 * thrown if any of the following situations occurs:
835 * <ul>
836 * <li>The first argument is {@code null} or is a string of
837 * length zero.
838 *
839 * <li>The radix is either smaller than
840 * {@link java.lang.Character#MIN_RADIX} or
841 * larger than {@link java.lang.Character#MAX_RADIX}.
842 *
843 * <li>Any character of the string is not a digit of the specified
844 * radix, except that the first character may be a plus sign
845 * {@code '+'} ({@code '\u005Cu002B'}) provided that the
846 * string is longer than length 1.
847 *
848 * <li>The value represented by the string is larger than the
849 * largest unsigned {@code long}, 2<sup>64</sup>-1.
850 *
851 * </ul>
852 *
853 *
854 * @param s the {@code String} containing the unsigned integer
855 * representation to be parsed
856 * @param radix the radix to be used while parsing {@code s}.
857 * @return the unsigned {@code long} represented by the string
858 * argument in the specified radix.
859 * @throws NumberFormatException if the {@code String}
860 * does not contain a parsable {@code long}.
861 * @since 1.8
862 */
863 public static long parseUnsignedLong(String s, int radix)
864 throws NumberFormatException {
865 if (s == null) {
866 throw new NumberFormatException("null");
867 }
868
869 int len = s.length();
870 if (len > 0) {
871 char firstChar = s.charAt(0);
872 if (firstChar == '-') {
873 throw new
874 NumberFormatException(String.format("Illegal leading minus sign " +
875 "on unsigned string %s.", s));
876 } else {
877 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
878 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
879 return parseLong(s, radix);
880 }
881
882 // No need for range checks on len due to testing above.
883 long first = parseLong(s, 0, len - 1, radix);
884 int second = Character.digit(s.charAt(len - 1), radix);
885 if (second < 0) {
886 throw new NumberFormatException("Bad digit at end of " + s);
887 }
888 long result = first * radix + second;
889
890 /*
891 * Test leftmost bits of multiprecision extension of first*radix
892 * for overflow. The number of bits needed is defined by
893 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
894 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
895 * overflow is tested by splitting guard in the ranges
896 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
897 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
898 * on a value which does not include a prime factor in the legal
899 * radix range.
900 */
901 int guard = radix * (int) (first >>> 57);
902 if (guard >= 128 ||
903 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
904 /*
905 * For purposes of exposition, the programmatic statements
906 * below should be taken to be multi-precision, i.e., not
907 * subject to overflow.
908 *
909 * A) Condition guard >= 128:
910 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
911 * hence always overflow.
912 *
913 * B) Condition guard < 92:
914 * Define left7 = first >>> 57.
915 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
916 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
917 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
918 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
919 * never overflow.
920 *
921 * C) Condition 92 <= guard < 128:
922 * first*radix + second >= radix*left7*2^57 + second
923 * so that first*radix + second >= 92*2^57 + 0 > 2^63
924 *
925 * D) Condition guard < 128:
926 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
927 * so
928 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
929 * thus
930 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
931 * whence
932 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
933 *
934 * E) Conditions C, D, and result >= 0:
935 * C and D combined imply the mathematical result
936 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
937 * bound is therefore negative as a signed long, but the
938 * upper bound is too small to overflow again after the
939 * signed long overflows to positive above 2^64 - 1. Hence
940 * result >= 0 implies overflow given C and D.
941 */
942 throw new NumberFormatException(String.format("String value %s exceeds " +
943 "range of unsigned long.", s));
944 }
945 return result;
946 }
947 } else {
948 throw NumberFormatException.forInputString(s);
949 }
950 }
951
952 /**
953 * Parses the {@link CharSequence} argument as an unsigned {@code long} in
954 * the specified {@code radix}, beginning at the specified
955 * {@code beginIndex} and extending to {@code endIndex - 1}.
956 *
957 * <p>The method does not take steps to guard against the
958 * {@code CharSequence} being mutated while parsing.
959 *
960 * @param s the {@code CharSequence} containing the unsigned
961 * {@code long} representation to be parsed
962 * @param beginIndex the beginning index, inclusive.
963 * @param endIndex the ending index, exclusive.
964 * @param radix the radix to be used while parsing {@code s}.
965 * @return the unsigned {@code long} represented by the subsequence in
966 * the specified radix.
967 * @throws NullPointerException if {@code s} is null.
968 * @throws IndexOutOfBoundsException if {@code beginIndex} is
969 * negative, or if {@code beginIndex} is greater than
970 * {@code endIndex} or if {@code endIndex} is greater than
971 * {@code s.length()}.
972 * @throws NumberFormatException if the {@code CharSequence} does not
973 * contain a parsable unsigned {@code long} in the specified
974 * {@code radix}, or if {@code radix} is either smaller than
975 * {@link java.lang.Character#MIN_RADIX} or larger than
976 * {@link java.lang.Character#MAX_RADIX}.
977 * @since 9
978 */
979 public static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix)
980 throws NumberFormatException {
981 s = Objects.requireNonNull(s);
982
983 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
984 throw new IndexOutOfBoundsException();
985 }
986 int start = beginIndex, len = endIndex - beginIndex;
987
988 if (len > 0) {
989 char firstChar = s.charAt(start);
990 if (firstChar == '-') {
991 throw new NumberFormatException(String.format("Illegal leading minus sign " +
992 "on unsigned string %s.", s.subSequence(start, start + len)));
993 } else {
994 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
995 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
996 return parseLong(s, start, start + len, radix);
997 }
998
999 // No need for range checks on end due to testing above.
1000 long first = parseLong(s, start, start + len - 1, radix);
1001 int second = Character.digit(s.charAt(start + len - 1), radix);
1002 if (second < 0) {
1003 throw new NumberFormatException("Bad digit at end of " +
1004 s.subSequence(start, start + len));
1005 }
1006 long result = first * radix + second;
1007
1008 /*
1009 * Test leftmost bits of multiprecision extension of first*radix
1010 * for overflow. The number of bits needed is defined by
1011 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
1012 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
1013 * overflow is tested by splitting guard in the ranges
1014 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
1015 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
1016 * on a value which does not include a prime factor in the legal
1017 * radix range.
1018 */
1019 int guard = radix * (int) (first >>> 57);
1020 if (guard >= 128 ||
1021 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
1022 /*
1023 * For purposes of exposition, the programmatic statements
1024 * below should be taken to be multi-precision, i.e., not
1025 * subject to overflow.
1026 *
1027 * A) Condition guard >= 128:
1028 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
1029 * hence always overflow.
1030 *
1031 * B) Condition guard < 92:
1032 * Define left7 = first >>> 57.
1033 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
1034 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
1035 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
1036 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
1037 * never overflow.
1038 *
1039 * C) Condition 92 <= guard < 128:
1040 * first*radix + second >= radix*left7*2^57 + second
1041 * so that first*radix + second >= 92*2^57 + 0 > 2^63
1042 *
1043 * D) Condition guard < 128:
1044 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
1045 * so
1046 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
1047 * thus
1048 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
1049 * whence
1050 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
1051 *
1052 * E) Conditions C, D, and result >= 0:
1053 * C and D combined imply the mathematical result
1054 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
1055 * bound is therefore negative as a signed long, but the
1056 * upper bound is too small to overflow again after the
1057 * signed long overflows to positive above 2^64 - 1. Hence
1058 * result >= 0 implies overflow given C and D.
1059 */
1060 throw new NumberFormatException(String.format("String value %s exceeds " +
1061 "range of unsigned long.", s.subSequence(start, start + len)));
1062 }
1063 return result;
1064 }
1065 } else {
1066 throw NumberFormatException.forInputString("");
1067 }
1068 }
1069
1070 /**
1071 * Parses the string argument as an unsigned decimal {@code long}. The
1072 * characters in the string must all be decimal digits, except
1073 * that the first character may be an ASCII plus sign {@code
1074 * '+'} ({@code '\u005Cu002B'}). The resulting integer value
1075 * is returned, exactly as if the argument and the radix 10 were
1076 * given as arguments to the {@link
1077 * #parseUnsignedLong(java.lang.String, int)} method.
1078 *
1079 * @param s a {@code String} containing the unsigned {@code long}
1080 * representation to be parsed
1081 * @return the unsigned {@code long} value represented by the decimal string argument
1082 * @throws NumberFormatException if the string does not contain a
1083 * parsable unsigned integer.
1084 * @since 1.8
1085 */
1086 public static long parseUnsignedLong(String s) throws NumberFormatException {
1087 return parseUnsignedLong(s, 10);
1088 }
1089
1090 /**
1091 * Returns a {@code Long} object holding the value
1092 * extracted from the specified {@code String} when parsed
1093 * with the radix given by the second argument. The first
1094 * argument is interpreted as representing a signed
1095 * {@code long} in the radix specified by the second
1096 * argument, exactly as if the arguments were given to the {@link
1097 * #parseLong(java.lang.String, int)} method. The result is a
1098 * {@code Long} object that represents the {@code long}
1099 * value specified by the string.
1100 *
1101 * <p>In other words, this method returns a {@code Long} object equal
1102 * to the value of:
1103 *
1104 * <blockquote>
1105 * {@code new Long(Long.parseLong(s, radix))}
1106 * </blockquote>
1107 *
1108 * @param s the string to be parsed
1109 * @param radix the radix to be used in interpreting {@code s}
1110 * @return a {@code Long} object holding the value
1111 * represented by the string argument in the specified
1112 * radix.
1113 * @throws NumberFormatException If the {@code String} does not
1114 * contain a parsable {@code long}.
1115 */
1116 public static Long valueOf(String s, int radix) throws NumberFormatException {
1117 return Long.valueOf(parseLong(s, radix));
1118 }
1119
1120 /**
1121 * Returns a {@code Long} object holding the value
1122 * of the specified {@code String}. The argument is
1123 * interpreted as representing a signed decimal {@code long},
1124 * exactly as if the argument were given to the {@link
1125 * #parseLong(java.lang.String)} method. The result is a
1126 * {@code Long} object that represents the integer value
1127 * specified by the string.
1128 *
1129 * <p>In other words, this method returns a {@code Long} object
1130 * equal to the value of:
1131 *
1132 * <blockquote>
1133 * {@code new Long(Long.parseLong(s))}
1134 * </blockquote>
1135 *
1136 * @param s the string to be parsed.
1137 * @return a {@code Long} object holding the value
1138 * represented by the string argument.
1139 * @throws NumberFormatException If the string cannot be parsed
1140 * as a {@code long}.
1141 */
1142 public static Long valueOf(String s) throws NumberFormatException
1143 {
1144 return Long.valueOf(parseLong(s, 10));
1145 }
1146
1147 private static class LongCache {
1148 private LongCache(){}
1149
1150 static final Long cache[] = new Long[-(-128) + 127 + 1];
1151
1152 static {
1153 for(int i = 0; i < cache.length; i++)
1154 cache[i] = new Long(i - 128);
1155 }
1156 }
1157
1158 /**
1159 * Returns a {@code Long} instance representing the specified
1160 * {@code long} value.
1161 * If a new {@code Long} instance is not required, this method
1162 * should generally be used in preference to the constructor
1163 * {@link #Long(long)}, as this method is likely to yield
1164 * significantly better space and time performance by caching
1165 * frequently requested values.
1166 *
1167 * Note that unlike the {@linkplain Integer#valueOf(int)
1168 * corresponding method} in the {@code Integer} class, this method
1169 * is <em>not</em> required to cache values within a particular
1170 * range.
1171 *
1172 * @param l a long value.
1173 * @return a {@code Long} instance representing {@code l}.
1174 * @since 1.5
1175 */
1176 @HotSpotIntrinsicCandidate
1177 public static Long valueOf(long l) {
1178 final int offset = 128;
1179 if (l >= -128 && l <= 127) { // will cache
1180 return LongCache.cache[(int)l + offset];
1181 }
1182 return new Long(l);
1183 }
1184
1185 /**
1186 * Decodes a {@code String} into a {@code Long}.
1187 * Accepts decimal, hexadecimal, and octal numbers given by the
1188 * following grammar:
1189 *
1190 * <blockquote>
1191 * <dl>
1192 * <dt><i>DecodableString:</i>
1193 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
1194 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
1195 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
1196 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
1197 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
1198 *
1199 * <dt><i>Sign:</i>
1200 * <dd>{@code -}
1201 * <dd>{@code +}
1202 * </dl>
1203 * </blockquote>
1204 *
1205 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
1206 * are as defined in section 3.10.1 of
1207 * <cite>The Java™ Language Specification</cite>,
1208 * except that underscores are not accepted between digits.
1209 *
1210 * <p>The sequence of characters following an optional
1211 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
1212 * "{@code #}", or leading zero) is parsed as by the {@code
1213 * Long.parseLong} method with the indicated radix (10, 16, or 8).
1214 * This sequence of characters must represent a positive value or
1215 * a {@link NumberFormatException} will be thrown. The result is
1216 * negated if first character of the specified {@code String} is
1217 * the minus sign. No whitespace characters are permitted in the
1218 * {@code String}.
1219 *
1220 * @param nm the {@code String} to decode.
1221 * @return a {@code Long} object holding the {@code long}
1222 * value represented by {@code nm}
1223 * @throws NumberFormatException if the {@code String} does not
1224 * contain a parsable {@code long}.
1225 * @see java.lang.Long#parseLong(String, int)
1226 * @since 1.2
1227 */
1228 public static Long decode(String nm) throws NumberFormatException {
1229 int radix = 10;
1230 int index = 0;
1231 boolean negative = false;
1232 Long result;
1233
1234 if (nm.length() == 0)
1235 throw new NumberFormatException("Zero length string");
1236 char firstChar = nm.charAt(0);
1237 // Handle sign, if present
1238 if (firstChar == '-') {
1239 negative = true;
1240 index++;
1241 } else if (firstChar == '+')
1242 index++;
1243
1244 // Handle radix specifier, if present
1245 if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
1246 index += 2;
1247 radix = 16;
1248 }
1249 else if (nm.startsWith("#", index)) {
1250 index ++;
1251 radix = 16;
1252 }
1253 else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
1254 index ++;
1255 radix = 8;
1256 }
1257
1258 if (nm.startsWith("-", index) || nm.startsWith("+", index))
1259 throw new NumberFormatException("Sign character in wrong position");
1260
1261 try {
1262 result = Long.valueOf(nm.substring(index), radix);
1263 result = negative ? Long.valueOf(-result.longValue()) : result;
1264 } catch (NumberFormatException e) {
1265 // If number is Long.MIN_VALUE, we'll end up here. The next line
1266 // handles this case, and causes any genuine format error to be
1267 // rethrown.
1268 String constant = negative ? ("-" + nm.substring(index))
1269 : nm.substring(index);
1270 result = Long.valueOf(constant, radix);
1271 }
1272 return result;
1273 }
1274
1275 /**
1276 * The value of the {@code Long}.
1277 *
1278 * @serial
1279 */
1280 private final long value;
1281
1282 /**
1283 * Constructs a newly allocated {@code Long} object that
1284 * represents the specified {@code long} argument.
1285 *
1286 * @param value the value to be represented by the
1287 * {@code Long} object.
1288 *
1289 * @deprecated
1290 * It is rarely appropriate to use this constructor. The static factory
1291 * {@link #valueOf(long)} is generally a better choice, as it is
1292 * likely to yield significantly better space and time performance.
1293 */
1294 @Deprecated(since="9")
1295 public Long(long value) {
1296 this.value = value;
1297 }
1298
1299 /**
1300 * Constructs a newly allocated {@code Long} object that
1301 * represents the {@code long} value indicated by the
1302 * {@code String} parameter. The string is converted to a
1303 * {@code long} value in exactly the manner used by the
1304 * {@code parseLong} method for radix 10.
1305 *
1306 * @param s the {@code String} to be converted to a
1307 * {@code Long}.
1308 * @throws NumberFormatException if the {@code String} does not
1309 * contain a parsable {@code long}.
1310 *
1311 * @deprecated
1312 * It is rarely appropriate to use this constructor.
1313 * Use {@link #parseLong(String)} to convert a string to a
1314 * {@code long} primitive, or use {@link #valueOf(String)}
1315 * to convert a string to a {@code Long} object.
1316 */
1317 @Deprecated(since="9")
1318 public Long(String s) throws NumberFormatException {
1319 this.value = parseLong(s, 10);
1320 }
1321
1322 /**
1323 * Returns the value of this {@code Long} as a {@code byte} after
1324 * a narrowing primitive conversion.
1325 * @jls 5.1.3 Narrowing Primitive Conversions
1326 */
1327 public byte byteValue() {
1328 return (byte)value;
1329 }
1330
1331 /**
1332 * Returns the value of this {@code Long} as a {@code short} after
1333 * a narrowing primitive conversion.
1334 * @jls 5.1.3 Narrowing Primitive Conversions
1335 */
1336 public short shortValue() {
1337 return (short)value;
1338 }
1339
1340 /**
1341 * Returns the value of this {@code Long} as an {@code int} after
1342 * a narrowing primitive conversion.
1343 * @jls 5.1.3 Narrowing Primitive Conversions
1344 */
1345 public int intValue() {
1346 return (int)value;
1347 }
1348
1349 /**
1350 * Returns the value of this {@code Long} as a
1351 * {@code long} value.
1352 */
1353 @HotSpotIntrinsicCandidate
1354 public long longValue() {
1355 return value;
1356 }
1357
1358 /**
1359 * Returns the value of this {@code Long} as a {@code float} after
1360 * a widening primitive conversion.
1361 * @jls 5.1.2 Widening Primitive Conversions
1362 */
1363 public float floatValue() {
1364 return (float)value;
1365 }
1366
1367 /**
1368 * Returns the value of this {@code Long} as a {@code double}
1369 * after a widening primitive conversion.
1370 * @jls 5.1.2 Widening Primitive Conversions
1371 */
1372 public double doubleValue() {
1373 return (double)value;
1374 }
1375
1376 /**
1377 * Returns a {@code String} object representing this
1378 * {@code Long}'s value. The value is converted to signed
1379 * decimal representation and returned as a string, exactly as if
1380 * the {@code long} value were given as an argument to the
1381 * {@link java.lang.Long#toString(long)} method.
1382 *
1383 * @return a string representation of the value of this object in
1384 * base 10.
1385 */
1386 public String toString() {
1387 return toString(value);
1388 }
1389
1390 /**
1391 * Returns a hash code for this {@code Long}. The result is
1392 * the exclusive OR of the two halves of the primitive
1393 * {@code long} value held by this {@code Long}
1394 * object. That is, the hashcode is the value of the expression:
1395 *
1396 * <blockquote>
1397 * {@code (int)(this.longValue()^(this.longValue()>>>32))}
1398 * </blockquote>
1399 *
1400 * @return a hash code value for this object.
1401 */
1402 @Override
1403 public int hashCode() {
1404 return Long.hashCode(value);
1405 }
1406
1407 /**
1408 * Returns a hash code for a {@code long} value; compatible with
1409 * {@code Long.hashCode()}.
1410 *
1411 * @param value the value to hash
1412 * @return a hash code value for a {@code long} value.
1413 * @since 1.8
1414 */
1415 public static int hashCode(long value) {
1416 return (int)(value ^ (value >>> 32));
1417 }
1418
1419 /**
1420 * Compares this object to the specified object. The result is
1421 * {@code true} if and only if the argument is not
1422 * {@code null} and is a {@code Long} object that
1423 * contains the same {@code long} value as this object.
1424 *
1425 * @param obj the object to compare with.
1426 * @return {@code true} if the objects are the same;
1427 * {@code false} otherwise.
1428 */
1429 public boolean equals(Object obj) {
1430 if (obj instanceof Long) {
1431 return value == ((Long)obj).longValue();
1432 }
1433 return false;
1434 }
1435
1436 /**
1437 * Determines the {@code long} value of the system property
1438 * with the specified name.
1439 *
1440 * <p>The first argument is treated as the name of a system
1441 * property. System properties are accessible through the {@link
1442 * java.lang.System#getProperty(java.lang.String)} method. The
1443 * string value of this property is then interpreted as a {@code
1444 * long} value using the grammar supported by {@link Long#decode decode}
1445 * and a {@code Long} object representing this value is returned.
1446 *
1447 * <p>If there is no property with the specified name, if the
1448 * specified name is empty or {@code null}, or if the property
1449 * does not have the correct numeric format, then {@code null} is
1450 * returned.
1451 *
1452 * <p>In other words, this method returns a {@code Long} object
1453 * equal to the value of:
1454 *
1455 * <blockquote>
1456 * {@code getLong(nm, null)}
1457 * </blockquote>
1458 *
1459 * @param nm property name.
1460 * @return the {@code Long} value of the property.
1461 * @throws SecurityException for the same reasons as
1462 * {@link System#getProperty(String) System.getProperty}
1463 * @see java.lang.System#getProperty(java.lang.String)
1464 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1465 */
1466 public static Long getLong(String nm) {
1467 return getLong(nm, null);
1468 }
1469
1470 /**
1471 * Determines the {@code long} value of the system property
1472 * with the specified name.
1473 *
1474 * <p>The first argument is treated as the name of a system
1475 * property. System properties are accessible through the {@link
1476 * java.lang.System#getProperty(java.lang.String)} method. The
1477 * string value of this property is then interpreted as a {@code
1478 * long} value using the grammar supported by {@link Long#decode decode}
1479 * and a {@code Long} object representing this value is returned.
1480 *
1481 * <p>The second argument is the default value. A {@code Long} object
1482 * that represents the value of the second argument is returned if there
1483 * is no property of the specified name, if the property does not have
1484 * the correct numeric format, or if the specified name is empty or null.
1485 *
1486 * <p>In other words, this method returns a {@code Long} object equal
1487 * to the value of:
1488 *
1489 * <blockquote>
1490 * {@code getLong(nm, new Long(val))}
1491 * </blockquote>
1492 *
1493 * but in practice it may be implemented in a manner such as:
1494 *
1495 * <blockquote><pre>
1496 * Long result = getLong(nm, null);
1497 * return (result == null) ? new Long(val) : result;
1498 * </pre></blockquote>
1499 *
1500 * to avoid the unnecessary allocation of a {@code Long} object when
1501 * the default value is not needed.
1502 *
1503 * @param nm property name.
1504 * @param val default value.
1505 * @return the {@code Long} value of the property.
1506 * @throws SecurityException for the same reasons as
1507 * {@link System#getProperty(String) System.getProperty}
1508 * @see java.lang.System#getProperty(java.lang.String)
1509 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1510 */
1511 public static Long getLong(String nm, long val) {
1512 Long result = Long.getLong(nm, null);
1513 return (result == null) ? Long.valueOf(val) : result;
1514 }
1515
1516 /**
1517 * Returns the {@code long} value of the system property with
1518 * the specified name. The first argument is treated as the name
1519 * of a system property. System properties are accessible through
1520 * the {@link java.lang.System#getProperty(java.lang.String)}
1521 * method. The string value of this property is then interpreted
1522 * as a {@code long} value, as per the
1523 * {@link Long#decode decode} method, and a {@code Long} object
1524 * representing this value is returned; in summary:
1525 *
1526 * <ul>
1527 * <li>If the property value begins with the two ASCII characters
1528 * {@code 0x} or the ASCII character {@code #}, not followed by
1529 * a minus sign, then the rest of it is parsed as a hexadecimal integer
1530 * exactly as for the method {@link #valueOf(java.lang.String, int)}
1531 * with radix 16.
1532 * <li>If the property value begins with the ASCII character
1533 * {@code 0} followed by another character, it is parsed as
1534 * an octal integer exactly as by the method {@link
1535 * #valueOf(java.lang.String, int)} with radix 8.
1536 * <li>Otherwise the property value is parsed as a decimal
1537 * integer exactly as by the method
1538 * {@link #valueOf(java.lang.String, int)} with radix 10.
1539 * </ul>
1540 *
1541 * <p>Note that, in every case, neither {@code L}
1542 * ({@code '\u005Cu004C'}) nor {@code l}
1543 * ({@code '\u005Cu006C'}) is permitted to appear at the end
1544 * of the property value as a type indicator, as would be
1545 * permitted in Java programming language source code.
1546 *
1547 * <p>The second argument is the default value. The default value is
1548 * returned if there is no property of the specified name, if the
1549 * property does not have the correct numeric format, or if the
1550 * specified name is empty or {@code null}.
1551 *
1552 * @param nm property name.
1553 * @param val default value.
1554 * @return the {@code Long} value of the property.
1555 * @throws SecurityException for the same reasons as
1556 * {@link System#getProperty(String) System.getProperty}
1557 * @see System#getProperty(java.lang.String)
1558 * @see System#getProperty(java.lang.String, java.lang.String)
1559 */
1560 public static Long getLong(String nm, Long val) {
1561 String v = null;
1562 try {
1563 v = System.getProperty(nm);
1564 } catch (IllegalArgumentException | NullPointerException e) {
1565 }
1566 if (v != null) {
1567 try {
1568 return Long.decode(v);
1569 } catch (NumberFormatException e) {
1570 }
1571 }
1572 return val;
1573 }
1574
1575 /**
1576 * Compares two {@code Long} objects numerically.
1577 *
1578 * @param anotherLong the {@code Long} to be compared.
1579 * @return the value {@code 0} if this {@code Long} is
1580 * equal to the argument {@code Long}; a value less than
1581 * {@code 0} if this {@code Long} is numerically less
1582 * than the argument {@code Long}; and a value greater
1583 * than {@code 0} if this {@code Long} is numerically
1584 * greater than the argument {@code Long} (signed
1585 * comparison).
1586 * @since 1.2
1587 */
1588 public int compareTo(Long anotherLong) {
1589 return compare(this.value, anotherLong.value);
1590 }
1591
1592 /**
1593 * Compares two {@code long} values numerically.
1594 * The value returned is identical to what would be returned by:
1595 * <pre>
1596 * Long.valueOf(x).compareTo(Long.valueOf(y))
1597 * </pre>
1598 *
1599 * @param x the first {@code long} to compare
1600 * @param y the second {@code long} to compare
1601 * @return the value {@code 0} if {@code x == y};
1602 * a value less than {@code 0} if {@code x < y}; and
1603 * a value greater than {@code 0} if {@code x > y}
1604 * @since 1.7
1605 */
1606 public static int compare(long x, long y) {
1607 return (x < y) ? -1 : ((x == y) ? 0 : 1);
1608 }
1609
1610 /**
1611 * Compares two {@code long} values numerically treating the values
1612 * as unsigned.
1613 *
1614 * @param x the first {@code long} to compare
1615 * @param y the second {@code long} to compare
1616 * @return the value {@code 0} if {@code x == y}; a value less
1617 * than {@code 0} if {@code x < y} as unsigned values; and
1618 * a value greater than {@code 0} if {@code x > y} as
1619 * unsigned values
1620 * @since 1.8
1621 */
1622 public static int compareUnsigned(long x, long y) {
1623 return compare(x + MIN_VALUE, y + MIN_VALUE);
1624 }
1625
1626
1627 /**
1628 * Returns the unsigned quotient of dividing the first argument by
1629 * the second where each argument and the result is interpreted as
1630 * an unsigned value.
1631 *
1632 * <p>Note that in two's complement arithmetic, the three other
1633 * basic arithmetic operations of add, subtract, and multiply are
1634 * bit-wise identical if the two operands are regarded as both
1635 * being signed or both being unsigned. Therefore separate {@code
1636 * addUnsigned}, etc. methods are not provided.
1637 *
1638 * @param dividend the value to be divided
1639 * @param divisor the value doing the dividing
1640 * @return the unsigned quotient of the first argument divided by
1641 * the second argument
1642 * @see #remainderUnsigned
1643 * @since 1.8
1644 */
1645 public static long divideUnsigned(long dividend, long divisor) {
1646 if (divisor < 0L) { // signed comparison
1647 // Answer must be 0 or 1 depending on relative magnitude
1648 // of dividend and divisor.
1649 return (compareUnsigned(dividend, divisor)) < 0 ? 0L :1L;
1650 }
1651
1652 if (dividend > 0) // Both inputs non-negative
1653 return dividend/divisor;
1654 else {
1655 /*
1656 * For simple code, leveraging BigInteger. Longer and faster
1657 * code written directly in terms of operations on longs is
1658 * possible; see "Hacker's Delight" for divide and remainder
1659 * algorithms.
1660 */
1661 return toUnsignedBigInteger(dividend).
1662 divide(toUnsignedBigInteger(divisor)).longValue();
1663 }
1664 }
1665
1666 /**
1667 * Returns the unsigned remainder from dividing the first argument
1668 * by the second where each argument and the result is interpreted
1669 * as an unsigned value.
1670 *
1671 * @param dividend the value to be divided
1672 * @param divisor the value doing the dividing
1673 * @return the unsigned remainder of the first argument divided by
1674 * the second argument
1675 * @see #divideUnsigned
1676 * @since 1.8
1677 */
1678 public static long remainderUnsigned(long dividend, long divisor) {
1679 if (dividend > 0 && divisor > 0) { // signed comparisons
1680 return dividend % divisor;
1681 } else {
1682 if (compareUnsigned(dividend, divisor) < 0) // Avoid explicit check for 0 divisor
1683 return dividend;
1684 else
1685 return toUnsignedBigInteger(dividend).
1686 remainder(toUnsignedBigInteger(divisor)).longValue();
1687 }
1688 }
1689
1690 // Bit Twiddling
1691
1692 /**
1693 * The number of bits used to represent a {@code long} value in two's
1694 * complement binary form.
1695 *
1696 * @since 1.5
1697 */
1698 @Native public static final int SIZE = 64;
1699
1700 /**
1701 * The number of bytes used to represent a {@code long} value in two's
1702 * complement binary form.
1703 *
1704 * @since 1.8
1705 */
1706 public static final int BYTES = SIZE / Byte.SIZE;
1707
1708 /**
1709 * Returns a {@code long} value with at most a single one-bit, in the
1710 * position of the highest-order ("leftmost") one-bit in the specified
1711 * {@code long} value. Returns zero if the specified value has no
1712 * one-bits in its two's complement binary representation, that is, if it
1713 * is equal to zero.
1714 *
1715 * @param i the value whose highest one bit is to be computed
1716 * @return a {@code long} value with a single one-bit, in the position
1717 * of the highest-order one-bit in the specified value, or zero if
1718 * the specified value is itself equal to zero.
1719 * @since 1.5
1720 */
1721 public static long highestOneBit(long i) {
1722 // HD, Figure 3-1
1723 i |= (i >> 1);
1724 i |= (i >> 2);
1725 i |= (i >> 4);
1726 i |= (i >> 8);
1727 i |= (i >> 16);
1728 i |= (i >> 32);
1729 return i - (i >>> 1);
1730 }
1731
1732 /**
1733 * Returns a {@code long} value with at most a single one-bit, in the
1734 * position of the lowest-order ("rightmost") one-bit in the specified
1735 * {@code long} value. Returns zero if the specified value has no
1736 * one-bits in its two's complement binary representation, that is, if it
1737 * is equal to zero.
1738 *
1739 * @param i the value whose lowest one bit is to be computed
1740 * @return a {@code long} value with a single one-bit, in the position
1741 * of the lowest-order one-bit in the specified value, or zero if
1742 * the specified value is itself equal to zero.
1743 * @since 1.5
1744 */
1745 public static long lowestOneBit(long i) {
1746 // HD, Section 2-1
1747 return i & -i;
1748 }
1749
1750 /**
1751 * Returns the number of zero bits preceding the highest-order
1752 * ("leftmost") one-bit in the two's complement binary representation
1753 * of the specified {@code long} value. Returns 64 if the
1754 * specified value has no one-bits in its two's complement representation,
1755 * in other words if it is equal to zero.
1756 *
1757 * <p>Note that this method is closely related to the logarithm base 2.
1758 * For all positive {@code long} values x:
1759 * <ul>
1760 * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}
1761 * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}
1762 * </ul>
1763 *
1764 * @param i the value whose number of leading zeros is to be computed
1765 * @return the number of zero bits preceding the highest-order
1766 * ("leftmost") one-bit in the two's complement binary representation
1767 * of the specified {@code long} value, or 64 if the value
1768 * is equal to zero.
1769 * @since 1.5
1770 */
1771 @HotSpotIntrinsicCandidate
1772 public static int numberOfLeadingZeros(long i) {
1773 // HD, Figure 5-6
1774 if (i <= 0)
1775 return i == 0 ? 64 : 0;
1776 int n = 1;
1777 int x = (int)(i >>> 32);
1778 if (x == 0) { n += 32; x = (int)i; }
1779 if (x >>> 16 == 0) { n += 16; x <<= 16; }
1780 if (x >>> 24 == 0) { n += 8; x <<= 8; }
1781 if (x >>> 28 == 0) { n += 4; x <<= 4; }
1782 if (x >>> 30 == 0) { n += 2; x <<= 2; }
1783 n -= x >>> 31;
1784 return n;
1785 }
1786
1787 /**
1788 * Returns the number of zero bits following the lowest-order ("rightmost")
1789 * one-bit in the two's complement binary representation of the specified
1790 * {@code long} value. Returns 64 if the specified value has no
1791 * one-bits in its two's complement representation, in other words if it is
1792 * equal to zero.
1793 *
1794 * @param i the value whose number of trailing zeros is to be computed
1795 * @return the number of zero bits following the lowest-order ("rightmost")
1796 * one-bit in the two's complement binary representation of the
1797 * specified {@code long} value, or 64 if the value is equal
1798 * to zero.
1799 * @since 1.5
1800 */
1801 @HotSpotIntrinsicCandidate
1802 public static int numberOfTrailingZeros(long i) {
1803 // HD, Figure 5-14
1804 int x, y;
1805 if (i == 0) return 64;
1806 int n = 63;
1807 y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
1808 y = x <<16; if (y != 0) { n = n -16; x = y; }
1809 y = x << 8; if (y != 0) { n = n - 8; x = y; }
1810 y = x << 4; if (y != 0) { n = n - 4; x = y; }
1811 y = x << 2; if (y != 0) { n = n - 2; x = y; }
1812 return n - ((x << 1) >>> 31);
1813 }
1814
1815 /**
1816 * Returns the number of one-bits in the two's complement binary
1817 * representation of the specified {@code long} value. This function is
1818 * sometimes referred to as the <i>population count</i>.
1819 *
1820 * @param i the value whose bits are to be counted
1821 * @return the number of one-bits in the two's complement binary
1822 * representation of the specified {@code long} value.
1823 * @since 1.5
1824 */
1825 @HotSpotIntrinsicCandidate
1826 public static int bitCount(long i) {
1827 // HD, Figure 5-2
1828 i = i - ((i >>> 1) & 0x5555555555555555L);
1829 i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
1830 i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
1831 i = i + (i >>> 8);
1832 i = i + (i >>> 16);
1833 i = i + (i >>> 32);
1834 return (int)i & 0x7f;
1835 }
1836
1837 /**
1838 * Returns the value obtained by rotating the two's complement binary
1839 * representation of the specified {@code long} value left by the
1840 * specified number of bits. (Bits shifted out of the left hand, or
1841 * high-order, side reenter on the right, or low-order.)
1842 *
1843 * <p>Note that left rotation with a negative distance is equivalent to
1844 * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
1845 * distance)}. Note also that rotation by any multiple of 64 is a
1846 * no-op, so all but the last six bits of the rotation distance can be
1847 * ignored, even if the distance is negative: {@code rotateLeft(val,
1848 * distance) == rotateLeft(val, distance & 0x3F)}.
1849 *
1850 * @param i the value whose bits are to be rotated left
1851 * @param distance the number of bit positions to rotate left
1852 * @return the value obtained by rotating the two's complement binary
1853 * representation of the specified {@code long} value left by the
1854 * specified number of bits.
1855 * @since 1.5
1856 */
1857 public static long rotateLeft(long i, int distance) {
1858 return (i << distance) | (i >>> -distance);
1859 }
1860
1861 /**
1862 * Returns the value obtained by rotating the two's complement binary
1863 * representation of the specified {@code long} value right by the
1864 * specified number of bits. (Bits shifted out of the right hand, or
1865 * low-order, side reenter on the left, or high-order.)
1866 *
1867 * <p>Note that right rotation with a negative distance is equivalent to
1868 * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
1869 * distance)}. Note also that rotation by any multiple of 64 is a
1870 * no-op, so all but the last six bits of the rotation distance can be
1871 * ignored, even if the distance is negative: {@code rotateRight(val,
1872 * distance) == rotateRight(val, distance & 0x3F)}.
1873 *
1874 * @param i the value whose bits are to be rotated right
1875 * @param distance the number of bit positions to rotate right
1876 * @return the value obtained by rotating the two's complement binary
1877 * representation of the specified {@code long} value right by the
1878 * specified number of bits.
1879 * @since 1.5
1880 */
1881 public static long rotateRight(long i, int distance) {
1882 return (i >>> distance) | (i << -distance);
1883 }
1884
1885 /**
1886 * Returns the value obtained by reversing the order of the bits in the
1887 * two's complement binary representation of the specified {@code long}
1888 * value.
1889 *
1890 * @param i the value to be reversed
1891 * @return the value obtained by reversing order of the bits in the
1892 * specified {@code long} value.
1893 * @since 1.5
1894 */
1895 public static long reverse(long i) {
1896 // HD, Figure 7-1
1897 i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
1898 i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
1899 i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
1900
1901 return reverseBytes(i);
1902 }
1903
1904 /**
1905 * Returns the signum function of the specified {@code long} value. (The
1906 * return value is -1 if the specified value is negative; 0 if the
1907 * specified value is zero; and 1 if the specified value is positive.)
1908 *
1909 * @param i the value whose signum is to be computed
1910 * @return the signum function of the specified {@code long} value.
1911 * @since 1.5
1912 */
1913 public static int signum(long i) {
1914 // HD, Section 2-7
1915 return (int) ((i >> 63) | (-i >>> 63));
1916 }
1917
1918 /**
1919 * Returns the value obtained by reversing the order of the bytes in the
1920 * two's complement representation of the specified {@code long} value.
1921 *
1922 * @param i the value whose bytes are to be reversed
1923 * @return the value obtained by reversing the bytes in the specified
1924 * {@code long} value.
1925 * @since 1.5
1926 */
1927 @HotSpotIntrinsicCandidate
1928 public static long reverseBytes(long i) {
1929 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1930 return (i << 48) | ((i & 0xffff0000L) << 16) |
1931 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1932 }
1933
1934 /**
1935 * Adds two {@code long} values together as per the + operator.
1936 *
1937 * @param a the first operand
1938 * @param b the second operand
1939 * @return the sum of {@code a} and {@code b}
1940 * @see java.util.function.BinaryOperator
1941 * @since 1.8
1942 */
1943 public static long sum(long a, long b) {
1944 return a + b;
1945 }
1946
1947 /**
1948 * Returns the greater of two {@code long} values
1949 * as if by calling {@link Math#max(long, long) Math.max}.
1950 *
1951 * @param a the first operand
1952 * @param b the second operand
1953 * @return the greater of {@code a} and {@code b}
1954 * @see java.util.function.BinaryOperator
1955 * @since 1.8
1956 */
1957 public static long max(long a, long b) {
1958 return Math.max(a, b);
1959 }
1960
1961 /**
1962 * Returns the smaller of two {@code long} values
1963 * as if by calling {@link Math#min(long, long) Math.min}.
1964 *
1965 * @param a the first operand
1966 * @param b the second operand
1967 * @return the smaller of {@code a} and {@code b}
1968 * @see java.util.function.BinaryOperator
1969 * @since 1.8
1970 */
1971 public static long min(long a, long b) {
1972 return Math.min(a, b);
1973 }
1974
1975 /** use serialVersionUID from JDK 1.0.2 for interoperability */
1976 @Native private static final long serialVersionUID = 4290774380558885855L;
1977 }