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
383 if (COMPACT_STRINGS) {
384 byte[] buf = new byte[chars];
385 formatUnsignedLong0(val, shift, buf, 0, chars);
386 return new String(buf, LATIN1);
387 } else {
388 byte[] buf = new byte[chars * 2];
389 formatUnsignedLong0UTF16(val, shift, buf, 0, chars);
390 return new String(buf, UTF16);
391 }
392 }
393
394 /**
395 * Format a long (treated as unsigned) into a character buffer. If
396 * {@code len} exceeds the formatted ASCII representation of {@code val},
397 * {@code buf} will be padded with leading zeroes.
398 *
399 * @param val the unsigned long to format
400 * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
401 * @param buf the character buffer to write to
402 * @param offset the offset in the destination buffer to start at
403 * @param len the number of characters to write
404 */
405 static void formatUnsignedLong(long val, int shift, char[] buf, int offset, int len) {
406 // assert shift > 0 && shift <=5 : "Illegal shift value";
407 // assert offset >= 0 && offset < buf.length : "illegal offset";
408 // assert len > 0 && (offset + len) <= buf.length : "illegal length";
409 int charPos = offset + len;
410 int radix = 1 << shift;
411 int mask = radix - 1;
412 do {
413 buf[--charPos] = Integer.digits[((int) val) & mask];
414 val >>>= shift;
415 } while (charPos > offset);
416 }
417
418 /** byte[]/LATIN1 version */
419 static void formatUnsignedLong0(long val, int shift, byte[] buf, int offset, int len) {
420 int charPos = offset + len;
421 int radix = 1 << shift;
422 int mask = radix - 1;
423 do {
424 buf[--charPos] = (byte)Integer.digits[((int) val) & mask];
425 val >>>= shift;
426 } while (charPos > offset);
427 }
428
429 /** byte[]/UTF16 version */
430 static void formatUnsignedLong0UTF16(long val, int shift, byte[] buf, int offset, int len) {
431 int charPos = offset + len;
432 int radix = 1 << shift;
433 int mask = radix - 1;
434 do {
435 StringUTF16.putChar(buf, --charPos, Integer.digits[((int) val) & mask]);
436 val >>>= shift;
437 } while (charPos > offset);
438 }
439
440 /**
441 * Returns a {@code String} object representing the specified
442 * {@code long}. The argument is converted to signed decimal
443 * representation and returned as a string, exactly as if the
444 * argument and the radix 10 were given as arguments to the {@link
445 * #toString(long, int)} method.
446 *
447 * @param i a {@code long} to be converted.
448 * @return a string representation of the argument in base 10.
449 */
450 public static String toString(long i) {
451 if (i == Long.MIN_VALUE)
452 return "-9223372036854775808";
453 int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
454 if (COMPACT_STRINGS) {
455 byte[] buf = new byte[size];
456 getChars(i, size, buf);
457 return new String(buf, LATIN1);
458 } else {
459 byte[] buf = new byte[size * 2];
460 getCharsUTF16(i, size, buf);
461 return new String(buf, UTF16);
462 }
463 }
464
465 /**
466 * Returns a string representation of the argument as an unsigned
467 * decimal value.
468 *
469 * The argument is converted to unsigned decimal representation
470 * and returned as a string exactly as if the argument and radix
471 * 10 were given as arguments to the {@link #toUnsignedString(long,
472 * int)} method.
473 *
474 * @param i an integer to be converted to an unsigned string.
475 * @return an unsigned string representation of the argument.
476 * @see #toUnsignedString(long, int)
477 * @since 1.8
478 */
479 public static String toUnsignedString(long i) {
480 return toUnsignedString(i, 10);
481 }
482
483 /**
484 * Places characters representing the integer i into the
485 * character array buf. The characters are placed into
486 * the buffer backwards starting with the least significant
487 * digit at the specified index (exclusive), and working
488 * backwards from there.
489 *
490 * Will fail if i == Long.MIN_VALUE
491 */
492 static void getChars(long i, int index, byte[] buf) {
493 long q;
494 int r;
495 int charPos = index;
496 char sign = 0;
497
498 if (i < 0) {
499 sign = '-';
500 i = -i;
501 }
502
503 // Get 2 digits/iteration using longs until quotient fits into an int
504 while (i > Integer.MAX_VALUE) {
505 q = i / 100;
506 // really: r = i - (q * 100);
507 r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
508 i = q;
509 buf[--charPos] = (byte)Integer.DigitOnes[r];
510 buf[--charPos] = (byte)Integer.DigitTens[r];
511 }
512
513 // Get 2 digits/iteration using ints
514 int q2;
515 int i2 = (int)i;
516 while (i2 >= 65536) {
517 q2 = i2 / 100;
518 // really: r = i2 - (q * 100);
519 r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
520 i2 = q2;
521 buf[--charPos] = (byte)Integer.DigitOnes[r];
522 buf[--charPos] = (byte)Integer.DigitTens[r];
523 }
524
525 // Fall thru to fast mode for smaller numbers
526 // assert(i2 <= 65536, i2);
527 for (;;) {
528 q2 = (i2 * 52429) >>> (16+3);
529 r = i2 - ((q2 << 3) + (q2 << 1)); // r = i2-(q2*10) ...
530 buf[--charPos] = (byte)Integer.digits[r];
531 i2 = q2;
532 if (i2 == 0) break;
533 }
534 if (sign != 0) {
535 buf[--charPos] = (byte)sign;
536 }
537 }
538
539 static void getCharsUTF16(long i, int index, byte[] buf) {
540 long q;
541 int r;
542 int charPos = index;
543 char sign = 0;
544
545 if (i < 0) {
546 sign = '-';
547 i = -i;
548 }
549
550 // Get 2 digits/iteration using longs until quotient fits into an int
551 while (i > Integer.MAX_VALUE) {
552 q = i / 100;
553 // really: r = i - (q * 100);
554 r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
555 i = q;
556 StringUTF16.putChar(buf, --charPos, Integer.DigitOnes[r]);
557 StringUTF16.putChar(buf, --charPos, Integer.DigitTens[r]);
558 }
559
560 // Get 2 digits/iteration using ints
561 int q2;
562 int i2 = (int)i;
563 while (i2 >= 65536) {
564 q2 = i2 / 100;
565 // really: r = i2 - (q * 100);
566 r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
567 i2 = q2;
568 StringUTF16.putChar(buf, --charPos, Integer.DigitOnes[r]);
569 StringUTF16.putChar(buf, --charPos, Integer.DigitTens[r]);
570 }
571
572 // Fall thru to fast mode for smaller numbers
573 // assert(i2 <= 65536, i2);
574 for (;;) {
575 q2 = (i2 * 52429) >>> (16+3);
576 r = i2 - ((q2 << 3) + (q2 << 1)); // r = i2-(q2*10) ...
577 StringUTF16.putChar(buf, --charPos, Integer.digits[r]);
578 i2 = q2;
579 if (i2 == 0) break;
580 }
581 if (sign != 0) {
582 StringUTF16.putChar(buf, --charPos, sign);
583 }
584 }
585
586 // Requires positive x
587 static int stringSize(long x) {
588 long p = 10;
589 for (int i=1; i<19; i++) {
590 if (x < p)
591 return i;
592 p = 10*p;
593 }
594 return 19;
595 }
596
597 /**
598 * Parses the string argument as a signed {@code long} in the
599 * radix specified by the second argument. The characters in the
600 * string must all be digits of the specified radix (as determined
601 * by whether {@link java.lang.Character#digit(char, int)} returns
602 * a nonnegative value), except that the first character may be an
603 * ASCII minus sign {@code '-'} ({@code '\u005Cu002D'}) to
604 * indicate a negative value or an ASCII plus sign {@code '+'}
605 * ({@code '\u005Cu002B'}) to indicate a positive value. The
606 * resulting {@code long} value is returned.
607 *
608 * <p>Note that neither the character {@code L}
609 * ({@code '\u005Cu004C'}) nor {@code l}
610 * ({@code '\u005Cu006C'}) is permitted to appear at the end
611 * of the string as a type indicator, as would be permitted in
612 * Java programming language source code - except that either
613 * {@code L} or {@code l} may appear as a digit for a
614 * radix greater than or equal to 22.
615 *
616 * <p>An exception of type {@code NumberFormatException} is
617 * thrown if any of the following situations occurs:
618 * <ul>
619 *
620 * <li>The first argument is {@code null} or is a string of
621 * length zero.
622 *
623 * <li>The {@code radix} is either smaller than {@link
624 * java.lang.Character#MIN_RADIX} or larger than {@link
625 * java.lang.Character#MAX_RADIX}.
626 *
627 * <li>Any character of the string is not a digit of the specified
628 * radix, except that the first character may be a minus sign
629 * {@code '-'} ({@code '\u005Cu002d'}) or plus sign {@code
630 * '+'} ({@code '\u005Cu002B'}) provided that the string is
631 * longer than length 1.
632 *
633 * <li>The value represented by the string is not a value of type
634 * {@code long}.
635 * </ul>
636 *
637 * <p>Examples:
638 * <blockquote><pre>
639 * parseLong("0", 10) returns 0L
640 * parseLong("473", 10) returns 473L
641 * parseLong("+42", 10) returns 42L
642 * parseLong("-0", 10) returns 0L
643 * parseLong("-FF", 16) returns -255L
644 * parseLong("1100110", 2) returns 102L
645 * parseLong("99", 8) throws a NumberFormatException
646 * parseLong("Hazelnut", 10) throws a NumberFormatException
647 * parseLong("Hazelnut", 36) returns 1356099454469L
648 * </pre></blockquote>
649 *
650 * @param s the {@code String} containing the
651 * {@code long} representation to be parsed.
652 * @param radix the radix to be used while parsing {@code s}.
653 * @return the {@code long} represented by the string argument in
654 * the specified radix.
655 * @throws NumberFormatException if the string does not contain a
656 * parsable {@code long}.
657 */
658 public static long parseLong(String s, int radix)
659 throws NumberFormatException
660 {
661 if (s == null) {
662 throw new NumberFormatException("null");
663 }
664
665 if (radix < Character.MIN_RADIX) {
666 throw new NumberFormatException("radix " + radix +
667 " less than Character.MIN_RADIX");
668 }
669 if (radix > Character.MAX_RADIX) {
670 throw new NumberFormatException("radix " + radix +
671 " greater than Character.MAX_RADIX");
672 }
673
674 boolean negative = false;
675 int i = 0, len = s.length();
676 long limit = -Long.MAX_VALUE;
677
678 if (len > 0) {
679 char firstChar = s.charAt(0);
680 if (firstChar < '0') { // Possible leading "+" or "-"
681 if (firstChar == '-') {
682 negative = true;
683 limit = Long.MIN_VALUE;
684 } else if (firstChar != '+') {
685 throw NumberFormatException.forInputString(s);
686 }
687
688 if (len == 1) { // Cannot have lone "+" or "-"
689 throw NumberFormatException.forInputString(s);
690 }
691 i++;
692 }
693 long multmin = limit / radix;
694 long result = 0;
695 while (i < len) {
696 // Accumulating negatively avoids surprises near MAX_VALUE
697 int digit = Character.digit(s.charAt(i++),radix);
698 if (digit < 0 || result < multmin) {
699 throw NumberFormatException.forInputString(s);
700 }
701 result *= radix;
702 if (result < limit + digit) {
703 throw NumberFormatException.forInputString(s);
704 }
705 result -= digit;
706 }
707 return negative ? result : -result;
708 } else {
709 throw NumberFormatException.forInputString(s);
710 }
711 }
712
713 /**
714 * Parses the {@link CharSequence} argument as a signed {@code long} in
715 * the specified {@code radix}, beginning at the specified
716 * {@code beginIndex} and extending to {@code endIndex - 1}.
717 *
718 * <p>The method does not take steps to guard against the
719 * {@code CharSequence} being mutated while parsing.
720 *
721 * @param s the {@code CharSequence} containing the {@code long}
722 * representation to be parsed
723 * @param beginIndex the beginning index, inclusive.
724 * @param endIndex the ending index, exclusive.
725 * @param radix the radix to be used while parsing {@code s}.
726 * @return the signed {@code long} represented by the subsequence in
727 * the specified radix.
728 * @throws NullPointerException if {@code s} is null.
729 * @throws IndexOutOfBoundsException if {@code beginIndex} is
730 * negative, or if {@code beginIndex} is greater than
731 * {@code endIndex} or if {@code endIndex} is greater than
732 * {@code s.length()}.
733 * @throws NumberFormatException if the {@code CharSequence} does not
734 * contain a parsable {@code int} in the specified
735 * {@code radix}, or if {@code radix} is either smaller than
736 * {@link java.lang.Character#MIN_RADIX} or larger than
737 * {@link java.lang.Character#MAX_RADIX}.
738 * @since 1.9
739 */
740 public static long parseLong(CharSequence s, int beginIndex, int endIndex, int radix)
741 throws NumberFormatException {
742 s = Objects.requireNonNull(s);
743
744 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
745 throw new IndexOutOfBoundsException();
746 }
747 if (radix < Character.MIN_RADIX) {
748 throw new NumberFormatException("radix " + radix +
749 " less than Character.MIN_RADIX");
750 }
751 if (radix > Character.MAX_RADIX) {
752 throw new NumberFormatException("radix " + radix +
753 " greater than Character.MAX_RADIX");
754 }
755
756 boolean negative = false;
757 int i = beginIndex;
758 long limit = -Long.MAX_VALUE;
759
760 if (i < endIndex) {
761 char firstChar = s.charAt(i);
762 if (firstChar < '0') { // Possible leading "+" or "-"
763 if (firstChar == '-') {
764 negative = true;
765 limit = Long.MIN_VALUE;
766 } else if (firstChar != '+') {
767 throw NumberFormatException.forCharSequence(s, beginIndex,
768 endIndex, i);
769 }
770 i++;
771 }
772 if (i >= endIndex) { // Cannot have lone "+", "-" or ""
773 throw NumberFormatException.forCharSequence(s, beginIndex,
774 endIndex, i);
775 }
776 long multmin = limit / radix;
777 long result = 0;
778 while (i < endIndex) {
779 // Accumulating negatively avoids surprises near MAX_VALUE
780 int digit = Character.digit(s.charAt(i), radix);
781 if (digit < 0 || result < multmin) {
782 throw NumberFormatException.forCharSequence(s, beginIndex,
783 endIndex, i);
784 }
785 result *= radix;
786 if (result < limit + digit) {
787 throw NumberFormatException.forCharSequence(s, beginIndex,
788 endIndex, i);
789 }
790 i++;
791 result -= digit;
792 }
793 return negative ? result : -result;
794 } else {
795 throw new NumberFormatException("");
796 }
797 }
798
799 /**
800 * Parses the string argument as a signed decimal {@code long}.
801 * The characters in the string must all be decimal digits, except
802 * that the first character may be an ASCII minus sign {@code '-'}
803 * ({@code \u005Cu002D'}) to indicate a negative value or an
804 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
805 * indicate a positive value. The resulting {@code long} value is
806 * returned, exactly as if the argument and the radix {@code 10}
807 * were given as arguments to the {@link
808 * #parseLong(java.lang.String, int)} method.
809 *
810 * <p>Note that neither the character {@code L}
811 * ({@code '\u005Cu004C'}) nor {@code l}
812 * ({@code '\u005Cu006C'}) is permitted to appear at the end
813 * of the string as a type indicator, as would be permitted in
814 * Java programming language source code.
815 *
816 * @param s a {@code String} containing the {@code long}
817 * representation to be parsed
818 * @return the {@code long} represented by the argument in
819 * decimal.
820 * @throws NumberFormatException if the string does not contain a
821 * parsable {@code long}.
822 */
823 public static long parseLong(String s) throws NumberFormatException {
824 return parseLong(s, 10);
825 }
826
827 /**
828 * Parses the string argument as an unsigned {@code long} in the
829 * radix specified by the second argument. An unsigned integer
830 * maps the values usually associated with negative numbers to
831 * positive numbers larger than {@code MAX_VALUE}.
832 *
833 * The characters in the string must all be digits of the
834 * specified radix (as determined by whether {@link
835 * java.lang.Character#digit(char, int)} returns a nonnegative
836 * value), except that the first character may be an ASCII plus
837 * sign {@code '+'} ({@code '\u005Cu002B'}). The resulting
838 * integer value is returned.
839 *
840 * <p>An exception of type {@code NumberFormatException} is
841 * thrown if any of the following situations occurs:
842 * <ul>
843 * <li>The first argument is {@code null} or is a string of
844 * length zero.
845 *
846 * <li>The radix is either smaller than
847 * {@link java.lang.Character#MIN_RADIX} or
848 * larger than {@link java.lang.Character#MAX_RADIX}.
849 *
850 * <li>Any character of the string is not a digit of the specified
851 * radix, except that the first character may be a plus sign
852 * {@code '+'} ({@code '\u005Cu002B'}) provided that the
853 * string is longer than length 1.
854 *
855 * <li>The value represented by the string is larger than the
856 * largest unsigned {@code long}, 2<sup>64</sup>-1.
857 *
858 * </ul>
859 *
860 *
861 * @param s the {@code String} containing the unsigned integer
862 * representation to be parsed
863 * @param radix the radix to be used while parsing {@code s}.
864 * @return the unsigned {@code long} represented by the string
865 * argument in the specified radix.
866 * @throws NumberFormatException if the {@code String}
867 * does not contain a parsable {@code long}.
868 * @since 1.8
869 */
870 public static long parseUnsignedLong(String s, int radix)
871 throws NumberFormatException {
872 if (s == null) {
873 throw new NumberFormatException("null");
874 }
875
876 int len = s.length();
877 if (len > 0) {
878 char firstChar = s.charAt(0);
879 if (firstChar == '-') {
880 throw new
881 NumberFormatException(String.format("Illegal leading minus sign " +
882 "on unsigned string %s.", s));
883 } else {
884 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
885 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
886 return parseLong(s, radix);
887 }
888
889 // No need for range checks on len due to testing above.
890 long first = parseLong(s, 0, len - 1, radix);
891 int second = Character.digit(s.charAt(len - 1), radix);
892 if (second < 0) {
893 throw new NumberFormatException("Bad digit at end of " + s);
894 }
895 long result = first * radix + second;
896
897 /*
898 * Test leftmost bits of multiprecision extension of first*radix
899 * for overflow. The number of bits needed is defined by
900 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
901 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
902 * overflow is tested by splitting guard in the ranges
903 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
904 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
905 * on a value which does not include a prime factor in the legal
906 * radix range.
907 */
908 int guard = radix * (int) (first >>> 57);
909 if (guard >= 128 ||
910 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
911 /*
912 * For purposes of exposition, the programmatic statements
913 * below should be taken to be multi-precision, i.e., not
914 * subject to overflow.
915 *
916 * A) Condition guard >= 128:
917 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
918 * hence always overflow.
919 *
920 * B) Condition guard < 92:
921 * Define left7 = first >>> 57.
922 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
923 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
924 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
925 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
926 * never overflow.
927 *
928 * C) Condition 92 <= guard < 128:
929 * first*radix + second >= radix*left7*2^57 + second
930 * so that first*radix + second >= 92*2^57 + 0 > 2^63
931 *
932 * D) Condition guard < 128:
933 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
934 * so
935 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
936 * thus
937 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
938 * whence
939 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
940 *
941 * E) Conditions C, D, and result >= 0:
942 * C and D combined imply the mathematical result
943 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
944 * bound is therefore negative as a signed long, but the
945 * upper bound is too small to overflow again after the
946 * signed long overflows to positive above 2^64 - 1. Hence
947 * result >= 0 implies overflow given C and D.
948 */
949 throw new NumberFormatException(String.format("String value %s exceeds " +
950 "range of unsigned long.", s));
951 }
952 return result;
953 }
954 } else {
955 throw NumberFormatException.forInputString(s);
956 }
957 }
958
959 /**
960 * Parses the {@link CharSequence} argument as an unsigned {@code long} in
961 * the specified {@code radix}, beginning at the specified
962 * {@code beginIndex} and extending to {@code endIndex - 1}.
963 *
964 * <p>The method does not take steps to guard against the
965 * {@code CharSequence} being mutated while parsing.
966 *
967 * @param s the {@code CharSequence} containing the unsigned
968 * {@code long} representation to be parsed
969 * @param beginIndex the beginning index, inclusive.
970 * @param endIndex the ending index, exclusive.
971 * @param radix the radix to be used while parsing {@code s}.
972 * @return the unsigned {@code long} represented by the subsequence in
973 * the specified radix.
974 * @throws NullPointerException if {@code s} is null.
975 * @throws IndexOutOfBoundsException if {@code beginIndex} is
976 * negative, or if {@code beginIndex} is greater than
977 * {@code endIndex} or if {@code endIndex} is greater than
978 * {@code s.length()}.
979 * @throws NumberFormatException if the {@code CharSequence} does not
980 * contain a parsable unsigned {@code long} in the specified
981 * {@code radix}, or if {@code radix} is either smaller than
982 * {@link java.lang.Character#MIN_RADIX} or larger than
983 * {@link java.lang.Character#MAX_RADIX}.
984 * @since 1.9
985 */
986 public static long parseUnsignedLong(CharSequence s, int beginIndex, int endIndex, int radix)
987 throws NumberFormatException {
988 s = Objects.requireNonNull(s);
989
990 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
991 throw new IndexOutOfBoundsException();
992 }
993 int start = beginIndex, len = endIndex - beginIndex;
994
995 if (len > 0) {
996 char firstChar = s.charAt(start);
997 if (firstChar == '-') {
998 throw new NumberFormatException(String.format("Illegal leading minus sign " +
999 "on unsigned string %s.", s.subSequence(start, start + len)));
1000 } else {
1001 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
1002 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
1003 return parseLong(s, start, start + len, radix);
1004 }
1005
1006 // No need for range checks on end due to testing above.
1007 long first = parseLong(s, start, start + len - 1, radix);
1008 int second = Character.digit(s.charAt(start + len - 1), radix);
1009 if (second < 0) {
1010 throw new NumberFormatException("Bad digit at end of " +
1011 s.subSequence(start, start + len));
1012 }
1013 long result = first * radix + second;
1014
1015 /*
1016 * Test leftmost bits of multiprecision extension of first*radix
1017 * for overflow. The number of bits needed is defined by
1018 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
1019 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
1020 * overflow is tested by splitting guard in the ranges
1021 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
1022 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
1023 * on a value which does not include a prime factor in the legal
1024 * radix range.
1025 */
1026 int guard = radix * (int) (first >>> 57);
1027 if (guard >= 128 ||
1028 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
1029 /*
1030 * For purposes of exposition, the programmatic statements
1031 * below should be taken to be multi-precision, i.e., not
1032 * subject to overflow.
1033 *
1034 * A) Condition guard >= 128:
1035 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
1036 * hence always overflow.
1037 *
1038 * B) Condition guard < 92:
1039 * Define left7 = first >>> 57.
1040 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
1041 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
1042 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
1043 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
1044 * never overflow.
1045 *
1046 * C) Condition 92 <= guard < 128:
1047 * first*radix + second >= radix*left7*2^57 + second
1048 * so that first*radix + second >= 92*2^57 + 0 > 2^63
1049 *
1050 * D) Condition guard < 128:
1051 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
1052 * so
1053 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
1054 * thus
1055 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
1056 * whence
1057 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
1058 *
1059 * E) Conditions C, D, and result >= 0:
1060 * C and D combined imply the mathematical result
1061 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
1062 * bound is therefore negative as a signed long, but the
1063 * upper bound is too small to overflow again after the
1064 * signed long overflows to positive above 2^64 - 1. Hence
1065 * result >= 0 implies overflow given C and D.
1066 */
1067 throw new NumberFormatException(String.format("String value %s exceeds " +
1068 "range of unsigned long.", s.subSequence(start, start + len)));
1069 }
1070 return result;
1071 }
1072 } else {
1073 throw NumberFormatException.forInputString("");
1074 }
1075 }
1076
1077 /**
1078 * Parses the string argument as an unsigned decimal {@code long}. The
1079 * characters in the string must all be decimal digits, except
1080 * that the first character may be an ASCII plus sign {@code
1081 * '+'} ({@code '\u005Cu002B'}). The resulting integer value
1082 * is returned, exactly as if the argument and the radix 10 were
1083 * given as arguments to the {@link
1084 * #parseUnsignedLong(java.lang.String, int)} method.
1085 *
1086 * @param s a {@code String} containing the unsigned {@code long}
1087 * representation to be parsed
1088 * @return the unsigned {@code long} value represented by the decimal string argument
1089 * @throws NumberFormatException if the string does not contain a
1090 * parsable unsigned integer.
1091 * @since 1.8
1092 */
1093 public static long parseUnsignedLong(String s) throws NumberFormatException {
1094 return parseUnsignedLong(s, 10);
1095 }
1096
1097 /**
1098 * Returns a {@code Long} object holding the value
1099 * extracted from the specified {@code String} when parsed
1100 * with the radix given by the second argument. The first
1101 * argument is interpreted as representing a signed
1102 * {@code long} in the radix specified by the second
1103 * argument, exactly as if the arguments were given to the {@link
1104 * #parseLong(java.lang.String, int)} method. The result is a
1105 * {@code Long} object that represents the {@code long}
1106 * value specified by the string.
1107 *
1108 * <p>In other words, this method returns a {@code Long} object equal
1109 * to the value of:
1110 *
1111 * <blockquote>
1112 * {@code new Long(Long.parseLong(s, radix))}
1113 * </blockquote>
1114 *
1115 * @param s the string to be parsed
1116 * @param radix the radix to be used in interpreting {@code s}
1117 * @return a {@code Long} object holding the value
1118 * represented by the string argument in the specified
1119 * radix.
1120 * @throws NumberFormatException If the {@code String} does not
1121 * contain a parsable {@code long}.
1122 */
1123 public static Long valueOf(String s, int radix) throws NumberFormatException {
1124 return Long.valueOf(parseLong(s, radix));
1125 }
1126
1127 /**
1128 * Returns a {@code Long} object holding the value
1129 * of the specified {@code String}. The argument is
1130 * interpreted as representing a signed decimal {@code long},
1131 * exactly as if the argument were given to the {@link
1132 * #parseLong(java.lang.String)} method. The result is a
1133 * {@code Long} object that represents the integer value
1134 * specified by the string.
1135 *
1136 * <p>In other words, this method returns a {@code Long} object
1137 * equal to the value of:
1138 *
1139 * <blockquote>
1140 * {@code new Long(Long.parseLong(s))}
1141 * </blockquote>
1142 *
1143 * @param s the string to be parsed.
1144 * @return a {@code Long} object holding the value
1145 * represented by the string argument.
1146 * @throws NumberFormatException If the string cannot be parsed
1147 * as a {@code long}.
1148 */
1149 public static Long valueOf(String s) throws NumberFormatException
1150 {
1151 return Long.valueOf(parseLong(s, 10));
1152 }
1153
1154 private static class LongCache {
1155 private LongCache(){}
1156
1157 static final Long cache[] = new Long[-(-128) + 127 + 1];
1158
1159 static {
1160 for(int i = 0; i < cache.length; i++)
1161 cache[i] = new Long(i - 128);
1162 }
1163 }
1164
1165 /**
1166 * Returns a {@code Long} instance representing the specified
1167 * {@code long} value.
1168 * If a new {@code Long} instance is not required, this method
1169 * should generally be used in preference to the constructor
1170 * {@link #Long(long)}, as this method is likely to yield
1171 * significantly better space and time performance by caching
1172 * frequently requested values.
1173 *
1174 * Note that unlike the {@linkplain Integer#valueOf(int)
1175 * corresponding method} in the {@code Integer} class, this method
1176 * is <em>not</em> required to cache values within a particular
1177 * range.
1178 *
1179 * @param l a long value.
1180 * @return a {@code Long} instance representing {@code l}.
1181 * @since 1.5
1182 */
1183 @HotSpotIntrinsicCandidate
1184 public static Long valueOf(long l) {
1185 final int offset = 128;
1186 if (l >= -128 && l <= 127) { // will cache
1187 return LongCache.cache[(int)l + offset];
1188 }
1189 return new Long(l);
1190 }
1191
1192 /**
1193 * Decodes a {@code String} into a {@code Long}.
1194 * Accepts decimal, hexadecimal, and octal numbers given by the
1195 * following grammar:
1196 *
1197 * <blockquote>
1198 * <dl>
1199 * <dt><i>DecodableString:</i>
1200 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
1201 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
1202 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
1203 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
1204 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
1205 *
1206 * <dt><i>Sign:</i>
1207 * <dd>{@code -}
1208 * <dd>{@code +}
1209 * </dl>
1210 * </blockquote>
1211 *
1212 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
1213 * are as defined in section 3.10.1 of
1214 * <cite>The Java™ Language Specification</cite>,
1215 * except that underscores are not accepted between digits.
1216 *
1217 * <p>The sequence of characters following an optional
1218 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
1219 * "{@code #}", or leading zero) is parsed as by the {@code
1220 * Long.parseLong} method with the indicated radix (10, 16, or 8).
1221 * This sequence of characters must represent a positive value or
1222 * a {@link NumberFormatException} will be thrown. The result is
1223 * negated if first character of the specified {@code String} is
1224 * the minus sign. No whitespace characters are permitted in the
1225 * {@code String}.
1226 *
1227 * @param nm the {@code String} to decode.
1228 * @return a {@code Long} object holding the {@code long}
1229 * value represented by {@code nm}
1230 * @throws NumberFormatException if the {@code String} does not
1231 * contain a parsable {@code long}.
1232 * @see java.lang.Long#parseLong(String, int)
1233 * @since 1.2
1234 */
1235 public static Long decode(String nm) throws NumberFormatException {
1236 int radix = 10;
1237 int index = 0;
1238 boolean negative = false;
1239 Long result;
1240
1241 if (nm.length() == 0)
1242 throw new NumberFormatException("Zero length string");
1243 char firstChar = nm.charAt(0);
1244 // Handle sign, if present
1245 if (firstChar == '-') {
1246 negative = true;
1247 index++;
1248 } else if (firstChar == '+')
1249 index++;
1250
1251 // Handle radix specifier, if present
1252 if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
1253 index += 2;
1254 radix = 16;
1255 }
1256 else if (nm.startsWith("#", index)) {
1257 index ++;
1258 radix = 16;
1259 }
1260 else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
1261 index ++;
1262 radix = 8;
1263 }
1264
1265 if (nm.startsWith("-", index) || nm.startsWith("+", index))
1266 throw new NumberFormatException("Sign character in wrong position");
1267
1268 try {
1269 result = Long.valueOf(nm.substring(index), radix);
1270 result = negative ? Long.valueOf(-result.longValue()) : result;
1271 } catch (NumberFormatException e) {
1272 // If number is Long.MIN_VALUE, we'll end up here. The next line
1273 // handles this case, and causes any genuine format error to be
1274 // rethrown.
1275 String constant = negative ? ("-" + nm.substring(index))
1276 : nm.substring(index);
1277 result = Long.valueOf(constant, radix);
1278 }
1279 return result;
1280 }
1281
1282 /**
1283 * The value of the {@code Long}.
1284 *
1285 * @serial
1286 */
1287 private final long value;
1288
1289 /**
1290 * Constructs a newly allocated {@code Long} object that
1291 * represents the specified {@code long} argument.
1292 *
1293 * @param value the value to be represented by the
1294 * {@code Long} object.
1295 */
1296 public Long(long value) {
1297 this.value = value;
1298 }
1299
1300 /**
1301 * Constructs a newly allocated {@code Long} object that
1302 * represents the {@code long} value indicated by the
1303 * {@code String} parameter. The string is converted to a
1304 * {@code long} value in exactly the manner used by the
1305 * {@code parseLong} method for radix 10.
1306 *
1307 * @param s the {@code String} to be converted to a
1308 * {@code Long}.
1309 * @throws NumberFormatException if the {@code String} does not
1310 * contain a parsable {@code long}.
1311 * @see java.lang.Long#parseLong(java.lang.String, int)
1312 */
1313 public Long(String s) throws NumberFormatException {
1314 this.value = parseLong(s, 10);
1315 }
1316
1317 /**
1318 * Returns the value of this {@code Long} as a {@code byte} after
1319 * a narrowing primitive conversion.
1320 * @jls 5.1.3 Narrowing Primitive Conversions
1321 */
1322 public byte byteValue() {
1323 return (byte)value;
1324 }
1325
1326 /**
1327 * Returns the value of this {@code Long} as a {@code short} after
1328 * a narrowing primitive conversion.
1329 * @jls 5.1.3 Narrowing Primitive Conversions
1330 */
1331 public short shortValue() {
1332 return (short)value;
1333 }
1334
1335 /**
1336 * Returns the value of this {@code Long} as an {@code int} after
1337 * a narrowing primitive conversion.
1338 * @jls 5.1.3 Narrowing Primitive Conversions
1339 */
1340 public int intValue() {
1341 return (int)value;
1342 }
1343
1344 /**
1345 * Returns the value of this {@code Long} as a
1346 * {@code long} value.
1347 */
1348 @HotSpotIntrinsicCandidate
1349 public long longValue() {
1350 return value;
1351 }
1352
1353 /**
1354 * Returns the value of this {@code Long} as a {@code float} after
1355 * a widening primitive conversion.
1356 * @jls 5.1.2 Widening Primitive Conversions
1357 */
1358 public float floatValue() {
1359 return (float)value;
1360 }
1361
1362 /**
1363 * Returns the value of this {@code Long} as a {@code double}
1364 * after a widening primitive conversion.
1365 * @jls 5.1.2 Widening Primitive Conversions
1366 */
1367 public double doubleValue() {
1368 return (double)value;
1369 }
1370
1371 /**
1372 * Returns a {@code String} object representing this
1373 * {@code Long}'s value. The value is converted to signed
1374 * decimal representation and returned as a string, exactly as if
1375 * the {@code long} value were given as an argument to the
1376 * {@link java.lang.Long#toString(long)} method.
1377 *
1378 * @return a string representation of the value of this object in
1379 * base 10.
1380 */
1381 public String toString() {
1382 return toString(value);
1383 }
1384
1385 /**
1386 * Returns a hash code for this {@code Long}. The result is
1387 * the exclusive OR of the two halves of the primitive
1388 * {@code long} value held by this {@code Long}
1389 * object. That is, the hashcode is the value of the expression:
1390 *
1391 * <blockquote>
1392 * {@code (int)(this.longValue()^(this.longValue()>>>32))}
1393 * </blockquote>
1394 *
1395 * @return a hash code value for this object.
1396 */
1397 @Override
1398 public int hashCode() {
1399 return Long.hashCode(value);
1400 }
1401
1402 /**
1403 * Returns a hash code for a {@code long} value; compatible with
1404 * {@code Long.hashCode()}.
1405 *
1406 * @param value the value to hash
1407 * @return a hash code value for a {@code long} value.
1408 * @since 1.8
1409 */
1410 public static int hashCode(long value) {
1411 return (int)(value ^ (value >>> 32));
1412 }
1413
1414 /**
1415 * Compares this object to the specified object. The result is
1416 * {@code true} if and only if the argument is not
1417 * {@code null} and is a {@code Long} object that
1418 * contains the same {@code long} value as this object.
1419 *
1420 * @param obj the object to compare with.
1421 * @return {@code true} if the objects are the same;
1422 * {@code false} otherwise.
1423 */
1424 public boolean equals(Object obj) {
1425 if (obj instanceof Long) {
1426 return value == ((Long)obj).longValue();
1427 }
1428 return false;
1429 }
1430
1431 /**
1432 * Determines the {@code long} value of the system property
1433 * with the specified name.
1434 *
1435 * <p>The first argument is treated as the name of a system
1436 * property. System properties are accessible through the {@link
1437 * java.lang.System#getProperty(java.lang.String)} method. The
1438 * string value of this property is then interpreted as a {@code
1439 * long} value using the grammar supported by {@link Long#decode decode}
1440 * and a {@code Long} object representing this value is returned.
1441 *
1442 * <p>If there is no property with the specified name, if the
1443 * specified name is empty or {@code null}, or if the property
1444 * does not have the correct numeric format, then {@code null} is
1445 * returned.
1446 *
1447 * <p>In other words, this method returns a {@code Long} object
1448 * equal to the value of:
1449 *
1450 * <blockquote>
1451 * {@code getLong(nm, null)}
1452 * </blockquote>
1453 *
1454 * @param nm property name.
1455 * @return the {@code Long} value of the property.
1456 * @throws SecurityException for the same reasons as
1457 * {@link System#getProperty(String) System.getProperty}
1458 * @see java.lang.System#getProperty(java.lang.String)
1459 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1460 */
1461 public static Long getLong(String nm) {
1462 return getLong(nm, null);
1463 }
1464
1465 /**
1466 * Determines the {@code long} value of the system property
1467 * with the specified name.
1468 *
1469 * <p>The first argument is treated as the name of a system
1470 * property. System properties are accessible through the {@link
1471 * java.lang.System#getProperty(java.lang.String)} method. The
1472 * string value of this property is then interpreted as a {@code
1473 * long} value using the grammar supported by {@link Long#decode decode}
1474 * and a {@code Long} object representing this value is returned.
1475 *
1476 * <p>The second argument is the default value. A {@code Long} object
1477 * that represents the value of the second argument is returned if there
1478 * is no property of the specified name, if the property does not have
1479 * the correct numeric format, or if the specified name is empty or null.
1480 *
1481 * <p>In other words, this method returns a {@code Long} object equal
1482 * to the value of:
1483 *
1484 * <blockquote>
1485 * {@code getLong(nm, new Long(val))}
1486 * </blockquote>
1487 *
1488 * but in practice it may be implemented in a manner such as:
1489 *
1490 * <blockquote><pre>
1491 * Long result = getLong(nm, null);
1492 * return (result == null) ? new Long(val) : result;
1493 * </pre></blockquote>
1494 *
1495 * to avoid the unnecessary allocation of a {@code Long} object when
1496 * the default value is not needed.
1497 *
1498 * @param nm property name.
1499 * @param val default value.
1500 * @return the {@code Long} value of the property.
1501 * @throws SecurityException for the same reasons as
1502 * {@link System#getProperty(String) System.getProperty}
1503 * @see java.lang.System#getProperty(java.lang.String)
1504 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1505 */
1506 public static Long getLong(String nm, long val) {
1507 Long result = Long.getLong(nm, null);
1508 return (result == null) ? Long.valueOf(val) : result;
1509 }
1510
1511 /**
1512 * Returns the {@code long} value of the system property with
1513 * the specified name. The first argument is treated as the name
1514 * of a system property. System properties are accessible through
1515 * the {@link java.lang.System#getProperty(java.lang.String)}
1516 * method. The string value of this property is then interpreted
1517 * as a {@code long} value, as per the
1518 * {@link Long#decode decode} method, and a {@code Long} object
1519 * representing this value is returned; in summary:
1520 *
1521 * <ul>
1522 * <li>If the property value begins with the two ASCII characters
1523 * {@code 0x} or the ASCII character {@code #}, not followed by
1524 * a minus sign, then the rest of it is parsed as a hexadecimal integer
1525 * exactly as for the method {@link #valueOf(java.lang.String, int)}
1526 * with radix 16.
1527 * <li>If the property value begins with the ASCII character
1528 * {@code 0} followed by another character, it is parsed as
1529 * an octal integer exactly as by the method {@link
1530 * #valueOf(java.lang.String, int)} with radix 8.
1531 * <li>Otherwise the property value is parsed as a decimal
1532 * integer exactly as by the method
1533 * {@link #valueOf(java.lang.String, int)} with radix 10.
1534 * </ul>
1535 *
1536 * <p>Note that, in every case, neither {@code L}
1537 * ({@code '\u005Cu004C'}) nor {@code l}
1538 * ({@code '\u005Cu006C'}) is permitted to appear at the end
1539 * of the property value as a type indicator, as would be
1540 * permitted in Java programming language source code.
1541 *
1542 * <p>The second argument is the default value. The default value is
1543 * returned if there is no property of the specified name, if the
1544 * property does not have the correct numeric format, or if the
1545 * specified name is empty or {@code null}.
1546 *
1547 * @param nm property name.
1548 * @param val default value.
1549 * @return the {@code Long} value of the property.
1550 * @throws SecurityException for the same reasons as
1551 * {@link System#getProperty(String) System.getProperty}
1552 * @see System#getProperty(java.lang.String)
1553 * @see System#getProperty(java.lang.String, java.lang.String)
1554 */
1555 public static Long getLong(String nm, Long val) {
1556 String v = null;
1557 try {
1558 v = System.getProperty(nm);
1559 } catch (IllegalArgumentException | NullPointerException e) {
1560 }
1561 if (v != null) {
1562 try {
1563 return Long.decode(v);
1564 } catch (NumberFormatException e) {
1565 }
1566 }
1567 return val;
1568 }
1569
1570 /**
1571 * Compares two {@code Long} objects numerically.
1572 *
1573 * @param anotherLong the {@code Long} to be compared.
1574 * @return the value {@code 0} if this {@code Long} is
1575 * equal to the argument {@code Long}; a value less than
1576 * {@code 0} if this {@code Long} is numerically less
1577 * than the argument {@code Long}; and a value greater
1578 * than {@code 0} if this {@code Long} is numerically
1579 * greater than the argument {@code Long} (signed
1580 * comparison).
1581 * @since 1.2
1582 */
1583 public int compareTo(Long anotherLong) {
1584 return compare(this.value, anotherLong.value);
1585 }
1586
1587 /**
1588 * Compares two {@code long} values numerically.
1589 * The value returned is identical to what would be returned by:
1590 * <pre>
1591 * Long.valueOf(x).compareTo(Long.valueOf(y))
1592 * </pre>
1593 *
1594 * @param x the first {@code long} to compare
1595 * @param y the second {@code long} to compare
1596 * @return the value {@code 0} if {@code x == y};
1597 * a value less than {@code 0} if {@code x < y}; and
1598 * a value greater than {@code 0} if {@code x > y}
1599 * @since 1.7
1600 */
1601 public static int compare(long x, long y) {
1602 return (x < y) ? -1 : ((x == y) ? 0 : 1);
1603 }
1604
1605 /**
1606 * Compares two {@code long} values numerically treating the values
1607 * as unsigned.
1608 *
1609 * @param x the first {@code long} to compare
1610 * @param y the second {@code long} to compare
1611 * @return the value {@code 0} if {@code x == y}; a value less
1612 * than {@code 0} if {@code x < y} as unsigned values; and
1613 * a value greater than {@code 0} if {@code x > y} as
1614 * unsigned values
1615 * @since 1.8
1616 */
1617 public static int compareUnsigned(long x, long y) {
1618 return compare(x + MIN_VALUE, y + MIN_VALUE);
1619 }
1620
1621
1622 /**
1623 * Returns the unsigned quotient of dividing the first argument by
1624 * the second where each argument and the result is interpreted as
1625 * an unsigned value.
1626 *
1627 * <p>Note that in two's complement arithmetic, the three other
1628 * basic arithmetic operations of add, subtract, and multiply are
1629 * bit-wise identical if the two operands are regarded as both
1630 * being signed or both being unsigned. Therefore separate {@code
1631 * addUnsigned}, etc. methods are not provided.
1632 *
1633 * @param dividend the value to be divided
1634 * @param divisor the value doing the dividing
1635 * @return the unsigned quotient of the first argument divided by
1636 * the second argument
1637 * @see #remainderUnsigned
1638 * @since 1.8
1639 */
1640 public static long divideUnsigned(long dividend, long divisor) {
1641 if (divisor < 0L) { // signed comparison
1642 // Answer must be 0 or 1 depending on relative magnitude
1643 // of dividend and divisor.
1644 return (compareUnsigned(dividend, divisor)) < 0 ? 0L :1L;
1645 }
1646
1647 if (dividend > 0) // Both inputs non-negative
1648 return dividend/divisor;
1649 else {
1650 /*
1651 * For simple code, leveraging BigInteger. Longer and faster
1652 * code written directly in terms of operations on longs is
1653 * possible; see "Hacker's Delight" for divide and remainder
1654 * algorithms.
1655 */
1656 return toUnsignedBigInteger(dividend).
1657 divide(toUnsignedBigInteger(divisor)).longValue();
1658 }
1659 }
1660
1661 /**
1662 * Returns the unsigned remainder from dividing the first argument
1663 * by the second where each argument and the result is interpreted
1664 * as an unsigned value.
1665 *
1666 * @param dividend the value to be divided
1667 * @param divisor the value doing the dividing
1668 * @return the unsigned remainder of the first argument divided by
1669 * the second argument
1670 * @see #divideUnsigned
1671 * @since 1.8
1672 */
1673 public static long remainderUnsigned(long dividend, long divisor) {
1674 if (dividend > 0 && divisor > 0) { // signed comparisons
1675 return dividend % divisor;
1676 } else {
1677 if (compareUnsigned(dividend, divisor) < 0) // Avoid explicit check for 0 divisor
1678 return dividend;
1679 else
1680 return toUnsignedBigInteger(dividend).
1681 remainder(toUnsignedBigInteger(divisor)).longValue();
1682 }
1683 }
1684
1685 // Bit Twiddling
1686
1687 /**
1688 * The number of bits used to represent a {@code long} value in two's
1689 * complement binary form.
1690 *
1691 * @since 1.5
1692 */
1693 @Native public static final int SIZE = 64;
1694
1695 /**
1696 * The number of bytes used to represent a {@code long} value in two's
1697 * complement binary form.
1698 *
1699 * @since 1.8
1700 */
1701 public static final int BYTES = SIZE / Byte.SIZE;
1702
1703 /**
1704 * Returns a {@code long} value with at most a single one-bit, in the
1705 * position of the highest-order ("leftmost") one-bit in the specified
1706 * {@code long} value. Returns zero if the specified value has no
1707 * one-bits in its two's complement binary representation, that is, if it
1708 * is equal to zero.
1709 *
1710 * @param i the value whose highest one bit is to be computed
1711 * @return a {@code long} value with a single one-bit, in the position
1712 * of the highest-order one-bit in the specified value, or zero if
1713 * the specified value is itself equal to zero.
1714 * @since 1.5
1715 */
1716 public static long highestOneBit(long i) {
1717 // HD, Figure 3-1
1718 i |= (i >> 1);
1719 i |= (i >> 2);
1720 i |= (i >> 4);
1721 i |= (i >> 8);
1722 i |= (i >> 16);
1723 i |= (i >> 32);
1724 return i - (i >>> 1);
1725 }
1726
1727 /**
1728 * Returns a {@code long} value with at most a single one-bit, in the
1729 * position of the lowest-order ("rightmost") one-bit in the specified
1730 * {@code long} value. Returns zero if the specified value has no
1731 * one-bits in its two's complement binary representation, that is, if it
1732 * is equal to zero.
1733 *
1734 * @param i the value whose lowest one bit is to be computed
1735 * @return a {@code long} value with a single one-bit, in the position
1736 * of the lowest-order one-bit in the specified value, or zero if
1737 * the specified value is itself equal to zero.
1738 * @since 1.5
1739 */
1740 public static long lowestOneBit(long i) {
1741 // HD, Section 2-1
1742 return i & -i;
1743 }
1744
1745 /**
1746 * Returns the number of zero bits preceding the highest-order
1747 * ("leftmost") one-bit in the two's complement binary representation
1748 * of the specified {@code long} value. Returns 64 if the
1749 * specified value has no one-bits in its two's complement representation,
1750 * in other words if it is equal to zero.
1751 *
1752 * <p>Note that this method is closely related to the logarithm base 2.
1753 * For all positive {@code long} values x:
1754 * <ul>
1755 * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}
1756 * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}
1757 * </ul>
1758 *
1759 * @param i the value whose number of leading zeros is to be computed
1760 * @return the number of zero bits preceding the highest-order
1761 * ("leftmost") one-bit in the two's complement binary representation
1762 * of the specified {@code long} value, or 64 if the value
1763 * is equal to zero.
1764 * @since 1.5
1765 */
1766 @HotSpotIntrinsicCandidate
1767 public static int numberOfLeadingZeros(long i) {
1768 // HD, Figure 5-6
1769 if (i == 0)
1770 return 64;
1771 int n = 1;
1772 int x = (int)(i >>> 32);
1773 if (x == 0) { n += 32; x = (int)i; }
1774 if (x >>> 16 == 0) { n += 16; x <<= 16; }
1775 if (x >>> 24 == 0) { n += 8; x <<= 8; }
1776 if (x >>> 28 == 0) { n += 4; x <<= 4; }
1777 if (x >>> 30 == 0) { n += 2; x <<= 2; }
1778 n -= x >>> 31;
1779 return n;
1780 }
1781
1782 /**
1783 * Returns the number of zero bits following the lowest-order ("rightmost")
1784 * one-bit in the two's complement binary representation of the specified
1785 * {@code long} value. Returns 64 if the specified value has no
1786 * one-bits in its two's complement representation, in other words if it is
1787 * equal to zero.
1788 *
1789 * @param i the value whose number of trailing zeros is to be computed
1790 * @return the number of zero bits following the lowest-order ("rightmost")
1791 * one-bit in the two's complement binary representation of the
1792 * specified {@code long} value, or 64 if the value is equal
1793 * to zero.
1794 * @since 1.5
1795 */
1796 @HotSpotIntrinsicCandidate
1797 public static int numberOfTrailingZeros(long i) {
1798 // HD, Figure 5-14
1799 int x, y;
1800 if (i == 0) return 64;
1801 int n = 63;
1802 y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
1803 y = x <<16; if (y != 0) { n = n -16; x = y; }
1804 y = x << 8; if (y != 0) { n = n - 8; x = y; }
1805 y = x << 4; if (y != 0) { n = n - 4; x = y; }
1806 y = x << 2; if (y != 0) { n = n - 2; x = y; }
1807 return n - ((x << 1) >>> 31);
1808 }
1809
1810 /**
1811 * Returns the number of one-bits in the two's complement binary
1812 * representation of the specified {@code long} value. This function is
1813 * sometimes referred to as the <i>population count</i>.
1814 *
1815 * @param i the value whose bits are to be counted
1816 * @return the number of one-bits in the two's complement binary
1817 * representation of the specified {@code long} value.
1818 * @since 1.5
1819 */
1820 @HotSpotIntrinsicCandidate
1821 public static int bitCount(long i) {
1822 // HD, Figure 5-2
1823 i = i - ((i >>> 1) & 0x5555555555555555L);
1824 i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
1825 i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
1826 i = i + (i >>> 8);
1827 i = i + (i >>> 16);
1828 i = i + (i >>> 32);
1829 return (int)i & 0x7f;
1830 }
1831
1832 /**
1833 * Returns the value obtained by rotating the two's complement binary
1834 * representation of the specified {@code long} value left by the
1835 * specified number of bits. (Bits shifted out of the left hand, or
1836 * high-order, side reenter on the right, or low-order.)
1837 *
1838 * <p>Note that left rotation with a negative distance is equivalent to
1839 * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
1840 * distance)}. Note also that rotation by any multiple of 64 is a
1841 * no-op, so all but the last six bits of the rotation distance can be
1842 * ignored, even if the distance is negative: {@code rotateLeft(val,
1843 * distance) == rotateLeft(val, distance & 0x3F)}.
1844 *
1845 * @param i the value whose bits are to be rotated left
1846 * @param distance the number of bit positions to rotate left
1847 * @return the value obtained by rotating the two's complement binary
1848 * representation of the specified {@code long} value left by the
1849 * specified number of bits.
1850 * @since 1.5
1851 */
1852 public static long rotateLeft(long i, int distance) {
1853 return (i << distance) | (i >>> -distance);
1854 }
1855
1856 /**
1857 * Returns the value obtained by rotating the two's complement binary
1858 * representation of the specified {@code long} value right by the
1859 * specified number of bits. (Bits shifted out of the right hand, or
1860 * low-order, side reenter on the left, or high-order.)
1861 *
1862 * <p>Note that right rotation with a negative distance is equivalent to
1863 * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
1864 * distance)}. Note also that rotation by any multiple of 64 is a
1865 * no-op, so all but the last six bits of the rotation distance can be
1866 * ignored, even if the distance is negative: {@code rotateRight(val,
1867 * distance) == rotateRight(val, distance & 0x3F)}.
1868 *
1869 * @param i the value whose bits are to be rotated right
1870 * @param distance the number of bit positions to rotate right
1871 * @return the value obtained by rotating the two's complement binary
1872 * representation of the specified {@code long} value right by the
1873 * specified number of bits.
1874 * @since 1.5
1875 */
1876 public static long rotateRight(long i, int distance) {
1877 return (i >>> distance) | (i << -distance);
1878 }
1879
1880 /**
1881 * Returns the value obtained by reversing the order of the bits in the
1882 * two's complement binary representation of the specified {@code long}
1883 * value.
1884 *
1885 * @param i the value to be reversed
1886 * @return the value obtained by reversing order of the bits in the
1887 * specified {@code long} value.
1888 * @since 1.5
1889 */
1890 public static long reverse(long i) {
1891 // HD, Figure 7-1
1892 i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
1893 i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
1894 i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
1895 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1896 i = (i << 48) | ((i & 0xffff0000L) << 16) |
1897 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1898 return i;
1899 }
1900
1901 /**
1902 * Returns the signum function of the specified {@code long} value. (The
1903 * return value is -1 if the specified value is negative; 0 if the
1904 * specified value is zero; and 1 if the specified value is positive.)
1905 *
1906 * @param i the value whose signum is to be computed
1907 * @return the signum function of the specified {@code long} value.
1908 * @since 1.5
1909 */
1910 public static int signum(long i) {
1911 // HD, Section 2-7
1912 return (int) ((i >> 63) | (-i >>> 63));
1913 }
1914
1915 /**
1916 * Returns the value obtained by reversing the order of the bytes in the
1917 * two's complement representation of the specified {@code long} value.
1918 *
1919 * @param i the value whose bytes are to be reversed
1920 * @return the value obtained by reversing the bytes in the specified
1921 * {@code long} value.
1922 * @since 1.5
1923 */
1924 @HotSpotIntrinsicCandidate
1925 public static long reverseBytes(long i) {
1926 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1927 return (i << 48) | ((i & 0xffff0000L) << 16) |
1928 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1929 }
1930
1931 /**
1932 * Adds two {@code long} values together as per the + operator.
1933 *
1934 * @param a the first operand
1935 * @param b the second operand
1936 * @return the sum of {@code a} and {@code b}
1937 * @see java.util.function.BinaryOperator
1938 * @since 1.8
1939 */
1940 public static long sum(long a, long b) {
1941 return a + b;
1942 }
1943
1944 /**
1945 * Returns the greater of two {@code long} values
1946 * as if by calling {@link Math#max(long, long) Math.max}.
1947 *
1948 * @param a the first operand
1949 * @param b the second operand
1950 * @return the greater of {@code a} and {@code b}
1951 * @see java.util.function.BinaryOperator
1952 * @since 1.8
1953 */
1954 public static long max(long a, long b) {
1955 return Math.max(a, b);
1956 }
1957
1958 /**
1959 * Returns the smaller of two {@code long} values
1960 * as if by calling {@link Math#min(long, long) Math.min}.
1961 *
1962 * @param a the first operand
1963 * @param b the second operand
1964 * @return the smaller of {@code a} and {@code b}
1965 * @see java.util.function.BinaryOperator
1966 * @since 1.8
1967 */
1968 public static long min(long a, long b) {
1969 return Math.min(a, b);
1970 }
1971
1972 /** use serialVersionUID from JDK 1.0.2 for interoperability */
1973 @Native private static final long serialVersionUID = 4290774380558885855L;
1974 }