2 * Copyright (c) 1994, 2009, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
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).
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22 * or visit www.oracle.com if you need additional information or have any
28 import org.apidesign.bck2brwsr.core.JavaScriptBody;
31 * The {@code Long} class wraps a value of the primitive type {@code
32 * long} in an object. An object of type {@code Long} contains a
33 * single field whose type is {@code long}.
35 * <p> In addition, this class provides several methods for converting
36 * a {@code long} to a {@code String} and a {@code String} to a {@code
37 * long}, as well as other constants and methods useful when dealing
38 * with a {@code long}.
40 * <p>Implementation note: The implementations of the "bit twiddling"
41 * methods (such as {@link #highestOneBit(long) highestOneBit} and
42 * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are
43 * based on material from Henry S. Warren, Jr.'s <i>Hacker's
44 * Delight</i>, (Addison Wesley, 2002).
47 * @author Arthur van Hoff
49 * @author Joseph D. Darcy
52 public final class Long extends Number implements Comparable<Long> {
54 * A constant holding the minimum value a {@code long} can
55 * have, -2<sup>63</sup>.
57 public static final long MIN_VALUE = 0x8000000000000000L;
60 * A constant holding the maximum value a {@code long} can
61 * have, 2<sup>63</sup>-1.
63 public static final long MAX_VALUE = 0x7fffffffffffffffL;
66 * The {@code Class} instance representing the primitive type
71 public static final Class<Long> TYPE = (Class<Long>) Class.getPrimitiveClass("long");
74 * Returns a string representation of the first argument in the
75 * radix specified by the second argument.
77 * <p>If the radix is smaller than {@code Character.MIN_RADIX}
78 * or larger than {@code Character.MAX_RADIX}, then the radix
79 * {@code 10} is used instead.
81 * <p>If the first argument is negative, the first element of the
82 * result is the ASCII minus sign {@code '-'}
83 * (<code>'\u002d'</code>). If the first argument is not
84 * negative, no sign character appears in the result.
86 * <p>The remaining characters of the result represent the magnitude
87 * of the first argument. If the magnitude is zero, it is
88 * represented by a single zero character {@code '0'}
89 * (<code>'\u0030'</code>); otherwise, the first character of
90 * the representation of the magnitude will not be the zero
91 * character. The following ASCII characters are used as digits:
94 * {@code 0123456789abcdefghijklmnopqrstuvwxyz}
97 * These are <code>'\u0030'</code> through
98 * <code>'\u0039'</code> and <code>'\u0061'</code> through
99 * <code>'\u007a'</code>. If {@code radix} is
100 * <var>N</var>, then the first <var>N</var> of these characters
101 * are used as radix-<var>N</var> digits in the order shown. Thus,
102 * the digits for hexadecimal (radix 16) are
103 * {@code 0123456789abcdef}. If uppercase letters are
104 * desired, the {@link java.lang.String#toUpperCase()} method may
105 * be called on the result:
108 * {@code Long.toString(n, 16).toUpperCase()}
111 * @param i a {@code long} to be converted to a string.
112 * @param radix the radix to use in the string representation.
113 * @return a string representation of the argument in the specified radix.
114 * @see java.lang.Character#MAX_RADIX
115 * @see java.lang.Character#MIN_RADIX
117 public static String toString(long i, int radix) {
118 if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
122 char[] buf = new char[65];
124 boolean negative = (i < 0);
130 while (i <= -radix) {
131 buf[charPos--] = Integer.digits[(int)(-(i % radix))];
134 buf[charPos] = Integer.digits[(int)(-i)];
137 buf[--charPos] = '-';
140 return new String(buf, charPos, (65 - charPos));
144 * Returns a string representation of the {@code long}
145 * argument as an unsigned integer in base 16.
147 * <p>The unsigned {@code long} value is the argument plus
148 * 2<sup>64</sup> if the argument is negative; otherwise, it is
149 * equal to the argument. This value is converted to a string of
150 * ASCII digits in hexadecimal (base 16) with no extra
151 * leading {@code 0}s. If the unsigned magnitude is zero, it
152 * is represented by a single zero character {@code '0'}
153 * (<code>'\u0030'</code>); otherwise, the first character of
154 * the representation of the unsigned magnitude will not be the
155 * zero character. The following characters are used as
156 * hexadecimal digits:
159 * {@code 0123456789abcdef}
162 * These are the characters <code>'\u0030'</code> through
163 * <code>'\u0039'</code> and <code>'\u0061'</code> through
164 * <code>'\u0066'</code>. If uppercase letters are desired,
165 * the {@link java.lang.String#toUpperCase()} method may be called
169 * {@code Long.toHexString(n).toUpperCase()}
172 * @param i a {@code long} to be converted to a string.
173 * @return the string representation of the unsigned {@code long}
174 * value represented by the argument in hexadecimal
178 public static String toHexString(long i) {
179 return toUnsignedString(i, 4);
183 * Returns a string representation of the {@code long}
184 * argument as an unsigned integer in base 8.
186 * <p>The unsigned {@code long} value is the argument plus
187 * 2<sup>64</sup> if the argument is negative; otherwise, it is
188 * equal to the argument. This value is converted to a string of
189 * ASCII digits in octal (base 8) with no extra leading
192 * <p>If the unsigned magnitude is zero, it is represented by a
193 * single zero character {@code '0'}
194 * (<code>'\u0030'</code>); otherwise, the first character of
195 * the representation of the unsigned magnitude will not be the
196 * zero character. The following characters are used as octal
203 * These are the characters <code>'\u0030'</code> through
204 * <code>'\u0037'</code>.
206 * @param i a {@code long} to be converted to a string.
207 * @return the string representation of the unsigned {@code long}
208 * value represented by the argument in octal (base 8).
211 public static String toOctalString(long i) {
212 return toUnsignedString(i, 3);
216 * Returns a string representation of the {@code long}
217 * argument as an unsigned integer in base 2.
219 * <p>The unsigned {@code long} value is the argument plus
220 * 2<sup>64</sup> if the argument is negative; otherwise, it is
221 * equal to the argument. This value is converted to a string of
222 * ASCII digits in binary (base 2) with no extra leading
223 * {@code 0}s. If the unsigned magnitude is zero, it is
224 * represented by a single zero character {@code '0'}
225 * (<code>'\u0030'</code>); otherwise, the first character of
226 * the representation of the unsigned magnitude will not be the
227 * zero character. The characters {@code '0'}
228 * (<code>'\u0030'</code>) and {@code '1'}
229 * (<code>'\u0031'</code>) are used as binary digits.
231 * @param i a {@code long} to be converted to a string.
232 * @return the string representation of the unsigned {@code long}
233 * value represented by the argument in binary (base 2).
236 public static String toBinaryString(long i) {
237 return toUnsignedString(i, 1);
241 * Convert the integer to an unsigned number.
243 private static String toUnsignedString(long i, int shift) {
244 char[] buf = new char[64];
246 int radix = 1 << shift;
247 long mask = radix - 1;
249 buf[--charPos] = Integer.digits[(int)(i & mask)];
252 return new String(buf, charPos, (64 - charPos));
256 * Returns a {@code String} object representing the specified
257 * {@code long}. The argument is converted to signed decimal
258 * representation and returned as a string, exactly as if the
259 * argument and the radix 10 were given as arguments to the {@link
260 * #toString(long, int)} method.
262 * @param i a {@code long} to be converted.
263 * @return a string representation of the argument in base 10.
265 @JavaScriptBody(args = "i", body = "return i.toString();")
266 public static String toString(long i) {
267 if (i == Long.MIN_VALUE)
268 return "-9223372036854775808";
269 int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
270 char[] buf = new char[size];
271 getChars(i, size, buf);
272 return new String(buf, 0, size);
276 * Places characters representing the integer i into the
277 * character array buf. The characters are placed into
278 * the buffer backwards starting with the least significant
279 * digit at the specified index (exclusive), and working
280 * backwards from there.
282 * Will fail if i == Long.MIN_VALUE
284 static void getChars(long i, int index, char[] buf) {
295 // Get 2 digits/iteration using longs until quotient fits into an int
296 while (i > Integer.MAX_VALUE) {
298 // really: r = i - (q * 100);
299 r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
301 buf[--charPos] = Integer.DigitOnes[r];
302 buf[--charPos] = Integer.DigitTens[r];
305 // Get 2 digits/iteration using ints
308 while (i2 >= 65536) {
310 // really: r = i2 - (q * 100);
311 r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
313 buf[--charPos] = Integer.DigitOnes[r];
314 buf[--charPos] = Integer.DigitTens[r];
317 // Fall thru to fast mode for smaller numbers
318 // assert(i2 <= 65536, i2);
320 q2 = (i2 * 52429) >>> (16+3);
321 r = i2 - ((q2 << 3) + (q2 << 1)); // r = i2-(q2*10) ...
322 buf[--charPos] = Integer.digits[r];
327 buf[--charPos] = sign;
331 // Requires positive x
332 static int stringSize(long x) {
334 for (int i=1; i<19; i++) {
343 * Parses the string argument as a signed {@code long} in the
344 * radix specified by the second argument. The characters in the
345 * string must all be digits of the specified radix (as determined
346 * by whether {@link java.lang.Character#digit(char, int)} returns
347 * a nonnegative value), except that the first character may be an
348 * ASCII minus sign {@code '-'} (<code>'\u002D'</code>) to
349 * indicate a negative value or an ASCII plus sign {@code '+'}
350 * (<code>'\u002B'</code>) to indicate a positive value. The
351 * resulting {@code long} value is returned.
353 * <p>Note that neither the character {@code L}
354 * (<code>'\u004C'</code>) nor {@code l}
355 * (<code>'\u006C'</code>) is permitted to appear at the end
356 * of the string as a type indicator, as would be permitted in
357 * Java programming language source code - except that either
358 * {@code L} or {@code l} may appear as a digit for a
359 * radix greater than 22.
361 * <p>An exception of type {@code NumberFormatException} is
362 * thrown if any of the following situations occurs:
365 * <li>The first argument is {@code null} or is a string of
368 * <li>The {@code radix} is either smaller than {@link
369 * java.lang.Character#MIN_RADIX} or larger than {@link
370 * java.lang.Character#MAX_RADIX}.
372 * <li>Any character of the string is not a digit of the specified
373 * radix, except that the first character may be a minus sign
374 * {@code '-'} (<code>'\u002d'</code>) or plus sign {@code
375 * '+'} (<code>'\u002B'</code>) provided that the string is
376 * longer than length 1.
378 * <li>The value represented by the string is not a value of type
384 * parseLong("0", 10) returns 0L
385 * parseLong("473", 10) returns 473L
386 * parseLong("+42", 10) returns 42L
387 * parseLong("-0", 10) returns 0L
388 * parseLong("-FF", 16) returns -255L
389 * parseLong("1100110", 2) returns 102L
390 * parseLong("99", 8) throws a NumberFormatException
391 * parseLong("Hazelnut", 10) throws a NumberFormatException
392 * parseLong("Hazelnut", 36) returns 1356099454469L
393 * </pre></blockquote>
395 * @param s the {@code String} containing the
396 * {@code long} representation to be parsed.
397 * @param radix the radix to be used while parsing {@code s}.
398 * @return the {@code long} represented by the string argument in
399 * the specified radix.
400 * @throws NumberFormatException if the string does not contain a
401 * parsable {@code long}.
403 public static long parseLong(String s, int radix)
404 throws NumberFormatException
407 throw new NumberFormatException("null");
410 if (radix < Character.MIN_RADIX) {
411 throw new NumberFormatException("radix " + radix +
412 " less than Character.MIN_RADIX");
414 if (radix > Character.MAX_RADIX) {
415 throw new NumberFormatException("radix " + radix +
416 " greater than Character.MAX_RADIX");
420 boolean negative = false;
421 int i = 0, len = s.length();
422 long limit = -Long.MAX_VALUE;
427 char firstChar = s.charAt(0);
428 if (firstChar < '0') { // Possible leading "+" or "-"
429 if (firstChar == '-') {
431 limit = Long.MIN_VALUE;
432 } else if (firstChar != '+')
433 throw NumberFormatException.forInputString(s);
435 if (len == 1) // Cannot have lone "+" or "-"
436 throw NumberFormatException.forInputString(s);
439 multmin = limit / radix;
441 // Accumulating negatively avoids surprises near MAX_VALUE
442 digit = Character.digit(s.charAt(i++),radix);
444 throw NumberFormatException.forInputString(s);
446 if (result < multmin) {
447 throw NumberFormatException.forInputString(s);
450 if (result < limit + digit) {
451 throw NumberFormatException.forInputString(s);
456 throw NumberFormatException.forInputString(s);
458 return negative ? result : -result;
462 * Parses the string argument as a signed decimal {@code long}.
463 * The characters in the string must all be decimal digits, except
464 * that the first character may be an ASCII minus sign {@code '-'}
465 * (<code>\u002D'</code>) to indicate a negative value or an
466 * ASCII plus sign {@code '+'} (<code>'\u002B'</code>) to
467 * indicate a positive value. The resulting {@code long} value is
468 * returned, exactly as if the argument and the radix {@code 10}
469 * were given as arguments to the {@link
470 * #parseLong(java.lang.String, int)} method.
472 * <p>Note that neither the character {@code L}
473 * (<code>'\u004C'</code>) nor {@code l}
474 * (<code>'\u006C'</code>) is permitted to appear at the end
475 * of the string as a type indicator, as would be permitted in
476 * Java programming language source code.
478 * @param s a {@code String} containing the {@code long}
479 * representation to be parsed
480 * @return the {@code long} represented by the argument in
482 * @throws NumberFormatException if the string does not contain a
483 * parsable {@code long}.
485 public static long parseLong(String s) throws NumberFormatException {
486 return parseLong(s, 10);
490 * Returns a {@code Long} object holding the value
491 * extracted from the specified {@code String} when parsed
492 * with the radix given by the second argument. The first
493 * argument is interpreted as representing a signed
494 * {@code long} in the radix specified by the second
495 * argument, exactly as if the arguments were given to the {@link
496 * #parseLong(java.lang.String, int)} method. The result is a
497 * {@code Long} object that represents the {@code long}
498 * value specified by the string.
500 * <p>In other words, this method returns a {@code Long} object equal
504 * {@code new Long(Long.parseLong(s, radix))}
507 * @param s the string to be parsed
508 * @param radix the radix to be used in interpreting {@code s}
509 * @return a {@code Long} object holding the value
510 * represented by the string argument in the specified
512 * @throws NumberFormatException If the {@code String} does not
513 * contain a parsable {@code long}.
515 public static Long valueOf(String s, int radix) throws NumberFormatException {
516 return Long.valueOf(parseLong(s, radix));
520 * Returns a {@code Long} object holding the value
521 * of the specified {@code String}. The argument is
522 * interpreted as representing a signed decimal {@code long},
523 * exactly as if the argument were given to the {@link
524 * #parseLong(java.lang.String)} method. The result is a
525 * {@code Long} object that represents the integer value
526 * specified by the string.
528 * <p>In other words, this method returns a {@code Long} object
529 * equal to the value of:
532 * {@code new Long(Long.parseLong(s))}
535 * @param s the string to be parsed.
536 * @return a {@code Long} object holding the value
537 * represented by the string argument.
538 * @throws NumberFormatException If the string cannot be parsed
541 public static Long valueOf(String s) throws NumberFormatException
543 return Long.valueOf(parseLong(s, 10));
546 private static class LongCache {
547 private LongCache(){}
549 static final Long cache[] = new Long[-(-128) + 127 + 1];
552 for(int i = 0; i < cache.length; i++)
553 cache[i] = new Long(i - 128);
558 * Returns a {@code Long} instance representing the specified
559 * {@code long} value.
560 * If a new {@code Long} instance is not required, this method
561 * should generally be used in preference to the constructor
562 * {@link #Long(long)}, as this method is likely to yield
563 * significantly better space and time performance by caching
564 * frequently requested values.
566 * Note that unlike the {@linkplain Integer#valueOf(int)
567 * corresponding method} in the {@code Integer} class, this method
568 * is <em>not</em> required to cache values within a particular
571 * @param l a long value.
572 * @return a {@code Long} instance representing {@code l}.
575 public static Long valueOf(long l) {
576 final int offset = 128;
577 if (l >= -128 && l <= 127) { // will cache
578 return LongCache.cache[(int)l + offset];
584 * Decodes a {@code String} into a {@code Long}.
585 * Accepts decimal, hexadecimal, and octal numbers given by the
590 * <dt><i>DecodableString:</i>
591 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
592 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
593 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
594 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
595 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
603 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
604 * are as defined in section 3.10.1 of
605 * <cite>The Java™ Language Specification</cite>,
606 * except that underscores are not accepted between digits.
608 * <p>The sequence of characters following an optional
609 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
610 * "{@code #}", or leading zero) is parsed as by the {@code
611 * Long.parseLong} method with the indicated radix (10, 16, or 8).
612 * This sequence of characters must represent a positive value or
613 * a {@link NumberFormatException} will be thrown. The result is
614 * negated if first character of the specified {@code String} is
615 * the minus sign. No whitespace characters are permitted in the
618 * @param nm the {@code String} to decode.
619 * @return a {@code Long} object holding the {@code long}
620 * value represented by {@code nm}
621 * @throws NumberFormatException if the {@code String} does not
622 * contain a parsable {@code long}.
623 * @see java.lang.Long#parseLong(String, int)
626 public static Long decode(String nm) throws NumberFormatException {
629 boolean negative = false;
632 if (nm.length() == 0)
633 throw new NumberFormatException("Zero length string");
634 char firstChar = nm.charAt(0);
635 // Handle sign, if present
636 if (firstChar == '-') {
639 } else if (firstChar == '+')
642 // Handle radix specifier, if present
643 if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
647 else if (nm.startsWith("#", index)) {
651 else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
656 if (nm.startsWith("-", index) || nm.startsWith("+", index))
657 throw new NumberFormatException("Sign character in wrong position");
660 result = Long.valueOf(nm.substring(index), radix);
661 result = negative ? Long.valueOf(-result.longValue()) : result;
662 } catch (NumberFormatException e) {
663 // If number is Long.MIN_VALUE, we'll end up here. The next line
664 // handles this case, and causes any genuine format error to be
666 String constant = negative ? ("-" + nm.substring(index))
667 : nm.substring(index);
668 result = Long.valueOf(constant, radix);
674 * The value of the {@code Long}.
678 private final long value;
681 * Constructs a newly allocated {@code Long} object that
682 * represents the specified {@code long} argument.
684 * @param value the value to be represented by the
685 * {@code Long} object.
687 public Long(long value) {
692 * Constructs a newly allocated {@code Long} object that
693 * represents the {@code long} value indicated by the
694 * {@code String} parameter. The string is converted to a
695 * {@code long} value in exactly the manner used by the
696 * {@code parseLong} method for radix 10.
698 * @param s the {@code String} to be converted to a
700 * @throws NumberFormatException if the {@code String} does not
701 * contain a parsable {@code long}.
702 * @see java.lang.Long#parseLong(java.lang.String, int)
704 public Long(String s) throws NumberFormatException {
705 this.value = parseLong(s, 10);
709 * Returns the value of this {@code Long} as a
712 public byte byteValue() {
717 * Returns the value of this {@code Long} as a
720 public short shortValue() {
725 * Returns the value of this {@code Long} as an
728 public int intValue() {
733 * Returns the value of this {@code Long} as a
734 * {@code long} value.
736 public long longValue() {
741 * Returns the value of this {@code Long} as a
744 public float floatValue() {
749 * Returns the value of this {@code Long} as a
752 public double doubleValue() {
753 return (double)value;
757 * Returns a {@code String} object representing this
758 * {@code Long}'s value. The value is converted to signed
759 * decimal representation and returned as a string, exactly as if
760 * the {@code long} value were given as an argument to the
761 * {@link java.lang.Long#toString(long)} method.
763 * @return a string representation of the value of this object in
766 public String toString() {
767 return toString(value);
771 * Returns a hash code for this {@code Long}. The result is
772 * the exclusive OR of the two halves of the primitive
773 * {@code long} value held by this {@code Long}
774 * object. That is, the hashcode is the value of the expression:
777 * {@code (int)(this.longValue()^(this.longValue()>>>32))}
780 * @return a hash code value for this object.
782 public int hashCode() {
783 return (int)(value ^ (value >>> 32));
787 * Compares this object to the specified object. The result is
788 * {@code true} if and only if the argument is not
789 * {@code null} and is a {@code Long} object that
790 * contains the same {@code long} value as this object.
792 * @param obj the object to compare with.
793 * @return {@code true} if the objects are the same;
794 * {@code false} otherwise.
796 public boolean equals(Object obj) {
797 if (obj instanceof Long) {
798 return value == ((Long)obj).longValue();
804 * Determines the {@code long} value of the system property
805 * with the specified name.
807 * <p>The first argument is treated as the name of a system property.
808 * System properties are accessible through the {@link
809 * java.lang.System#getProperty(java.lang.String)} method. The
810 * string value of this property is then interpreted as a
811 * {@code long} value and a {@code Long} object
812 * representing this value is returned. Details of possible
813 * numeric formats can be found with the definition of
814 * {@code getProperty}.
816 * <p>If there is no property with the specified name, if the
817 * specified name is empty or {@code null}, or if the
818 * property does not have the correct numeric format, then
819 * {@code null} is returned.
821 * <p>In other words, this method returns a {@code Long} object equal to
825 * {@code getLong(nm, null)}
828 * @param nm property name.
829 * @return the {@code Long} value of the property.
830 * @see java.lang.System#getProperty(java.lang.String)
831 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
833 public static Long getLong(String nm) {
834 return getLong(nm, null);
838 * Determines the {@code long} value of the system property
839 * with the specified name.
841 * <p>The first argument is treated as the name of a system property.
842 * System properties are accessible through the {@link
843 * java.lang.System#getProperty(java.lang.String)} method. The
844 * string value of this property is then interpreted as a
845 * {@code long} value and a {@code Long} object
846 * representing this value is returned. Details of possible
847 * numeric formats can be found with the definition of
848 * {@code getProperty}.
850 * <p>The second argument is the default value. A {@code Long} object
851 * that represents the value of the second argument is returned if there
852 * is no property of the specified name, if the property does not have
853 * the correct numeric format, or if the specified name is empty or null.
855 * <p>In other words, this method returns a {@code Long} object equal
859 * {@code getLong(nm, new Long(val))}
862 * but in practice it may be implemented in a manner such as:
865 * Long result = getLong(nm, null);
866 * return (result == null) ? new Long(val) : result;
867 * </pre></blockquote>
869 * to avoid the unnecessary allocation of a {@code Long} object when
870 * the default value is not needed.
872 * @param nm property name.
873 * @param val default value.
874 * @return the {@code Long} value of the property.
875 * @see java.lang.System#getProperty(java.lang.String)
876 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
878 public static Long getLong(String nm, long val) {
879 Long result = Long.getLong(nm, null);
880 return (result == null) ? Long.valueOf(val) : result;
884 * Returns the {@code long} value of the system property with
885 * the specified name. The first argument is treated as the name
886 * of a system property. System properties are accessible through
887 * the {@link java.lang.System#getProperty(java.lang.String)}
888 * method. The string value of this property is then interpreted
889 * as a {@code long} value, as per the
890 * {@code Long.decode} method, and a {@code Long} object
891 * representing this value is returned.
894 * <li>If the property value begins with the two ASCII characters
895 * {@code 0x} or the ASCII character {@code #}, not followed by
896 * a minus sign, then the rest of it is parsed as a hexadecimal integer
897 * exactly as for the method {@link #valueOf(java.lang.String, int)}
899 * <li>If the property value begins with the ASCII character
900 * {@code 0} followed by another character, it is parsed as
901 * an octal integer exactly as by the method {@link
902 * #valueOf(java.lang.String, int)} with radix 8.
903 * <li>Otherwise the property value is parsed as a decimal
904 * integer exactly as by the method
905 * {@link #valueOf(java.lang.String, int)} with radix 10.
908 * <p>Note that, in every case, neither {@code L}
909 * (<code>'\u004C'</code>) nor {@code l}
910 * (<code>'\u006C'</code>) is permitted to appear at the end
911 * of the property value as a type indicator, as would be
912 * permitted in Java programming language source code.
914 * <p>The second argument is the default value. The default value is
915 * returned if there is no property of the specified name, if the
916 * property does not have the correct numeric format, or if the
917 * specified name is empty or {@code null}.
919 * @param nm property name.
920 * @param val default value.
921 * @return the {@code Long} value of the property.
922 * @see java.lang.System#getProperty(java.lang.String)
923 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
924 * @see java.lang.Long#decode
926 public static Long getLong(String nm, Long val) {
929 v = AbstractStringBuilder.getProperty(nm);
930 } catch (IllegalArgumentException e) {
931 } catch (NullPointerException e) {
935 return Long.decode(v);
936 } catch (NumberFormatException e) {
943 * Compares two {@code Long} objects numerically.
945 * @param anotherLong the {@code Long} to be compared.
946 * @return the value {@code 0} if this {@code Long} is
947 * equal to the argument {@code Long}; a value less than
948 * {@code 0} if this {@code Long} is numerically less
949 * than the argument {@code Long}; and a value greater
950 * than {@code 0} if this {@code Long} is numerically
951 * greater than the argument {@code Long} (signed
955 public int compareTo(Long anotherLong) {
956 return compare(this.value, anotherLong.value);
960 * Compares two {@code long} values numerically.
961 * The value returned is identical to what would be returned by:
963 * Long.valueOf(x).compareTo(Long.valueOf(y))
966 * @param x the first {@code long} to compare
967 * @param y the second {@code long} to compare
968 * @return the value {@code 0} if {@code x == y};
969 * a value less than {@code 0} if {@code x < y}; and
970 * a value greater than {@code 0} if {@code x > y}
973 public static int compare(long x, long y) {
974 return (x < y) ? -1 : ((x == y) ? 0 : 1);
981 * The number of bits used to represent a {@code long} value in two's
982 * complement binary form.
986 public static final int SIZE = 64;
989 * Returns a {@code long} value with at most a single one-bit, in the
990 * position of the highest-order ("leftmost") one-bit in the specified
991 * {@code long} value. Returns zero if the specified value has no
992 * one-bits in its two's complement binary representation, that is, if it
995 * @return a {@code long} value with a single one-bit, in the position
996 * of the highest-order one-bit in the specified value, or zero if
997 * the specified value is itself equal to zero.
1000 public static long highestOneBit(long i) {
1008 return i - (i >>> 1);
1012 * Returns a {@code long} value with at most a single one-bit, in the
1013 * position of the lowest-order ("rightmost") one-bit in the specified
1014 * {@code long} value. Returns zero if the specified value has no
1015 * one-bits in its two's complement binary representation, that is, if it
1018 * @return a {@code long} value with a single one-bit, in the position
1019 * of the lowest-order one-bit in the specified value, or zero if
1020 * the specified value is itself equal to zero.
1023 public static long lowestOneBit(long i) {
1029 * Returns the number of zero bits preceding the highest-order
1030 * ("leftmost") one-bit in the two's complement binary representation
1031 * of the specified {@code long} value. Returns 64 if the
1032 * specified value has no one-bits in its two's complement representation,
1033 * in other words if it is equal to zero.
1035 * <p>Note that this method is closely related to the logarithm base 2.
1036 * For all positive {@code long} values x:
1038 * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}
1039 * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}
1042 * @return the number of zero bits preceding the highest-order
1043 * ("leftmost") one-bit in the two's complement binary representation
1044 * of the specified {@code long} value, or 64 if the value
1048 public static int numberOfLeadingZeros(long i) {
1053 int x = (int)(i >>> 32);
1054 if (x == 0) { n += 32; x = (int)i; }
1055 if (x >>> 16 == 0) { n += 16; x <<= 16; }
1056 if (x >>> 24 == 0) { n += 8; x <<= 8; }
1057 if (x >>> 28 == 0) { n += 4; x <<= 4; }
1058 if (x >>> 30 == 0) { n += 2; x <<= 2; }
1064 * Returns the number of zero bits following the lowest-order ("rightmost")
1065 * one-bit in the two's complement binary representation of the specified
1066 * {@code long} value. Returns 64 if the specified value has no
1067 * one-bits in its two's complement representation, in other words if it is
1070 * @return the number of zero bits following the lowest-order ("rightmost")
1071 * one-bit in the two's complement binary representation of the
1072 * specified {@code long} value, or 64 if the value is equal
1076 public static int numberOfTrailingZeros(long i) {
1079 if (i == 0) return 64;
1081 y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
1082 y = x <<16; if (y != 0) { n = n -16; x = y; }
1083 y = x << 8; if (y != 0) { n = n - 8; x = y; }
1084 y = x << 4; if (y != 0) { n = n - 4; x = y; }
1085 y = x << 2; if (y != 0) { n = n - 2; x = y; }
1086 return n - ((x << 1) >>> 31);
1090 * Returns the number of one-bits in the two's complement binary
1091 * representation of the specified {@code long} value. This function is
1092 * sometimes referred to as the <i>population count</i>.
1094 * @return the number of one-bits in the two's complement binary
1095 * representation of the specified {@code long} value.
1098 public static int bitCount(long i) {
1100 i = i - ((i >>> 1) & 0x5555555555555555L);
1101 i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
1102 i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
1106 return (int)i & 0x7f;
1110 * Returns the value obtained by rotating the two's complement binary
1111 * representation of the specified {@code long} value left by the
1112 * specified number of bits. (Bits shifted out of the left hand, or
1113 * high-order, side reenter on the right, or low-order.)
1115 * <p>Note that left rotation with a negative distance is equivalent to
1116 * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
1117 * distance)}. Note also that rotation by any multiple of 64 is a
1118 * no-op, so all but the last six bits of the rotation distance can be
1119 * ignored, even if the distance is negative: {@code rotateLeft(val,
1120 * distance) == rotateLeft(val, distance & 0x3F)}.
1122 * @return the value obtained by rotating the two's complement binary
1123 * representation of the specified {@code long} value left by the
1124 * specified number of bits.
1127 public static long rotateLeft(long i, int distance) {
1128 return (i << distance) | (i >>> -distance);
1132 * Returns the value obtained by rotating the two's complement binary
1133 * representation of the specified {@code long} value right by the
1134 * specified number of bits. (Bits shifted out of the right hand, or
1135 * low-order, side reenter on the left, or high-order.)
1137 * <p>Note that right rotation with a negative distance is equivalent to
1138 * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
1139 * distance)}. Note also that rotation by any multiple of 64 is a
1140 * no-op, so all but the last six bits of the rotation distance can be
1141 * ignored, even if the distance is negative: {@code rotateRight(val,
1142 * distance) == rotateRight(val, distance & 0x3F)}.
1144 * @return the value obtained by rotating the two's complement binary
1145 * representation of the specified {@code long} value right by the
1146 * specified number of bits.
1149 public static long rotateRight(long i, int distance) {
1150 return (i >>> distance) | (i << -distance);
1154 * Returns the value obtained by reversing the order of the bits in the
1155 * two's complement binary representation of the specified {@code long}
1158 * @return the value obtained by reversing order of the bits in the
1159 * specified {@code long} value.
1162 public static long reverse(long i) {
1164 i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
1165 i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
1166 i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
1167 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1168 i = (i << 48) | ((i & 0xffff0000L) << 16) |
1169 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1174 * Returns the signum function of the specified {@code long} value. (The
1175 * return value is -1 if the specified value is negative; 0 if the
1176 * specified value is zero; and 1 if the specified value is positive.)
1178 * @return the signum function of the specified {@code long} value.
1181 public static int signum(long i) {
1183 return (int) ((i >> 63) | (-i >>> 63));
1187 * Returns the value obtained by reversing the order of the bytes in the
1188 * two's complement representation of the specified {@code long} value.
1190 * @return the value obtained by reversing the bytes in the specified
1191 * {@code long} value.
1194 public static long reverseBytes(long i) {
1195 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1196 return (i << 48) | ((i & 0xffff0000L) << 16) |
1197 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1200 /** use serialVersionUID from JDK 1.0.2 for interoperability */
1201 private static final long serialVersionUID = 4290774380558885855L;