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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

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1+/*
2+ * Copyright (c) 1994, 2010, 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 sun.misc.FloatingDecimal;
29+import sun.misc.FpUtils;
30+import sun.misc.DoubleConsts;
31+
32+/**
33+ * The {@code Double} class wraps a value of the primitive type
34+ * {@code double} in an object. An object of type
35+ * {@code Double} contains a single field whose type is
36+ * {@code double}.
37+ *
38+ * <p>In addition, this class provides several methods for converting a
39+ * {@code double} to a {@code String} and a
40+ * {@code String} to a {@code double}, as well as other
41+ * constants and methods useful when dealing with a
42+ * {@code double}.
43+ *
44+ * @author Lee Boynton
45+ * @author Arthur van Hoff
46+ * @author Joseph D. Darcy
47+ * @since JDK1.0
48+ */
49+public final class Double extends Number implements Comparable<Double> {
50+ /**
51+ * A constant holding the positive infinity of type
52+ * {@code double}. It is equal to the value returned by
53+ * {@code Double.longBitsToDouble(0x7ff0000000000000L)}.
54+ */
55+ public static final double POSITIVE_INFINITY = 1.0 / 0.0;
56+
57+ /**
58+ * A constant holding the negative infinity of type
59+ * {@code double}. It is equal to the value returned by
60+ * {@code Double.longBitsToDouble(0xfff0000000000000L)}.
61+ */
62+ public static final double NEGATIVE_INFINITY = -1.0 / 0.0;
63+
64+ /**
65+ * A constant holding a Not-a-Number (NaN) value of type
66+ * {@code double}. It is equivalent to the value returned by
67+ * {@code Double.longBitsToDouble(0x7ff8000000000000L)}.
68+ */
69+ public static final double NaN = 0.0d / 0.0;
70+
71+ /**
72+ * A constant holding the largest positive finite value of type
73+ * {@code double},
74+ * (2-2<sup>-52</sup>)&middot;2<sup>1023</sup>. It is equal to
75+ * the hexadecimal floating-point literal
76+ * {@code 0x1.fffffffffffffP+1023} and also equal to
77+ * {@code Double.longBitsToDouble(0x7fefffffffffffffL)}.
78+ */
79+ public static final double MAX_VALUE = 0x1.fffffffffffffP+1023; // 1.7976931348623157e+308
80+
81+ /**
82+ * A constant holding the smallest positive normal value of type
83+ * {@code double}, 2<sup>-1022</sup>. It is equal to the
84+ * hexadecimal floating-point literal {@code 0x1.0p-1022} and also
85+ * equal to {@code Double.longBitsToDouble(0x0010000000000000L)}.
86+ *
87+ * @since 1.6
88+ */
89+ public static final double MIN_NORMAL = 0x1.0p-1022; // 2.2250738585072014E-308
90+
91+ /**
92+ * A constant holding the smallest positive nonzero value of type
93+ * {@code double}, 2<sup>-1074</sup>. It is equal to the
94+ * hexadecimal floating-point literal
95+ * {@code 0x0.0000000000001P-1022} and also equal to
96+ * {@code Double.longBitsToDouble(0x1L)}.
97+ */
98+ public static final double MIN_VALUE = 0x0.0000000000001P-1022; // 4.9e-324
99+
100+ /**
101+ * Maximum exponent a finite {@code double} variable may have.
102+ * It is equal to the value returned by
103+ * {@code Math.getExponent(Double.MAX_VALUE)}.
104+ *
105+ * @since 1.6
106+ */
107+ public static final int MAX_EXPONENT = 1023;
108+
109+ /**
110+ * Minimum exponent a normalized {@code double} variable may
111+ * have. It is equal to the value returned by
112+ * {@code Math.getExponent(Double.MIN_NORMAL)}.
113+ *
114+ * @since 1.6
115+ */
116+ public static final int MIN_EXPONENT = -1022;
117+
118+ /**
119+ * The number of bits used to represent a {@code double} value.
120+ *
121+ * @since 1.5
122+ */
123+ public static final int SIZE = 64;
124+
125+ /**
126+ * The {@code Class} instance representing the primitive type
127+ * {@code double}.
128+ *
129+ * @since JDK1.1
130+ */
131+ public static final Class<Double> TYPE = (Class<Double>) Class.getPrimitiveClass("double");
132+
133+ /**
134+ * Returns a string representation of the {@code double}
135+ * argument. All characters mentioned below are ASCII characters.
136+ * <ul>
137+ * <li>If the argument is NaN, the result is the string
138+ * "{@code NaN}".
139+ * <li>Otherwise, the result is a string that represents the sign and
140+ * magnitude (absolute value) of the argument. If the sign is negative,
141+ * the first character of the result is '{@code -}'
142+ * (<code>'&#92;u002D'</code>); if the sign is positive, no sign character
143+ * appears in the result. As for the magnitude <i>m</i>:
144+ * <ul>
145+ * <li>If <i>m</i> is infinity, it is represented by the characters
146+ * {@code "Infinity"}; thus, positive infinity produces the result
147+ * {@code "Infinity"} and negative infinity produces the result
148+ * {@code "-Infinity"}.
149+ *
150+ * <li>If <i>m</i> is zero, it is represented by the characters
151+ * {@code "0.0"}; thus, negative zero produces the result
152+ * {@code "-0.0"} and positive zero produces the result
153+ * {@code "0.0"}.
154+ *
155+ * <li>If <i>m</i> is greater than or equal to 10<sup>-3</sup> but less
156+ * than 10<sup>7</sup>, then it is represented as the integer part of
157+ * <i>m</i>, in decimal form with no leading zeroes, followed by
158+ * '{@code .}' (<code>'&#92;u002E'</code>), followed by one or
159+ * more decimal digits representing the fractional part of <i>m</i>.
160+ *
161+ * <li>If <i>m</i> is less than 10<sup>-3</sup> or greater than or
162+ * equal to 10<sup>7</sup>, then it is represented in so-called
163+ * "computerized scientific notation." Let <i>n</i> be the unique
164+ * integer such that 10<sup><i>n</i></sup> &le; <i>m</i> {@literal <}
165+ * 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the
166+ * mathematically exact quotient of <i>m</i> and
167+ * 10<sup><i>n</i></sup> so that 1 &le; <i>a</i> {@literal <} 10. The
168+ * magnitude is then represented as the integer part of <i>a</i>,
169+ * as a single decimal digit, followed by '{@code .}'
170+ * (<code>'&#92;u002E'</code>), followed by decimal digits
171+ * representing the fractional part of <i>a</i>, followed by the
172+ * letter '{@code E}' (<code>'&#92;u0045'</code>), followed
173+ * by a representation of <i>n</i> as a decimal integer, as
174+ * produced by the method {@link Integer#toString(int)}.
175+ * </ul>
176+ * </ul>
177+ * How many digits must be printed for the fractional part of
178+ * <i>m</i> or <i>a</i>? There must be at least one digit to represent
179+ * the fractional part, and beyond that as many, but only as many, more
180+ * digits as are needed to uniquely distinguish the argument value from
181+ * adjacent values of type {@code double}. That is, suppose that
182+ * <i>x</i> is the exact mathematical value represented by the decimal
183+ * representation produced by this method for a finite nonzero argument
184+ * <i>d</i>. Then <i>d</i> must be the {@code double} value nearest
185+ * to <i>x</i>; or if two {@code double} values are equally close
186+ * to <i>x</i>, then <i>d</i> must be one of them and the least
187+ * significant bit of the significand of <i>d</i> must be {@code 0}.
188+ *
189+ * <p>To create localized string representations of a floating-point
190+ * value, use subclasses of {@link java.text.NumberFormat}.
191+ *
192+ * @param d the {@code double} to be converted.
193+ * @return a string representation of the argument.
194+ */
195+ public static String toString(double d) {
196+ return new FloatingDecimal(d).toJavaFormatString();
197+ }
198+
199+ /**
200+ * Returns a hexadecimal string representation of the
201+ * {@code double} argument. All characters mentioned below
202+ * are ASCII characters.
203+ *
204+ * <ul>
205+ * <li>If the argument is NaN, the result is the string
206+ * "{@code NaN}".
207+ * <li>Otherwise, the result is a string that represents the sign
208+ * and magnitude of the argument. If the sign is negative, the
209+ * first character of the result is '{@code -}'
210+ * (<code>'&#92;u002D'</code>); if the sign is positive, no sign
211+ * character appears in the result. As for the magnitude <i>m</i>:
212+ *
213+ * <ul>
214+ * <li>If <i>m</i> is infinity, it is represented by the string
215+ * {@code "Infinity"}; thus, positive infinity produces the
216+ * result {@code "Infinity"} and negative infinity produces
217+ * the result {@code "-Infinity"}.
218+ *
219+ * <li>If <i>m</i> is zero, it is represented by the string
220+ * {@code "0x0.0p0"}; thus, negative zero produces the result
221+ * {@code "-0x0.0p0"} and positive zero produces the result
222+ * {@code "0x0.0p0"}.
223+ *
224+ * <li>If <i>m</i> is a {@code double} value with a
225+ * normalized representation, substrings are used to represent the
226+ * significand and exponent fields. The significand is
227+ * represented by the characters {@code "0x1."}
228+ * followed by a lowercase hexadecimal representation of the rest
229+ * of the significand as a fraction. Trailing zeros in the
230+ * hexadecimal representation are removed unless all the digits
231+ * are zero, in which case a single zero is used. Next, the
232+ * exponent is represented by {@code "p"} followed
233+ * by a decimal string of the unbiased exponent as if produced by
234+ * a call to {@link Integer#toString(int) Integer.toString} on the
235+ * exponent value.
236+ *
237+ * <li>If <i>m</i> is a {@code double} value with a subnormal
238+ * representation, the significand is represented by the
239+ * characters {@code "0x0."} followed by a
240+ * hexadecimal representation of the rest of the significand as a
241+ * fraction. Trailing zeros in the hexadecimal representation are
242+ * removed. Next, the exponent is represented by
243+ * {@code "p-1022"}. Note that there must be at
244+ * least one nonzero digit in a subnormal significand.
245+ *
246+ * </ul>
247+ *
248+ * </ul>
249+ *
250+ * <table border>
251+ * <caption><h3>Examples</h3></caption>
252+ * <tr><th>Floating-point Value</th><th>Hexadecimal String</th>
253+ * <tr><td>{@code 1.0}</td> <td>{@code 0x1.0p0}</td>
254+ * <tr><td>{@code -1.0}</td> <td>{@code -0x1.0p0}</td>
255+ * <tr><td>{@code 2.0}</td> <td>{@code 0x1.0p1}</td>
256+ * <tr><td>{@code 3.0}</td> <td>{@code 0x1.8p1}</td>
257+ * <tr><td>{@code 0.5}</td> <td>{@code 0x1.0p-1}</td>
258+ * <tr><td>{@code 0.25}</td> <td>{@code 0x1.0p-2}</td>
259+ * <tr><td>{@code Double.MAX_VALUE}</td>
260+ * <td>{@code 0x1.fffffffffffffp1023}</td>
261+ * <tr><td>{@code Minimum Normal Value}</td>
262+ * <td>{@code 0x1.0p-1022}</td>
263+ * <tr><td>{@code Maximum Subnormal Value}</td>
264+ * <td>{@code 0x0.fffffffffffffp-1022}</td>
265+ * <tr><td>{@code Double.MIN_VALUE}</td>
266+ * <td>{@code 0x0.0000000000001p-1022}</td>
267+ * </table>
268+ * @param d the {@code double} to be converted.
269+ * @return a hex string representation of the argument.
270+ * @since 1.5
271+ * @author Joseph D. Darcy
272+ */
273+ public static String toHexString(double d) {
274+ /*
275+ * Modeled after the "a" conversion specifier in C99, section
276+ * 7.19.6.1; however, the output of this method is more
277+ * tightly specified.
278+ */
279+ if (!FpUtils.isFinite(d) )
280+ // For infinity and NaN, use the decimal output.
281+ return Double.toString(d);
282+ else {
283+ // Initialized to maximum size of output.
284+ StringBuffer answer = new StringBuffer(24);
285+
286+ if (FpUtils.rawCopySign(1.0, d) == -1.0) // value is negative,
287+ answer.append("-"); // so append sign info
288+
289+ answer.append("0x");
290+
291+ d = Math.abs(d);
292+
293+ if(d == 0.0) {
294+ answer.append("0.0p0");
295+ }
296+ else {
297+ boolean subnormal = (d < DoubleConsts.MIN_NORMAL);
298+
299+ // Isolate significand bits and OR in a high-order bit
300+ // so that the string representation has a known
301+ // length.
302+ long signifBits = (Double.doubleToLongBits(d)
303+ & DoubleConsts.SIGNIF_BIT_MASK) |
304+ 0x1000000000000000L;
305+
306+ // Subnormal values have a 0 implicit bit; normal
307+ // values have a 1 implicit bit.
308+ answer.append(subnormal ? "0." : "1.");
309+
310+ // Isolate the low-order 13 digits of the hex
311+ // representation. If all the digits are zero,
312+ // replace with a single 0; otherwise, remove all
313+ // trailing zeros.
314+ String signif = Long.toHexString(signifBits).substring(3,16);
315+ answer.append(signif.equals("0000000000000") ? // 13 zeros
316+ "0":
317+ signif.replaceFirst("0{1,12}$", ""));
318+
319+ // If the value is subnormal, use the E_min exponent
320+ // value for double; otherwise, extract and report d's
321+ // exponent (the representation of a subnormal uses
322+ // E_min -1).
323+ answer.append("p" + (subnormal ?
324+ DoubleConsts.MIN_EXPONENT:
325+ FpUtils.getExponent(d) ));
326+ }
327+ return answer.toString();
328+ }
329+ }
330+
331+ /**
332+ * Returns a {@code Double} object holding the
333+ * {@code double} value represented by the argument string
334+ * {@code s}.
335+ *
336+ * <p>If {@code s} is {@code null}, then a
337+ * {@code NullPointerException} is thrown.
338+ *
339+ * <p>Leading and trailing whitespace characters in {@code s}
340+ * are ignored. Whitespace is removed as if by the {@link
341+ * String#trim} method; that is, both ASCII space and control
342+ * characters are removed. The rest of {@code s} should
343+ * constitute a <i>FloatValue</i> as described by the lexical
344+ * syntax rules:
345+ *
346+ * <blockquote>
347+ * <dl>
348+ * <dt><i>FloatValue:</i>
349+ * <dd><i>Sign<sub>opt</sub></i> {@code NaN}
350+ * <dd><i>Sign<sub>opt</sub></i> {@code Infinity}
351+ * <dd><i>Sign<sub>opt</sub> FloatingPointLiteral</i>
352+ * <dd><i>Sign<sub>opt</sub> HexFloatingPointLiteral</i>
353+ * <dd><i>SignedInteger</i>
354+ * </dl>
355+ *
356+ * <p>
357+ *
358+ * <dl>
359+ * <dt><i>HexFloatingPointLiteral</i>:
360+ * <dd> <i>HexSignificand BinaryExponent FloatTypeSuffix<sub>opt</sub></i>
361+ * </dl>
362+ *
363+ * <p>
364+ *
365+ * <dl>
366+ * <dt><i>HexSignificand:</i>
367+ * <dd><i>HexNumeral</i>
368+ * <dd><i>HexNumeral</i> {@code .}
369+ * <dd>{@code 0x} <i>HexDigits<sub>opt</sub>
370+ * </i>{@code .}<i> HexDigits</i>
371+ * <dd>{@code 0X}<i> HexDigits<sub>opt</sub>
372+ * </i>{@code .} <i>HexDigits</i>
373+ * </dl>
374+ *
375+ * <p>
376+ *
377+ * <dl>
378+ * <dt><i>BinaryExponent:</i>
379+ * <dd><i>BinaryExponentIndicator SignedInteger</i>
380+ * </dl>
381+ *
382+ * <p>
383+ *
384+ * <dl>
385+ * <dt><i>BinaryExponentIndicator:</i>
386+ * <dd>{@code p}
387+ * <dd>{@code P}
388+ * </dl>
389+ *
390+ * </blockquote>
391+ *
392+ * where <i>Sign</i>, <i>FloatingPointLiteral</i>,
393+ * <i>HexNumeral</i>, <i>HexDigits</i>, <i>SignedInteger</i> and
394+ * <i>FloatTypeSuffix</i> are as defined in the lexical structure
395+ * sections of
396+ * <cite>The Java&trade; Language Specification</cite>,
397+ * except that underscores are not accepted between digits.
398+ * If {@code s} does not have the form of
399+ * a <i>FloatValue</i>, then a {@code NumberFormatException}
400+ * is thrown. Otherwise, {@code s} is regarded as
401+ * representing an exact decimal value in the usual
402+ * "computerized scientific notation" or as an exact
403+ * hexadecimal value; this exact numerical value is then
404+ * conceptually converted to an "infinitely precise"
405+ * binary value that is then rounded to type {@code double}
406+ * by the usual round-to-nearest rule of IEEE 754 floating-point
407+ * arithmetic, which includes preserving the sign of a zero
408+ * value.
409+ *
410+ * Note that the round-to-nearest rule also implies overflow and
411+ * underflow behaviour; if the exact value of {@code s} is large
412+ * enough in magnitude (greater than or equal to ({@link
413+ * #MAX_VALUE} + {@link Math#ulp(double) ulp(MAX_VALUE)}/2),
414+ * rounding to {@code double} will result in an infinity and if the
415+ * exact value of {@code s} is small enough in magnitude (less
416+ * than or equal to {@link #MIN_VALUE}/2), rounding to float will
417+ * result in a zero.
418+ *
419+ * Finally, after rounding a {@code Double} object representing
420+ * this {@code double} value is returned.
421+ *
422+ * <p> To interpret localized string representations of a
423+ * floating-point value, use subclasses of {@link
424+ * java.text.NumberFormat}.
425+ *
426+ * <p>Note that trailing format specifiers, specifiers that
427+ * determine the type of a floating-point literal
428+ * ({@code 1.0f} is a {@code float} value;
429+ * {@code 1.0d} is a {@code double} value), do
430+ * <em>not</em> influence the results of this method. In other
431+ * words, the numerical value of the input string is converted
432+ * directly to the target floating-point type. The two-step
433+ * sequence of conversions, string to {@code float} followed
434+ * by {@code float} to {@code double}, is <em>not</em>
435+ * equivalent to converting a string directly to
436+ * {@code double}. For example, the {@code float}
437+ * literal {@code 0.1f} is equal to the {@code double}
438+ * value {@code 0.10000000149011612}; the {@code float}
439+ * literal {@code 0.1f} represents a different numerical
440+ * value than the {@code double} literal
441+ * {@code 0.1}. (The numerical value 0.1 cannot be exactly
442+ * represented in a binary floating-point number.)
443+ *
444+ * <p>To avoid calling this method on an invalid string and having
445+ * a {@code NumberFormatException} be thrown, the regular
446+ * expression below can be used to screen the input string:
447+ *
448+ * <code>
449+ * <pre>
450+ * final String Digits = "(\\p{Digit}+)";
451+ * final String HexDigits = "(\\p{XDigit}+)";
452+ * // an exponent is 'e' or 'E' followed by an optionally
453+ * // signed decimal integer.
454+ * final String Exp = "[eE][+-]?"+Digits;
455+ * final String fpRegex =
456+ * ("[\\x00-\\x20]*"+ // Optional leading "whitespace"
457+ * "[+-]?(" + // Optional sign character
458+ * "NaN|" + // "NaN" string
459+ * "Infinity|" + // "Infinity" string
460+ *
461+ * // A decimal floating-point string representing a finite positive
462+ * // number without a leading sign has at most five basic pieces:
463+ * // Digits . Digits ExponentPart FloatTypeSuffix
464+ * //
465+ * // Since this method allows integer-only strings as input
466+ * // in addition to strings of floating-point literals, the
467+ * // two sub-patterns below are simplifications of the grammar
468+ * // productions from section 3.10.2 of
469+ * // <cite>The Java&trade; Language Specification</cite>.
470+ *
471+ * // Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt
472+ * "((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+
473+ *
474+ * // . Digits ExponentPart_opt FloatTypeSuffix_opt
475+ * "(\\.("+Digits+")("+Exp+")?)|"+
476+ *
477+ * // Hexadecimal strings
478+ * "((" +
479+ * // 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt
480+ * "(0[xX]" + HexDigits + "(\\.)?)|" +
481+ *
482+ * // 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt
483+ * "(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" +
484+ *
485+ * ")[pP][+-]?" + Digits + "))" +
486+ * "[fFdD]?))" +
487+ * "[\\x00-\\x20]*");// Optional trailing "whitespace"
488+ *
489+ * if (Pattern.matches(fpRegex, myString))
490+ * Double.valueOf(myString); // Will not throw NumberFormatException
491+ * else {
492+ * // Perform suitable alternative action
493+ * }
494+ * </pre>
495+ * </code>
496+ *
497+ * @param s the string to be parsed.
498+ * @return a {@code Double} object holding the value
499+ * represented by the {@code String} argument.
500+ * @throws NumberFormatException if the string does not contain a
501+ * parsable number.
502+ */
503+ public static Double valueOf(String s) throws NumberFormatException {
504+ return new Double(FloatingDecimal.readJavaFormatString(s).doubleValue());
505+ }
506+
507+ /**
508+ * Returns a {@code Double} instance representing the specified
509+ * {@code double} value.
510+ * If a new {@code Double} instance is not required, this method
511+ * should generally be used in preference to the constructor
512+ * {@link #Double(double)}, as this method is likely to yield
513+ * significantly better space and time performance by caching
514+ * frequently requested values.
515+ *
516+ * @param d a double value.
517+ * @return a {@code Double} instance representing {@code d}.
518+ * @since 1.5
519+ */
520+ public static Double valueOf(double d) {
521+ return new Double(d);
522+ }
523+
524+ /**
525+ * Returns a new {@code double} initialized to the value
526+ * represented by the specified {@code String}, as performed
527+ * by the {@code valueOf} method of class
528+ * {@code Double}.
529+ *
530+ * @param s the string to be parsed.
531+ * @return the {@code double} value represented by the string
532+ * argument.
533+ * @throws NullPointerException if the string is null
534+ * @throws NumberFormatException if the string does not contain
535+ * a parsable {@code double}.
536+ * @see java.lang.Double#valueOf(String)
537+ * @since 1.2
538+ */
539+ public static double parseDouble(String s) throws NumberFormatException {
540+ return FloatingDecimal.readJavaFormatString(s).doubleValue();
541+ }
542+
543+ /**
544+ * Returns {@code true} if the specified number is a
545+ * Not-a-Number (NaN) value, {@code false} otherwise.
546+ *
547+ * @param v the value to be tested.
548+ * @return {@code true} if the value of the argument is NaN;
549+ * {@code false} otherwise.
550+ */
551+ static public boolean isNaN(double v) {
552+ return (v != v);
553+ }
554+
555+ /**
556+ * Returns {@code true} if the specified number is infinitely
557+ * large in magnitude, {@code false} otherwise.
558+ *
559+ * @param v the value to be tested.
560+ * @return {@code true} if the value of the argument is positive
561+ * infinity or negative infinity; {@code false} otherwise.
562+ */
563+ static public boolean isInfinite(double v) {
564+ return (v == POSITIVE_INFINITY) || (v == NEGATIVE_INFINITY);
565+ }
566+
567+ /**
568+ * The value of the Double.
569+ *
570+ * @serial
571+ */
572+ private final double value;
573+
574+ /**
575+ * Constructs a newly allocated {@code Double} object that
576+ * represents the primitive {@code double} argument.
577+ *
578+ * @param value the value to be represented by the {@code Double}.
579+ */
580+ public Double(double value) {
581+ this.value = value;
582+ }
583+
584+ /**
585+ * Constructs a newly allocated {@code Double} object that
586+ * represents the floating-point value of type {@code double}
587+ * represented by the string. The string is converted to a
588+ * {@code double} value as if by the {@code valueOf} method.
589+ *
590+ * @param s a string to be converted to a {@code Double}.
591+ * @throws NumberFormatException if the string does not contain a
592+ * parsable number.
593+ * @see java.lang.Double#valueOf(java.lang.String)
594+ */
595+ public Double(String s) throws NumberFormatException {
596+ // REMIND: this is inefficient
597+ this(valueOf(s).doubleValue());
598+ }
599+
600+ /**
601+ * Returns {@code true} if this {@code Double} value is
602+ * a Not-a-Number (NaN), {@code false} otherwise.
603+ *
604+ * @return {@code true} if the value represented by this object is
605+ * NaN; {@code false} otherwise.
606+ */
607+ public boolean isNaN() {
608+ return isNaN(value);
609+ }
610+
611+ /**
612+ * Returns {@code true} if this {@code Double} value is
613+ * infinitely large in magnitude, {@code false} otherwise.
614+ *
615+ * @return {@code true} if the value represented by this object is
616+ * positive infinity or negative infinity;
617+ * {@code false} otherwise.
618+ */
619+ public boolean isInfinite() {
620+ return isInfinite(value);
621+ }
622+
623+ /**
624+ * Returns a string representation of this {@code Double} object.
625+ * The primitive {@code double} value represented by this
626+ * object is converted to a string exactly as if by the method
627+ * {@code toString} of one argument.
628+ *
629+ * @return a {@code String} representation of this object.
630+ * @see java.lang.Double#toString(double)
631+ */
632+ public String toString() {
633+ return toString(value);
634+ }
635+
636+ /**
637+ * Returns the value of this {@code Double} as a {@code byte} (by
638+ * casting to a {@code byte}).
639+ *
640+ * @return the {@code double} value represented by this object
641+ * converted to type {@code byte}
642+ * @since JDK1.1
643+ */
644+ public byte byteValue() {
645+ return (byte)value;
646+ }
647+
648+ /**
649+ * Returns the value of this {@code Double} as a
650+ * {@code short} (by casting to a {@code short}).
651+ *
652+ * @return the {@code double} value represented by this object
653+ * converted to type {@code short}
654+ * @since JDK1.1
655+ */
656+ public short shortValue() {
657+ return (short)value;
658+ }
659+
660+ /**
661+ * Returns the value of this {@code Double} as an
662+ * {@code int} (by casting to type {@code int}).
663+ *
664+ * @return the {@code double} value represented by this object
665+ * converted to type {@code int}
666+ */
667+ public int intValue() {
668+ return (int)value;
669+ }
670+
671+ /**
672+ * Returns the value of this {@code Double} as a
673+ * {@code long} (by casting to type {@code long}).
674+ *
675+ * @return the {@code double} value represented by this object
676+ * converted to type {@code long}
677+ */
678+ public long longValue() {
679+ return (long)value;
680+ }
681+
682+ /**
683+ * Returns the {@code float} value of this
684+ * {@code Double} object.
685+ *
686+ * @return the {@code double} value represented by this object
687+ * converted to type {@code float}
688+ * @since JDK1.0
689+ */
690+ public float floatValue() {
691+ return (float)value;
692+ }
693+
694+ /**
695+ * Returns the {@code double} value of this
696+ * {@code Double} object.
697+ *
698+ * @return the {@code double} value represented by this object
699+ */
700+ public double doubleValue() {
701+ return (double)value;
702+ }
703+
704+ /**
705+ * Returns a hash code for this {@code Double} object. The
706+ * result is the exclusive OR of the two halves of the
707+ * {@code long} integer bit representation, exactly as
708+ * produced by the method {@link #doubleToLongBits(double)}, of
709+ * the primitive {@code double} value represented by this
710+ * {@code Double} object. That is, the hash code is the value
711+ * of the expression:
712+ *
713+ * <blockquote>
714+ * {@code (int)(v^(v>>>32))}
715+ * </blockquote>
716+ *
717+ * where {@code v} is defined by:
718+ *
719+ * <blockquote>
720+ * {@code long v = Double.doubleToLongBits(this.doubleValue());}
721+ * </blockquote>
722+ *
723+ * @return a {@code hash code} value for this object.
724+ */
725+ public int hashCode() {
726+ long bits = doubleToLongBits(value);
727+ return (int)(bits ^ (bits >>> 32));
728+ }
729+
730+ /**
731+ * Compares this object against the specified object. The result
732+ * is {@code true} if and only if the argument is not
733+ * {@code null} and is a {@code Double} object that
734+ * represents a {@code double} that has the same value as the
735+ * {@code double} represented by this object. For this
736+ * purpose, two {@code double} values are considered to be
737+ * the same if and only if the method {@link
738+ * #doubleToLongBits(double)} returns the identical
739+ * {@code long} value when applied to each.
740+ *
741+ * <p>Note that in most cases, for two instances of class
742+ * {@code Double}, {@code d1} and {@code d2}, the
743+ * value of {@code d1.equals(d2)} is {@code true} if and
744+ * only if
745+ *
746+ * <blockquote>
747+ * {@code d1.doubleValue() == d2.doubleValue()}
748+ * </blockquote>
749+ *
750+ * <p>also has the value {@code true}. However, there are two
751+ * exceptions:
752+ * <ul>
753+ * <li>If {@code d1} and {@code d2} both represent
754+ * {@code Double.NaN}, then the {@code equals} method
755+ * returns {@code true}, even though
756+ * {@code Double.NaN==Double.NaN} has the value
757+ * {@code false}.
758+ * <li>If {@code d1} represents {@code +0.0} while
759+ * {@code d2} represents {@code -0.0}, or vice versa,
760+ * the {@code equal} test has the value {@code false},
761+ * even though {@code +0.0==-0.0} has the value {@code true}.
762+ * </ul>
763+ * This definition allows hash tables to operate properly.
764+ * @param obj the object to compare with.
765+ * @return {@code true} if the objects are the same;
766+ * {@code false} otherwise.
767+ * @see java.lang.Double#doubleToLongBits(double)
768+ */
769+ public boolean equals(Object obj) {
770+ return (obj instanceof Double)
771+ && (doubleToLongBits(((Double)obj).value) ==
772+ doubleToLongBits(value));
773+ }
774+
775+ /**
776+ * Returns a representation of the specified floating-point value
777+ * according to the IEEE 754 floating-point "double
778+ * format" bit layout.
779+ *
780+ * <p>Bit 63 (the bit that is selected by the mask
781+ * {@code 0x8000000000000000L}) represents the sign of the
782+ * floating-point number. Bits
783+ * 62-52 (the bits that are selected by the mask
784+ * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0
785+ * (the bits that are selected by the mask
786+ * {@code 0x000fffffffffffffL}) represent the significand
787+ * (sometimes called the mantissa) of the floating-point number.
788+ *
789+ * <p>If the argument is positive infinity, the result is
790+ * {@code 0x7ff0000000000000L}.
791+ *
792+ * <p>If the argument is negative infinity, the result is
793+ * {@code 0xfff0000000000000L}.
794+ *
795+ * <p>If the argument is NaN, the result is
796+ * {@code 0x7ff8000000000000L}.
797+ *
798+ * <p>In all cases, the result is a {@code long} integer that, when
799+ * given to the {@link #longBitsToDouble(long)} method, will produce a
800+ * floating-point value the same as the argument to
801+ * {@code doubleToLongBits} (except all NaN values are
802+ * collapsed to a single "canonical" NaN value).
803+ *
804+ * @param value a {@code double} precision floating-point number.
805+ * @return the bits that represent the floating-point number.
806+ */
807+ public static long doubleToLongBits(double value) {
808+ long result = doubleToRawLongBits(value);
809+ // Check for NaN based on values of bit fields, maximum
810+ // exponent and nonzero significand.
811+ if ( ((result & DoubleConsts.EXP_BIT_MASK) ==
812+ DoubleConsts.EXP_BIT_MASK) &&
813+ (result & DoubleConsts.SIGNIF_BIT_MASK) != 0L)
814+ result = 0x7ff8000000000000L;
815+ return result;
816+ }
817+
818+ /**
819+ * Returns a representation of the specified floating-point value
820+ * according to the IEEE 754 floating-point "double
821+ * format" bit layout, preserving Not-a-Number (NaN) values.
822+ *
823+ * <p>Bit 63 (the bit that is selected by the mask
824+ * {@code 0x8000000000000000L}) represents the sign of the
825+ * floating-point number. Bits
826+ * 62-52 (the bits that are selected by the mask
827+ * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0
828+ * (the bits that are selected by the mask
829+ * {@code 0x000fffffffffffffL}) represent the significand
830+ * (sometimes called the mantissa) of the floating-point number.
831+ *
832+ * <p>If the argument is positive infinity, the result is
833+ * {@code 0x7ff0000000000000L}.
834+ *
835+ * <p>If the argument is negative infinity, the result is
836+ * {@code 0xfff0000000000000L}.
837+ *
838+ * <p>If the argument is NaN, the result is the {@code long}
839+ * integer representing the actual NaN value. Unlike the
840+ * {@code doubleToLongBits} method,
841+ * {@code doubleToRawLongBits} does not collapse all the bit
842+ * patterns encoding a NaN to a single "canonical" NaN
843+ * value.
844+ *
845+ * <p>In all cases, the result is a {@code long} integer that,
846+ * when given to the {@link #longBitsToDouble(long)} method, will
847+ * produce a floating-point value the same as the argument to
848+ * {@code doubleToRawLongBits}.
849+ *
850+ * @param value a {@code double} precision floating-point number.
851+ * @return the bits that represent the floating-point number.
852+ * @since 1.3
853+ */
854+ public static native long doubleToRawLongBits(double value);
855+
856+ /**
857+ * Returns the {@code double} value corresponding to a given
858+ * bit representation.
859+ * The argument is considered to be a representation of a
860+ * floating-point value according to the IEEE 754 floating-point
861+ * "double format" bit layout.
862+ *
863+ * <p>If the argument is {@code 0x7ff0000000000000L}, the result
864+ * is positive infinity.
865+ *
866+ * <p>If the argument is {@code 0xfff0000000000000L}, the result
867+ * is negative infinity.
868+ *
869+ * <p>If the argument is any value in the range
870+ * {@code 0x7ff0000000000001L} through
871+ * {@code 0x7fffffffffffffffL} or in the range
872+ * {@code 0xfff0000000000001L} through
873+ * {@code 0xffffffffffffffffL}, the result is a NaN. No IEEE
874+ * 754 floating-point operation provided by Java can distinguish
875+ * between two NaN values of the same type with different bit
876+ * patterns. Distinct values of NaN are only distinguishable by
877+ * use of the {@code Double.doubleToRawLongBits} method.
878+ *
879+ * <p>In all other cases, let <i>s</i>, <i>e</i>, and <i>m</i> be three
880+ * values that can be computed from the argument:
881+ *
882+ * <blockquote><pre>
883+ * int s = ((bits &gt;&gt; 63) == 0) ? 1 : -1;
884+ * int e = (int)((bits &gt;&gt; 52) & 0x7ffL);
885+ * long m = (e == 0) ?
886+ * (bits & 0xfffffffffffffL) &lt;&lt; 1 :
887+ * (bits & 0xfffffffffffffL) | 0x10000000000000L;
888+ * </pre></blockquote>
889+ *
890+ * Then the floating-point result equals the value of the mathematical
891+ * expression <i>s</i>&middot;<i>m</i>&middot;2<sup><i>e</i>-1075</sup>.
892+ *
893+ * <p>Note that this method may not be able to return a
894+ * {@code double} NaN with exactly same bit pattern as the
895+ * {@code long} argument. IEEE 754 distinguishes between two
896+ * kinds of NaNs, quiet NaNs and <i>signaling NaNs</i>. The
897+ * differences between the two kinds of NaN are generally not
898+ * visible in Java. Arithmetic operations on signaling NaNs turn
899+ * them into quiet NaNs with a different, but often similar, bit
900+ * pattern. However, on some processors merely copying a
901+ * signaling NaN also performs that conversion. In particular,
902+ * copying a signaling NaN to return it to the calling method
903+ * may perform this conversion. So {@code longBitsToDouble}
904+ * may not be able to return a {@code double} with a
905+ * signaling NaN bit pattern. Consequently, for some
906+ * {@code long} values,
907+ * {@code doubleToRawLongBits(longBitsToDouble(start))} may
908+ * <i>not</i> equal {@code start}. Moreover, which
909+ * particular bit patterns represent signaling NaNs is platform
910+ * dependent; although all NaN bit patterns, quiet or signaling,
911+ * must be in the NaN range identified above.
912+ *
913+ * @param bits any {@code long} integer.
914+ * @return the {@code double} floating-point value with the same
915+ * bit pattern.
916+ */
917+ public static native double longBitsToDouble(long bits);
918+
919+ /**
920+ * Compares two {@code Double} objects numerically. There
921+ * are two ways in which comparisons performed by this method
922+ * differ from those performed by the Java language numerical
923+ * comparison operators ({@code <, <=, ==, >=, >})
924+ * when applied to primitive {@code double} values:
925+ * <ul><li>
926+ * {@code Double.NaN} is considered by this method
927+ * to be equal to itself and greater than all other
928+ * {@code double} values (including
929+ * {@code Double.POSITIVE_INFINITY}).
930+ * <li>
931+ * {@code 0.0d} is considered by this method to be greater
932+ * than {@code -0.0d}.
933+ * </ul>
934+ * This ensures that the <i>natural ordering</i> of
935+ * {@code Double} objects imposed by this method is <i>consistent
936+ * with equals</i>.
937+ *
938+ * @param anotherDouble the {@code Double} to be compared.
939+ * @return the value {@code 0} if {@code anotherDouble} is
940+ * numerically equal to this {@code Double}; a value
941+ * less than {@code 0} if this {@code Double}
942+ * is numerically less than {@code anotherDouble};
943+ * and a value greater than {@code 0} if this
944+ * {@code Double} is numerically greater than
945+ * {@code anotherDouble}.
946+ *
947+ * @since 1.2
948+ */
949+ public int compareTo(Double anotherDouble) {
950+ return Double.compare(value, anotherDouble.value);
951+ }
952+
953+ /**
954+ * Compares the two specified {@code double} values. The sign
955+ * of the integer value returned is the same as that of the
956+ * integer that would be returned by the call:
957+ * <pre>
958+ * new Double(d1).compareTo(new Double(d2))
959+ * </pre>
960+ *
961+ * @param d1 the first {@code double} to compare
962+ * @param d2 the second {@code double} to compare
963+ * @return the value {@code 0} if {@code d1} is
964+ * numerically equal to {@code d2}; a value less than
965+ * {@code 0} if {@code d1} is numerically less than
966+ * {@code d2}; and a value greater than {@code 0}
967+ * if {@code d1} is numerically greater than
968+ * {@code d2}.
969+ * @since 1.4
970+ */
971+ public static int compare(double d1, double d2) {
972+ if (d1 < d2)
973+ return -1; // Neither val is NaN, thisVal is smaller
974+ if (d1 > d2)
975+ return 1; // Neither val is NaN, thisVal is larger
976+
977+ // Cannot use doubleToRawLongBits because of possibility of NaNs.
978+ long thisBits = Double.doubleToLongBits(d1);
979+ long anotherBits = Double.doubleToLongBits(d2);
980+
981+ return (thisBits == anotherBits ? 0 : // Values are equal
982+ (thisBits < anotherBits ? -1 : // (-0.0, 0.0) or (!NaN, NaN)
983+ 1)); // (0.0, -0.0) or (NaN, !NaN)
984+ }
985+
986+ /** use serialVersionUID from JDK 1.0.2 for interoperability */
987+ private static final long serialVersionUID = -9172774392245257468L;
988+}