Menu
▾
▴
[Jnode-svn-commits] SF.net SVN: jnode: [3193] trunk/core/src
|
From: <ls...@us...> - 2007-05-13 17:02:24
|
Revision: 3193
http://jnode.svn.sourceforge.net/jnode/?rev=3193&view=rev
Author: lsantha
Date: 2007-05-13 10:02:22 -0700 (Sun, 13 May 2007)
Log Message:
-----------
First merges of OpenJDK.
Added Paths:
-----------
trunk/core/src/openjdk/
trunk/core/src/openjdk/java/
trunk/core/src/openjdk/java/java/
trunk/core/src/openjdk/java/java/lang/
trunk/core/src/openjdk/java/java/lang/Double.java
Added: trunk/core/src/openjdk/java/java/lang/Double.java
===================================================================
--- trunk/core/src/openjdk/java/java/lang/Double.java (rev 0)
+++ trunk/core/src/openjdk/java/java/lang/Double.java 2007-05-13 17:02:22 UTC (rev 3193)
@@ -0,0 +1,975 @@
+/*
+ * Copyright 1994-2006 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.lang;
+
+import sun.misc.FloatingDecimal;
+import sun.misc.FpUtils;
+import sun.misc.DoubleConsts;
+
+/**
+ * The {@code Double} class wraps a value of the primitive type
+ * {@code double} in an object. An object of type
+ * {@code Double} contains a single field whose type is
+ * {@code double}.
+ *
+ * <p>In addition, this class provides several methods for converting a
+ * {@code double} to a {@code String} and a
+ * {@code String} to a {@code double}, as well as other
+ * constants and methods useful when dealing with a
+ * {@code double}.
+ *
+ * @author Lee Boynton
+ * @author Arthur van Hoff
+ * @author Joseph D. Darcy
+ * @version 1.107, 05/05/07
+ * @since JDK1.0
+ */
+public final class Double extends Number implements Comparable<Double> {
+ /**
+ * A constant holding the positive infinity of type
+ * {@code double}. It is equal to the value returned by
+ * {@code Double.longBitsToDouble(0x7ff0000000000000L)}.
+ */
+ public static final double POSITIVE_INFINITY = 1.0 / 0.0;
+
+ /**
+ * A constant holding the negative infinity of type
+ * {@code double}. It is equal to the value returned by
+ * {@code Double.longBitsToDouble(0xfff0000000000000L)}.
+ */
+ public static final double NEGATIVE_INFINITY = -1.0 / 0.0;
+
+ /**
+ * A constant holding a Not-a-Number (NaN) value of type
+ * {@code double}. It is equivalent to the value returned by
+ * {@code Double.longBitsToDouble(0x7ff8000000000000L)}.
+ */
+ public static final double NaN = 0.0d / 0.0;
+
+ /**
+ * A constant holding the largest positive finite value of type
+ * {@code double},
+ * (2-2<sup>-52</sup>)·2<sup>1023</sup>. It is equal to
+ * the hexadecimal floating-point literal
+ * {@code 0x1.fffffffffffffP+1023} and also equal to
+ * {@code Double.longBitsToDouble(0x7fefffffffffffffL)}.
+ */
+ public static final double MAX_VALUE = 0x1.fffffffffffffP+1023; // 1.7976931348623157e+308
+
+ /**
+ * A constant holding the smallest positive normal value of type
+ * {@code double}, 2<sup>-1022</sup>. It is equal to the
+ * hexadecimal floating-point literal {@code 0x1.0p-1022} and also
+ * equal to {@code Double.longBitsToDouble(0x0010000000000000L)}.
+ *
+ * @since 1.6
+ */
+ public static final double MIN_NORMAL = 0x1.0p-1022; // 2.2250738585072014E-308
+
+ /**
+ * A constant holding the smallest positive nonzero value of type
+ * {@code double}, 2<sup>-1074</sup>. It is equal to the
+ * hexadecimal floating-point literal
+ * {@code 0x0.0000000000001P-1022} and also equal to
+ * {@code Double.longBitsToDouble(0x1L)}.
+ */
+ public static final double MIN_VALUE = 0x0.0000000000001P-1022; // 4.9e-324
+
+ /**
+ * Maximum exponent a finite {@code double} variable may have.
+ * It is equal to the value returned by
+ * {@code Math.getExponent(Double.MAX_VALUE)}.
+ *
+ * @since 1.6
+ */
+ public static final int MAX_EXPONENT = 1023;
+
+ /**
+ * Minimum exponent a normalized {@code double} variable may
+ * have. It is equal to the value returned by
+ * {@code Math.getExponent(Double.MIN_NORMAL)}.
+ *
+ * @since 1.6
+ */
+ public static final int MIN_EXPONENT = -1022;
+
+ /**
+ * The number of bits used to represent a {@code double} value.
+ *
+ * @since 1.5
+ */
+ public static final int SIZE = 64;
+
+ /**
+ * The {@code Class} instance representing the primitive type
+ * {@code double}.
+ *
+ * @since JDK1.1
+ */
+ public static final Class<Double> TYPE = (Class<Double>) Class.getPrimitiveClass("double");
+
+ /**
+ * Returns a string representation of the {@code double}
+ * argument. All characters mentioned below are ASCII characters.
+ * <ul>
+ * <li>If the argument is NaN, the result is the string
+ * "{@code NaN}".
+ * <li>Otherwise, the result is a string that represents the sign and
+ * magnitude (absolute value) of the argument. If the sign is negative,
+ * the first character of the result is '{@code -}'
+ * (<code>'\u002D'</code>); if the sign is positive, no sign character
+ * appears in the result. As for the magnitude <i>m</i>:
+ * <ul>
+ * <li>If <i>m</i> is infinity, it is represented by the characters
+ * {@code "Infinity"}; thus, positive infinity produces the result
+ * {@code "Infinity"} and negative infinity produces the result
+ * {@code "-Infinity"}.
+ *
+ * <li>If <i>m</i> is zero, it is represented by the characters
+ * {@code "0.0"}; thus, negative zero produces the result
+ * {@code "-0.0"} and positive zero produces the result
+ * {@code "0.0"}.
+ *
+ * <li>If <i>m</i> is greater than or equal to 10<sup>-3</sup> but less
+ * than 10<sup>7</sup>, then it is represented as the integer part of
+ * <i>m</i>, in decimal form with no leading zeroes, followed by
+ * '{@code .}' (<code>'\u002E'</code>), followed by one or
+ * more decimal digits representing the fractional part of <i>m</i>.
+ *
+ * <li>If <i>m</i> is less than 10<sup>-3</sup> or greater than or
+ * equal to 10<sup>7</sup>, then it is represented in so-called
+ * "computerized scientific notation." Let <i>n</i> be the unique
+ * integer such that 10<sup><i>n</i></sup> ≤ <i>m</i> {@literal <}
+ * 10<sup><i>n</i>+1</sup>; then let <i>a</i> be the
+ * mathematically exact quotient of <i>m</i> and
+ * 10<sup><i>n</i></sup> so that 1 ≤ <i>a</i> {@literal <} 10. The
+ * magnitude is then represented as the integer part of <i>a</i>,
+ * as a single decimal digit, followed by '{@code .}'
+ * (<code>'\u002E'</code>), followed by decimal digits
+ * representing the fractional part of <i>a</i>, followed by the
+ * letter '{@code E}' (<code>'\u0045'</code>), followed
+ * by a representation of <i>n</i> as a decimal integer, as
+ * produced by the method {@link Integer#toString(int)}.
+ * </ul>
+ * </ul>
+ * How many digits must be printed for the fractional part of
+ * <i>m</i> or <i>a</i>? There must be at least one digit to represent
+ * the fractional part, and beyond that as many, but only as many, more
+ * digits as are needed to uniquely distinguish the argument value from
+ * adjacent values of type {@code double}. That is, suppose that
+ * <i>x</i> is the exact mathematical value represented by the decimal
+ * representation produced by this method for a finite nonzero argument
+ * <i>d</i>. Then <i>d</i> must be the {@code double} value nearest
+ * to <i>x</i>; or if two {@code double} values are equally close
+ * to <i>x</i>, then <i>d</i> must be one of them and the least
+ * significant bit of the significand of <i>d</i> must be {@code 0}.
+ *
+ * <p>To create localized string representations of a floating-point
+ * value, use subclasses of {@link java.text.NumberFormat}.
+ *
+ * @param d the {@code double} to be converted.
+ * @return a string representation of the argument.
+ */
+ public static String toString(double d) {
+ return new FloatingDecimal(d).toJavaFormatString();
+ }
+
+ /**
+ * Returns a hexadecimal string representation of the
+ * {@code double} argument. All characters mentioned below
+ * are ASCII characters.
+ *
+ * <ul>
+ * <li>If the argument is NaN, the result is the string
+ * "{@code NaN}".
+ * <li>Otherwise, the result is a string that represents the sign
+ * and magnitude of the argument. If the sign is negative, the
+ * first character of the result is '{@code -}'
+ * (<code>'\u002D'</code>); if the sign is positive, no sign
+ * character appears in the result. As for the magnitude <i>m</i>:
+ *
+ * <ul>
+ * <li>If <i>m</i> is infinity, it is represented by the string
+ * {@code "Infinity"}; thus, positive infinity produces the
+ * result {@code "Infinity"} and negative infinity produces
+ * the result {@code "-Infinity"}.
+ *
+ * <li>If <i>m</i> is zero, it is represented by the string
+ * {@code "0x0.0p0"}; thus, negative zero produces the result
+ * {@code "-0x0.0p0"} and positive zero produces the result
+ * {@code "0x0.0p0"}.
+ *
+ * <li>If <i>m</i> is a {@code double} value with a
+ * normalized representation, substrings are used to represent the
+ * significand and exponent fields. The significand is
+ * represented by the characters {@code "0x1."}
+ * followed by a lowercase hexadecimal representation of the rest
+ * of the significand as a fraction. Trailing zeros in the
+ * hexadecimal representation are removed unless all the digits
+ * are zero, in which case a single zero is used. Next, the
+ * exponent is represented by {@code "p"} followed
+ * by a decimal string of the unbiased exponent as if produced by
+ * a call to {@link Integer#toString(int) Integer.toString} on the
+ * exponent value.
+ *
+ * <li>If <i>m</i> is a {@code double} value with a subnormal
+ * representation, the significand is represented by the
+ * characters {@code "0x0."} followed by a
+ * hexadecimal representation of the rest of the significand as a
+ * fraction. Trailing zeros in the hexadecimal representation are
+ * removed. Next, the exponent is represented by
+ * {@code "p-1022"}. Note that there must be at
+ * least one nonzero digit in a subnormal significand.
+ *
+ * </ul>
+ *
+ * </ul>
+ *
+ * <table border>
+ * <caption><h3>Examples</h3></caption>
+ * <tr><th>Floating-point Value</th><th>Hexadecimal String</th>
+ * <tr><td>{@code 1.0}</td> <td>{@code 0x1.0p0}</td>
+ * <tr><td>{@code -1.0}</td> <td>{@code -0x1.0p0}</td>
+ * <tr><td>{@code 2.0}</td> <td>{@code 0x1.0p1}</td>
+ * <tr><td>{@code 3.0}</td> <td>{@code 0x1.8p1}</td>
+ * <tr><td>{@code 0.5}</td> <td>{@code 0x1.0p-1}</td>
+ * <tr><td>{@code 0.25}</td> <td>{@code 0x1.0p-2}</td>
+ * <tr><td>{@code Double.MAX_VALUE}</td>
+ * <td>{@code 0x1.fffffffffffffp1023}</td>
+ * <tr><td>{@code Minimum Normal Value}</td>
+ * <td>{@code 0x1.0p-1022}</td>
+ * <tr><td>{@code Maximum Subnormal Value}</td>
+ * <td>{@code 0x0.fffffffffffffp-1022}</td>
+ * <tr><td>{@code Double.MIN_VALUE}</td>
+ * <td>{@code 0x0.0000000000001p-1022}</td>
+ * </table>
+ * @param d the {@code double} to be converted.
+ * @return a hex string representation of the argument.
+ * @since 1.5
+ * @author Joseph D. Darcy
+ */
+ public static String toHexString(double d) {
+ /*
+ * Modeled after the "a" conversion specifier in C99, section
+ * 7.19.6.1; however, the output of this method is more
+ * tightly specified.
+ */
+ if (!FpUtils.isFinite(d) )
+ // For infinity and NaN, use the decimal output.
+ return Double.toString(d);
+ else {
+ // Initialized to maximum size of output.
+ StringBuffer answer = new StringBuffer(24);
+
+ if (FpUtils.rawCopySign(1.0, d) == -1.0) // value is negative,
+ answer.append("-"); // so append sign info
+
+ answer.append("0x");
+
+ d = Math.abs(d);
+
+ if(d == 0.0) {
+ answer.append("0.0p0");
+ }
+ else {
+ boolean subnormal = (d < DoubleConsts.MIN_NORMAL);
+
+ // Isolate significand bits and OR in a high-order bit
+ // so that the string representation has a known
+ // length.
+ long signifBits = (Double.doubleToLongBits(d)
+ & DoubleConsts.SIGNIF_BIT_MASK) |
+ 0x1000000000000000L;
+
+ // Subnormal values have a 0 implicit bit; normal
+ // values have a 1 implicit bit.
+ answer.append(subnormal ? "0." : "1.");
+
+ // Isolate the low-order 13 digits of the hex
+ // representation. If all the digits are zero,
+ // replace with a single 0; otherwise, remove all
+ // trailing zeros.
+ String signif = Long.toHexString(signifBits).substring(3,16);
+ answer.append(signif.equals("0000000000000") ? // 13 zeros
+ "0":
+ signif.replaceFirst("0{1,12}$", ""));
+
+ // If the value is subnormal, use the E_min exponent
+ // value for double; otherwise, extract and report d's
+ // exponent (the representation of a subnormal uses
+ // E_min -1).
+ answer.append("p" + (subnormal ?
+ DoubleConsts.MIN_EXPONENT:
+ FpUtils.getExponent(d) ));
+ }
+ return answer.toString();
+ }
+ }
+
+ /**
+ * Returns a {@code Double} object holding the
+ * {@code double} value represented by the argument string
+ * {@code s}.
+ *
+ * <p>If {@code s} is {@code null}, then a
+ * {@code NullPointerException} is thrown.
+ *
+ * <p>Leading and trailing whitespace characters in {@code s}
+ * are ignored. Whitespace is removed as if by the {@link
+ * String#trim} method; that is, both ASCII space and control
+ * characters are removed. The rest of {@code s} should
+ * constitute a <i>FloatValue</i> as described by the lexical
+ * syntax rules:
+ *
+ * <blockquote>
+ * <dl>
+ * <dt><i>FloatValue:</i>
+ * <dd><i>Sign<sub>opt</sub></i> {@code NaN}
+ * <dd><i>Sign<sub>opt</sub></i> {@code Infinity}
+ * <dd><i>Sign<sub>opt</sub> FloatingPointLiteral</i>
+ * <dd><i>Sign<sub>opt</sub> HexFloatingPointLiteral</i>
+ * <dd><i>SignedInteger</i>
+ * </dl>
+ *
+ * <p>
+ *
+ * <dl>
+ * <dt><i>HexFloatingPointLiteral</i>:
+ * <dd> <i>HexSignificand BinaryExponent FloatTypeSuffix<sub>opt</sub></i>
+ * </dl>
+ *
+ * <p>
+ *
+ * <dl>
+ * <dt><i>HexSignificand:</i>
+ * <dd><i>HexNumeral</i>
+ * <dd><i>HexNumeral</i> {@code .}
+ * <dd>{@code 0x} <i>HexDigits<sub>opt</sub>
+ * </i>{@code .}<i> HexDigits</i>
+ * <dd>{@code 0X}<i> HexDigits<sub>opt</sub>
+ * </i>{@code .} <i>HexDigits</i>
+ * </dl>
+ *
+ * <p>
+ *
+ * <dl>
+ * <dt><i>BinaryExponent:</i>
+ * <dd><i>BinaryExponentIndicator SignedInteger</i>
+ * </dl>
+ *
+ * <p>
+ *
+ * <dl>
+ * <dt><i>BinaryExponentIndicator:</i>
+ * <dd>{@code p}
+ * <dd>{@code P}
+ * </dl>
+ *
+ * </blockquote>
+ *
+ * where <i>Sign</i>, <i>FloatingPointLiteral</i>,
+ * <i>HexNumeral</i>, <i>HexDigits</i>, <i>SignedInteger</i> and
+ * <i>FloatTypeSuffix</i> are as defined in the lexical structure
+ * sections of the of the <a
+ * href="http://java.sun.com/docs/books/jls/html/">Java Language
+ * Specification</a>. If {@code s} does not have the form of
+ * a <i>FloatValue</i>, then a {@code NumberFormatException}
+ * is thrown. Otherwise, {@code s} is regarded as
+ * representing an exact decimal value in the usual
+ * "computerized scientific notation" or as an exact
+ * hexadecimal value; this exact numerical value is then
+ * conceptually converted to an "infinitely precise"
+ * binary value that is then rounded to type {@code double}
+ * by the usual round-to-nearest rule of IEEE 754 floating-point
+ * arithmetic, which includes preserving the sign of a zero
+ * value. Finally, a {@code Double} object representing this
+ * {@code double} value is returned.
+ *
+ * <p> To interpret localized string representations of a
+ * floating-point value, use subclasses of {@link
+ * java.text.NumberFormat}.
+ *
+ * <p>Note that trailing format specifiers, specifiers that
+ * determine the type of a floating-point literal
+ * ({@code 1.0f} is a {@code float} value;
+ * {@code 1.0d} is a {@code double} value), do
+ * <em>not</em> influence the results of this method. In other
+ * words, the numerical value of the input string is converted
+ * directly to the target floating-point type. The two-step
+ * sequence of conversions, string to {@code float} followed
+ * by {@code float} to {@code double}, is <em>not</em>
+ * equivalent to converting a string directly to
+ * {@code double}. For example, the {@code float}
+ * literal {@code 0.1f} is equal to the {@code double}
+ * value {@code 0.10000000149011612}; the {@code float}
+ * literal {@code 0.1f} represents a different numerical
+ * value than the {@code double} literal
+ * {@code 0.1}. (The numerical value 0.1 cannot be exactly
+ * represented in a binary floating-point number.)
+ *
+ * <p>To avoid calling this method on an invalid string and having
+ * a {@code NumberFormatException} be thrown, the regular
+ * expression below can be used to screen the input string:
+ *
+ * <code>
+ * <pre>
+ * final String Digits = "(\\p{Digit}+)";
+ * final String HexDigits = "(\\p{XDigit}+)";
+ * // an exponent is 'e' or 'E' followed by an optionally
+ * // signed decimal integer.
+ * final String Exp = "[eE][+-]?"+Digits;
+ * final String fpRegex =
+ * ("[\\x00-\\x20]*"+ // Optional leading "whitespace"
+ * "[+-]?(" + // Optional sign character
+ * "NaN|" + // "NaN" string
+ * "Infinity|" + // "Infinity" string
+ *
+ * // A decimal floating-point string representing a finite positive
+ * // number without a leading sign has at most five basic pieces:
+ * // Digits . Digits ExponentPart FloatTypeSuffix
+ * //
+ * // Since this method allows integer-only strings as input
+ * // in addition to strings of floating-point literals, the
+ * // two sub-patterns below are simplifications of the grammar
+ * // productions from the Java Language Specification, 2nd
+ * // edition, section 3.10.2.
+ *
+ * // Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt
+ * "((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+
+ *
+ * // . Digits ExponentPart_opt FloatTypeSuffix_opt
+ * "(\\.("+Digits+")("+Exp+")?)|"+
+ *
+ * // Hexadecimal strings
+ * "((" +
+ * // 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt
+ * "(0[xX]" + HexDigits + "(\\.)?)|" +
+ *
+ * // 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt
+ * "(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" +
+ *
+ * ")[pP][+-]?" + Digits + "))" +
+ * "[fFdD]?))" +
+ * "[\\x00-\\x20]*");// Optional trailing "whitespace"
+ *
+ * if (Pattern.matches(fpRegex, myString))
+ * Double.valueOf(myString); // Will not throw NumberFormatException
+ * else {
+ * // Perform suitable alternative action
+ * }
+ * </pre>
+ * </code>
+ *
+ * @param s the string to be parsed.
+ * @return a {@code Double} object holding the value
+ * represented by the {@code String} argument.
+ * @throws NumberFormatException if the string does not contain a
+ * parsable number.
+ */
+ public static Double valueOf(String s) throws NumberFormatException {
+ return new Double(FloatingDecimal.readJavaFormatString(s).doubleValue());
+ }
+
+ /**
+ * Returns a {@code Double} instance representing the specified
+ * {@code double} value.
+ * If a new {@code Double} instance is not required, this method
+ * should generally be used in preference to the constructor
+ * {@link #Double(double)}, as this method is likely to yield
+ * significantly better space and time performance by caching
+ * frequently requested values.
+ *
+ * @param d a double value.
+ * @return a {@code Double} instance representing {@code d}.
+ * @since 1.5
+ */
+ public static Double valueOf(double d) {
+ return new Double(d);
+ }
+
+ /**
+ * Returns a new {@code double} initialized to the value
+ * represented by the specified {@code String}, as performed
+ * by the {@code valueOf} method of class
+ * {@code Double}.
+ *
+ * @param s the string to be parsed.
+ * @return the {@code double} value represented by the string
+ * argument.
+ * @throws NumberFormatException if the string does not contain
+ * a parsable {@code double}.
+ * @see java.lang.Double#valueOf(String)
+ * @since 1.2
+ */
+ public static double parseDouble(String s) throws NumberFormatException {
+ return FloatingDecimal.readJavaFormatString(s).doubleValue();
+ }
+
+ /**
+ * Returns {@code true} if the specified number is a
+ * Not-a-Number (NaN) value, {@code false} otherwise.
+ *
+ * @param v the value to be tested.
+ * @return {@code true} if the value of the argument is NaN;
+ * {@code false} otherwise.
+ */
+ static public boolean isNaN(double v) {
+ return (v != v);
+ }
+
+ /**
+ * Returns {@code true} if the specified number is infinitely
+ * large in magnitude, {@code false} otherwise.
+ *
+ * @param v the value to be tested.
+ * @return {@code true} if the value of the argument is positive
+ * infinity or negative infinity; {@code false} otherwise.
+ */
+ static public boolean isInfinite(double v) {
+ return (v == POSITIVE_INFINITY) || (v == NEGATIVE_INFINITY);
+ }
+
+ /**
+ * The value of the Double.
+ *
+ * @serial
+ */
+ private final double value;
+
+ /**
+ * Constructs a newly allocated {@code Double} object that
+ * represents the primitive {@code double} argument.
+ *
+ * @param value the value to be represented by the {@code Double}.
+ */
+ public Double(double value) {
+ this.value = value;
+ }
+
+ /**
+ * Constructs a newly allocated {@code Double} object that
+ * represents the floating-point value of type {@code double}
+ * represented by the string. The string is converted to a
+ * {@code double} value as if by the {@code valueOf} method.
+ *
+ * @param s a string to be converted to a {@code Double}.
+ * @throws NumberFormatException if the string does not contain a
+ * parsable number.
+ * @see java.lang.Double#valueOf(java.lang.String)
+ */
+ public Double(String s) throws NumberFormatException {
+ // REMIND: this is inefficient
+ this(valueOf(s).doubleValue());
+ }
+
+ /**
+ * Returns {@code true} if this {@code Double} value is
+ * a Not-a-Number (NaN), {@code false} otherwise.
+ *
+ * @return {@code true} if the value represented by this object is
+ * NaN; {@code false} otherwise.
+ */
+ public boolean isNaN() {
+ return isNaN(value);
+ }
+
+ /**
+ * Returns {@code true} if this {@code Double} value is
+ * infinitely large in magnitude, {@code false} otherwise.
+ *
+ * @return {@code true} if the value represented by this object is
+ * positive infinity or negative infinity;
+ * {@code false} otherwise.
+ */
+ public boolean isInfinite() {
+ return isInfinite(value);
+ }
+
+ /**
+ * Returns a string representation of this {@code Double} object.
+ * The primitive {@code double} value represented by this
+ * object is converted to a string exactly as if by the method
+ * {@code toString} of one argument.
+ *
+ * @return a {@code String} representation of this object.
+ * @see java.lang.Double#toString(double)
+ */
+ public String toString() {
+ return String.valueOf(value);
+ }
+
+ /**
+ * Returns the value of this {@code Double} as a {@code byte} (by
+ * casting to a {@code byte}).
+ *
+ * @return the {@code double} value represented by this object
+ * converted to type {@code byte}
+ * @since JDK1.1
+ */
+ public byte byteValue() {
+ return (byte)value;
+ }
+
+ /**
+ * Returns the value of this {@code Double} as a
+ * {@code short} (by casting to a {@code short}).
+ *
+ * @return the {@code double} value represented by this object
+ * converted to type {@code short}
+ * @since JDK1.1
+ */
+ public short shortValue() {
+ return (short)value;
+ }
+
+ /**
+ * Returns the value of this {@code Double} as an
+ * {@code int} (by casting to type {@code int}).
+ *
+ * @return the {@code double} value represented by this object
+ * converted to type {@code int}
+ */
+ public int intValue() {
+ return (int)value;
+ }
+
+ /**
+ * Returns the value of this {@code Double} as a
+ * {@code long} (by casting to type {@code long}).
+ *
+ * @return the {@code double} value represented by this object
+ * converted to type {@code long}
+ */
+ public long longValue() {
+ return (long)value;
+ }
+
+ /**
+ * Returns the {@code float} value of this
+ * {@code Double} object.
+ *
+ * @return the {@code double} value represented by this object
+ * converted to type {@code float}
+ * @since JDK1.0
+ */
+ public float floatValue() {
+ return (float)value;
+ }
+
+ /**
+ * Returns the {@code double} value of this
+ * {@code Double} object.
+ *
+ * @return the {@code double} value represented by this object
+ */
+ public double doubleValue() {
+ return (double)value;
+ }
+
+ /**
+ * Returns a hash code for this {@code Double} object. The
+ * result is the exclusive OR of the two halves of the
+ * {@code long} integer bit representation, exactly as
+ * produced by the method {@link #doubleToLongBits(double)}, of
+ * the primitive {@code double} value represented by this
+ * {@code Double} object. That is, the hash code is the value
+ * of the expression:
+ *
+ * <blockquote>
+ * {@code (int)(v^(v>>>32))}
+ * </blockquote>
+ *
+ * where {@code v} is defined by:
+ *
+ * <blockquote>
+ * {@code long v = Double.doubleToLongBits(this.doubleValue());}
+ * </blockquote>
+ *
+ * @return a {@code hash code} value for this object.
+ */
+ public int hashCode() {
+ long bits = doubleToLongBits(value);
+ return (int)(bits ^ (bits >>> 32));
+ }
+
+ /**
+ * Compares this object against the specified object. The result
+ * is {@code true} if and only if the argument is not
+ * {@code null} and is a {@code Double} object that
+ * represents a {@code double} that has the same value as the
+ * {@code double} represented by this object. For this
+ * purpose, two {@code double} values are considered to be
+ * the same if and only if the method {@link
+ * #doubleToLongBits(double)} returns the identical
+ * {@code long} value when applied to each.
+ *
+ * <p>Note that in most cases, for two instances of class
+ * {@code Double}, {@code d1} and {@code d2}, the
+ * value of {@code d1.equals(d2)} is {@code true} if and
+ * only if
+ *
+ * <blockquote>
+ * {@code d1.doubleValue() == d2.doubleValue()}
+ * </blockquote>
+ *
+ * <p>also has the value {@code true}. However, there are two
+ * exceptions:
+ * <ul>
+ * <li>If {@code d1} and {@code d2} both represent
+ * {@code Double.NaN}, then the {@code equals} method
+ * returns {@code true}, even though
+ * {@code Double.NaN==Double.NaN} has the value
+ * {@code false}.
+ * <li>If {@code d1} represents {@code +0.0} while
+ * {@code d2} represents {@code -0.0}, or vice versa,
+ * the {@code equal} test has the value {@code false},
+ * even though {@code +0.0==-0.0} has the value {@code true}.
+ * </ul>
+ * This definition allows hash tables to operate properly.
+ * @param obj the object to compare with.
+ * @return {@code true} if the objects are the same;
+ * {@code false} otherwise.
+ * @see java.lang.Double#doubleToLongBits(double)
+ */
+ public boolean equals(Object obj) {
+ return (obj instanceof Double)
+ && (doubleToLongBits(((Double)obj).value) ==
+ doubleToLongBits(value));
+ }
+
+ /**
+ * Returns a representation of the specified floating-point value
+ * according to the IEEE 754 floating-point "double
+ * format" bit layout.
+ *
+ * <p>Bit 63 (the bit that is selected by the mask
+ * {@code 0x8000000000000000L}) represents the sign of the
+ * floating-point number. Bits
+ * 62-52 (the bits that are selected by the mask
+ * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0
+ * (the bits that are selected by the mask
+ * {@code 0x000fffffffffffffL}) represent the significand
+ * (sometimes called the mantissa) of the floating-point number.
+ *
+ * <p>If the argument is positive infinity, the result is
+ * {@code 0x7ff0000000000000L}.
+ *
+ * <p>If the argument is negative infinity, the result is
+ * {@code 0xfff0000000000000L}.
+ *
+ * <p>If the argument is NaN, the result is
+ * {@code 0x7ff8000000000000L}.
+ *
+ * <p>In all cases, the result is a {@code long} integer that, when
+ * given to the {@link #longBitsToDouble(long)} method, will produce a
+ * floating-point value the same as the argument to
+ * {@code doubleToLongBits} (except all NaN values are
+ * collapsed to a single "canonical" NaN value).
+ *
+ * @param value a {@code double} precision floating-point number.
+ * @return the bits that represent the floating-point number.
+ */
+ public static long doubleToLongBits(double value) {
+ long result = doubleToRawLongBits(value);
+ // Check for NaN based on values of bit fields, maximum
+ // exponent and nonzero significand.
+ if ( ((result & DoubleConsts.EXP_BIT_MASK) ==
+ DoubleConsts.EXP_BIT_MASK) &&
+ (result & DoubleConsts.SIGNIF_BIT_MASK) != 0L)
+ result = 0x7ff8000000000000L;
+ return result;
+ }
+
+ /**
+ * Returns a representation of the specified floating-point value
+ * according to the IEEE 754 floating-point "double
+ * format" bit layout, preserving Not-a-Number (NaN) values.
+ *
+ * <p>Bit 63 (the bit that is selected by the mask
+ * {@code 0x8000000000000000L}) represents the sign of the
+ * floating-point number. Bits
+ * 62-52 (the bits that are selected by the mask
+ * {@code 0x7ff0000000000000L}) represent the exponent. Bits 51-0
+ * (the bits that are selected by the mask
+ * {@code 0x000fffffffffffffL}) represent the significand
+ * (sometimes called the mantissa) of the floating-point number.
+ *
+ * <p>If the argument is positive infinity, the result is
+ * {@code 0x7ff0000000000000L}.
+ *
+ * <p>If the argument is negative infinity, the result is
+ * {@code 0xfff0000000000000L}.
+ *
+ * <p>If the argument is NaN, the result is the {@code long}
+ * integer representing the actual NaN value. Unlike the
+ * {@code doubleToLongBits} method,
+ * {@code doubleToRawLongBits} does not collapse all the bit
+ * patterns encoding a NaN to a single "canonical" NaN
+ * value.
+ *
+ * <p>In all cases, the result is a {@code long} integer that,
+ * when given to the {@link #longBitsToDouble(long)} method, will
+ * produce a floating-point value the same as the argument to
+ * {@code doubleToRawLongBits}.
+ *
+ * @param value a {@code double} precision floating-point number.
+ * @return the bits that represent the floating-point number.
+ * @since 1.3
+ */
+ public static native long doubleToRawLongBits(double value);
+
+ /**
+ * Returns the {@code double} value corresponding to a given
+ * bit representation.
+ * The argument is considered to be a representation of a
+ * floating-point value according to the IEEE 754 floating-point
+ * "double format" bit layout.
+ *
+ * <p>If the argument is {@code 0x7ff0000000000000L}, the result
+ * is positive infinity.
+ *
+ * <p>If the argument is {@code 0xfff0000000000000L}, the result
+ * is negative infinity.
+ *
+ * <p>If the argument is any value in the range
+ * {@code 0x7ff0000000000001L} through
+ * {@code 0x7fffffffffffffffL} or in the range
+ * {@code 0xfff0000000000001L} through
+ * {@code 0xffffffffffffffffL}, the result is a NaN. No IEEE
+ * 754 floating-point operation provided by Java can distinguish
+ * between two NaN values of the same type with different bit
+ * patterns. Distinct values of NaN are only distinguishable by
+ * use of the {@code Double.doubleToRawLongBits} method.
+ *
+ * <p>In all other cases, let <i>s</i>, <i>e</i>, and <i>m</i> be three
+ * values that can be computed from the argument:
+ *
+ * <blockquote><pre>
+ * int s = ((bits >> 63) == 0) ? 1 : -1;
+ * int e = (int)((bits >> 52) & 0x7ffL);
+ * long m = (e == 0) ?
+ * (bits & 0xfffffffffffffL) << 1 :
+ * (bits & 0xfffffffffffffL) | 0x10000000000000L;
+ * </pre></blockquote>
+ *
+ * Then the floating-point result equals the value of the mathematical
+ * expression <i>s</i>·<i>m</i>·2<sup><i>e</i>-1075</sup>.
+ *
+ * <p>Note that this method may not be able to return a
+ * {@code double} NaN with exactly same bit pattern as the
+ * {@code long} argument. IEEE 754 distinguishes between two
+ * kinds of NaNs, quiet NaNs and <i>signaling NaNs</i>. The
+ * differences between the two kinds of NaN are generally not
+ * visible in Java. Arithmetic operations on signaling NaNs turn
+ * them into quiet NaNs with a different, but often similar, bit
+ * pattern. However, on some processors merely copying a
+ * signaling NaN also performs that conversion. In particular,
+ * copying a signaling NaN to return it to the calling method
+ * may perform this conversion. So {@code longBitsToDouble}
+ * may not be able to return a {@code double} with a
+ * signaling NaN bit pattern. Consequently, for some
+ * {@code long} values,
+ * {@code doubleToRawLongBits(longBitsToDouble(start))} may
+ * <i>not</i> equal {@code start}. Moreover, which
+ * particular bit patterns represent signaling NaNs is platform
+ * dependent; although all NaN bit patterns, quiet or signaling,
+ * must be in the NaN range identified above.
+ *
+ * @param bits any {@code long} integer.
+ * @return the {@code double} floating-point value with the same
+ * bit pattern.
+ */
+ public static native double longBitsToDouble(long bits);
+
+ /**
+ * Compares two {@code Double} objects numerically. There
+ * are two ways in which comparisons performed by this method
+ * differ from those performed by the Java language numerical
+ * comparison operators ({@code <, <=, ==, >=, >})
+ * when applied to primitive {@code double} values:
+ * <ul><li>
+ * {@code Double.NaN} is considered by this method
+ * to be equal to itself and greater than all other
+ * {@code double} values (including
+ * {@code Double.POSITIVE_INFINITY}).
+ * <li>
+ * {@code 0.0d} is considered by this method to be greater
+ * than {@code -0.0d}.
+ * </ul>
+ * This ensures that the <i>natural ordering</i> of
+ * {@code Double} objects imposed by this method is <i>consistent
+ * with equals</i>.
+ *
+ * @param anotherDouble the {@code Double} to be compared.
+ * @return the value {@code 0} if {@code anotherDouble} is
+ * numerically equal to this {@code Double}; a value
+ * less than {@code 0} if this {@code Double}
+ * is numerically less than {@code anotherDouble};
+ * and a value greater than {@code 0} if this
+ * {@code Double} is numerically greater than
+ * {@code anotherDouble}.
+ *
+ * @since 1.2
+ */
+ public int compareTo(Double anotherDouble) {
+ return Double.compare(value, anotherDouble.value);
+ }
+
+ /**
+ * Compares the two specified {@code double} values. The sign
+ * of the integer value returned is the same as that of the
+ * integer that would be returned by the call:
+ * <pre>
+ * new Double(d1).compareTo(new Double(d2))
+ * </pre>
+ *
+ * @param d1 the first {@code double} to compare
+ * @param d2 the second {@code double} to compare
+ * @return the value {@code 0} if {@code d1} is
+ * numerically equal to {@code d2}; a value less than
+ * {@code 0} if {@code d1} is numerically less than
+ * {@code d2}; and a value greater than {@code 0}
+ * if {@code d1} is numerically greater than
+ * {@code d2}.
+ * @since 1.4
+ */
+ public static int compare(double d1, double d2) {
+ if (d1 < d2)
+ return -1; // Neither val is NaN, thisVal is smaller
+ if (d1 > d2)
+ return 1; // Neither val is NaN, thisVal is larger
+
+ long thisBits = Double.doubleToLongBits(d1);
+ long anotherBits = Double.doubleToLongBits(d2);
+
+ return (thisBits == anotherBits ? 0 : // Values are equal
+ (thisBits < anotherBits ? -1 : // (-0.0, 0.0) or (!NaN, NaN)
+ 1)); // (0.0, -0.0) or (NaN, !NaN)
+ }
+
+ /** use serialVersionUID from JDK 1.0.2 for interoperability */
+ private static final long serialVersionUID = -9172774392245257468L;
+}
This was sent by the SourceForge.net collaborative development platform, the world's largest Open Source development site.
|
