/* * * * Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER * * This program 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. * * This program 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 at /legal/license.txt). * * 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 or visit www.sun.com if you need additional * information or have any questions. */ package java.lang; import com.jopdesign.sys.Native; /** * The Double class wraps a value of the primitive type * <code>double</code> in an object. An object of type * <code>Double</code> contains a single field whose type is * <code>double</code>. * <p> * In addition, this class provides several methods for converting a * <code>double</code> to a <code>String</code> and a * <code>String</code> to a <code>double</code>, as well as other * constants and methods useful when dealing with a * <code>double</code>. * * @version 12/17/01 (CLDC 1.1) * @since JDK1.0, CLDC 1.1 */ public final class Double { /** * The positive infinity of type <code>double</code>. * It is equal to the value returned by * <code>Double.longBitsToDouble(0x7ff0000000000000L)</code>. */ public static final double POSITIVE_INFINITY = 1.0 / 0.0; /** * The negative infinity of type <code>double</code>. * It is equal to the value returned by * <code>Double.longBitsToDouble(0xfff0000000000000L)</code>. */ public static final double NEGATIVE_INFINITY = -1.0 / 0.0; /** * A Not-a-Number (NaN) value of type <code>double</code>. * It is equal to the value returned by * <code>Double.longBitsToDouble(0x7ff8000000000000L)</code>. */ public static final double NaN = 0.0d / 0.0; /** * The largest positive finite value of type <code>double</code>. * It is equal to the value returned by * <blockquote><pre> * <code>Double.longBitsToDouble(0x7fefffffffffffffL)</code> * </pre></blockquote> */ public static final double MAX_VALUE = 1.79769313486231570e+308; /** * The smallest positive value of type <code>double</code>. * It is equal to the value returned by * <code>Double.longBitsToDouble(0x1L)</code>. */ public static final double MIN_VALUE = 4.94065645841246544e-324; /** * Creates a string representation of the <code>double</code> * argument. All characters mentioned below are ASCII characters. * <ul> * <li>If the argument is NaN, the result is the string "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>' * ('<code>\u002d</code>'); if the sign is positive, no sign character * appears in the result. As for the magnitude <i>m</i>: * <li>If <i>m</i> is infinity, it is represented by the characters * <code>"Infinity"</code>; thus, positive infinity produces the result * <code>"Infinity"</code> and negative infinity produces the result * <code>"-Infinity"</code>. * <li>If <i>m</i> is zero, it is represented by the characters * <code>"0.0"</code>; thus, negative zero produces the result * <code>"-0.0"</code> and positive zero produces the result * <code>"0.0"</code>. * <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> (<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 not less than * 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>n</sup><=<i>m</i><10<sup>n+1</sup>; then let <i>a</i> be * the mathematically exact quotient of <i>m</i> and 10<sup>n</sup> so * that 1<=<i>a</i><10. The magnitude is then represented as the * integer part of <i>a</i>, as a single decimal digit, followed * by <code>'.'</code> (<code>\u002E</code>), followed by decimal digits * representing the fractional part of <i>a</i>, followed by the letter * <code>'E'</code> (<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><p> * 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</code>. 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</code> value nearest * to <i>x</i>; or if two <code>double</code> 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</code>. * * @param d the <code>double</code> to be converted. * @return a string representation of the argument. */ public static String toString(double d){ return new FloatingDecimal(d).toJavaFormatString(); } /** * Returns a new <code>Double</code> object initialized to the value * represented by the specified string. The string <code>s</code> is * interpreted as the representation of a floating-point value and a * <code>Double</code> object representing that value is created and * returned. * <p> * If <code>s</code> is <code>null</code>, then a * <code>NullPointerException</code> is thrown. * <p> * Leading and trailing whitespace characters in s are ignored. The rest * of <code>s</code> should constitute a <i>FloatValue</i> as described * by the lexical rule: * <blockquote><pre><i> * FloatValue: * * Sign<sub>opt</sub> FloatingPointLiteral * </i></pre></blockquote> * where <i>Sign</i> and <i>FloatingPointLiteral</i> are as defined in * Section 3.10.2 of the <a href="http://java.sun.com/docs/books/jls/html/">Java * Language Specification</a>. If it does not have the form of a * <i>FloatValue</i>, then a <code>NumberFormatException</code> is * thrown. Otherwise, it is regarded as representing an exact decimal * value in the usual "computerized scientific notation"; this exact * decimal value is then conceptually converted to an "infinitely * precise" binary value that is then rounded to type <code>double</code> * by the usual round-to-nearest rule of IEEE 754 floating-point * arithmetic. Finally, a new object of class <code>Double</code> is * created to represent the <code>double</code> value. * * @param s the string to be parsed. * @return a newly constructed <code>Double</code> initialized to the * value represented by the string argument. * @exception 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 new double initialized to the value represented by the * specified <code>String</code>, as performed by the <code>valueOf</code> * method of class <code>Double</code>. * * @param s the string to be parsed. * @return the double value represented by the string argument. * @exception NumberFormatException if the string does not contain a * parsable double. * @see java.lang.Double#valueOf(String) * @since JDK1.2 */ public static double parseDouble(String s) throws NumberFormatException { return FloatingDecimal.readJavaFormatString(s).doubleValue(); } /** * Returns true if the specified number is the special Not-a-Number (NaN) * value. * * @param v the value to be tested. * @return <code>true</code> if the value of the argument is NaN; * <code>false</code> otherwise. */ static public boolean isNaN(double v) { return (v != v); } /** * Returns true if the specified number is infinitely large in magnitude. * * @param v the value to be tested. * @return <code>true</code> if the value of the argument is positive * infinity or negative infinity; <code>false</code> otherwise. */ static public boolean isInfinite(double v) { return (v == POSITIVE_INFINITY) || (v == NEGATIVE_INFINITY); } /** * The value of the Double. */ private double value; /** * Constructs a newly allocated <code>Double</code> object that * represents the primitive <code>double</code> argument. * * @param value the value to be represented by the <code>Double</code>. */ public Double(double value) { this.value = value; } /** * Constructs a newly allocated <code>Double</code> object that * represents the floating- point value of type <code>double</code> * represented by the string. The string is converted to a * <code>double</code> value as if by the <code>valueOf</code> method. * * @param s a string to be converted to a <code>Double</code>. * @exception NumberFormatException if the string does not contain a * parsable number. * @see java.lang.Double#valueOf(java.lang.String) */ /* REMOVED from CLDC public Double(String s) throws NumberFormatException { // IMPL_NOTE: this is inefficient this(valueOf(s).doubleValue()); } */ /** * Returns true if this Double value is the special Not-a-Number (NaN) * value. * * @return <code>true</code> if the value represented by this object is * NaN; <code>false</code> otherwise. */ public boolean isNaN() { return isNaN(value); } /** * Returns true if this Double value is infinitely large in magnitude. * * @return <code>true</code> if the value represented by this object is * positive infinity or negative infinity; * <code>false</code> otherwise. */ public boolean isInfinite() { return isInfinite(value); } /** * Returns a String representation of this Double object. * The primitive <code>double</code> value represented by this * object is converted to a string exactly as if by the method * <code>toString</code> of one argument. * * @return a <code>String</code> representation of this object. * @see java.lang.Double#toString(double) */ public String toString() { return new FloatingDecimal(value).toJavaFormatString(); } /** * Returns the value of this Double as a byte (by casting to a byte). * * @since JDK1.1 */ public byte byteValue() { return (byte)value; } /** * Returns the value of this Double as a short (by casting to a short). * * @since JDK1.1 */ public short shortValue() { return (short)value; } /** * Returns the integer value of this Double (by casting to an int). * * @return the <code>double</code> value represented by this object is * converted to type <code>int</code> and the result of the * conversion is returned. */ public int intValue() { return (int)value; } /** * Returns the long value of this Double (by casting to a long). * * @return the <code>double</code> value represented by this object is * converted to type <code>long</code> and the result of the * conversion is returned. */ public long longValue() { return (long)value; } /** * Returns the float value of this Double. * * @return the <code>double</code> value represented by this object is * converted to type <code>float</code> and the result of the * conversion is returned. * @since JDK1.0 */ public float floatValue() { return (float)value; } /** * Returns the double value of this Double. * * @return the <code>double</code> value represented by this object. */ public double doubleValue() { return (double)value; } /** * Returns a hashcode for this <code>Double</code> object. The result * is the exclusive OR of the two halves of the long integer bit * representation, exactly as produced by the method * {@link #doubleToLongBits(double)}, of the primitive * <code>double</code> value represented by this <code>Double</code> * object. That is, the hashcode is the value of the expression: * <blockquote><pre> * (int)(v^(v>>>32)) * </pre></blockquote> * where <code>v</code> is defined by: * <blockquote><pre> * long v = Double.doubleToLongBits(this.doubleValue()); * </pre></blockquote> * * @return a <code>hash code</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</code> if and only if the argument is * not <code>null</code> and is a <code>Double</code> object that * represents a double that has the identical bit pattern to the bit * pattern of the double represented by this object. For this purpose, * two <code>double</code> values are considered to be the same if and * only if the method {@link #doubleToLongBits(double)} returns the same * long value when applied to each. * <p> * Note that in most cases, for two instances of class * <code>Double</code>, <code>d1</code> and <code>d2</code>, the * value of <code>d1.equals(d2)</code> is <code>true</code> if and * only if * <blockquote><pre> * d1.doubleValue() == d2.doubleValue() * </pre></blockquote> * <p> * also has the value <code>true</code>. However, there are two * exceptions: * <ul> * <li>If <code>d1</code> and <code>d2</code> both represent * <code>Double.NaN</code>, then the <code>equals</code> method * returns <code>true</code>, even though * <code>Double.NaN==Double.NaN</code> has the value * <code>false</code>. * <li>If <code>d1</code> represents <code>+0.0</code> while * <code>d2</code> represents <code>-0.0</code>, or vice versa, * the <code>equals</code> test has the value <code>false</code>, * even though <code>+0.0==-0.0</code> has the value <code>true</code>. * This allows hashtables to operate properly. * </ul> * * @param obj the object to compare with. * @return <code>true</code> if the objects are the same; * <code>false</code> otherwise. */ 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</code>) represents the sign of the * floating-point number. Bits * 62-52 (the bits that are selected by the mask * <code>0x7ff0000000000000L</code>) represent the exponent. Bits 51-0 * (the bits that are selected by the mask * <code>0x000fffffffffffffL</code>) represent the significand * (sometimes called the mantissa) of the floating-point number. * <p> * If the argument is positive infinity, the result is * <code>0x7ff0000000000000L</code>. * <p> * If the argument is negative infinity, the result is * <code>0xfff0000000000000L</code>. * <p> * If the argument is NaN, the result is * <code>0x7ff8000000000000L</code>. * <p> * In all cases, the result is a <code>long</code> integer that, when * given to the {@link #longBitsToDouble(long)} method, will produce a * floating-point value equal to the argument to * <code>doubleToLongBits</code>. * * @param value a double precision floating-point number. * @return the bits that represent the floating-point number. */ // public static native long doubleToLongBits(double value); public static long doubleToLongBits(double value) { long v = Native.toLong(value); if ((v & 0x7fffffffffffffffL) > 0x7ff0000000000000L) { return 0x7ff8000000000000L; } return v; } /** * 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</code>) represents the sign of the * floating-point number. Bits * 62-52 (the bits that are selected by the mask * <code>0x7ff0000000000000L</code>) represent the exponent. Bits 51-0 * (the bits that are selected by the mask * <code>0x000fffffffffffffL</code>) represent the significand * (sometimes called the mantissa) of the floating-point number. * <p> * If the argument is positive infinity, the result is * <code>0x7ff0000000000000L</code>. * <p> * If the argument is negative infinity, the result is * <code>0xfff0000000000000L</code>. * <p> * If the argument is NaN, the result is the <code>long</code> integer * representing the actual NaN value. Unlike the <code>doubleToLongBits</code> * method, <code>doubleToRawLongBits</code> does not collapse NaN values. * <p> * In all cases, the result is a <code>long</code> integer that, when * given to the {@link #longBitsToDouble(long)} method, will produce a * floating-point value equal to the argument to * <code>doubleToRawLongBits</code>. * * @param value a double precision floating-point number. * @return the bits that represent the floating-point number. */ /* REMOVED from CLDC public static native long doubleToRawLongBits(double value); */ /** * Returns the double-float 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 precision" bit layout. That floating-point * value is returned as the result. * <p> * If the argument is <code>0x7ff0000000000000L</code>, the result * is positive infinity. * <p> * If the argument is <code>0xfff0000000000000L</code>, the result * is negative infinity. * <p> * If the argument is any value in the range * <code>0x7ff0000000000001L</code> through * <code>0x7fffffffffffffffL</code> or in the range * <code>0xfff0000000000001L</code> through * <code>0xffffffffffffffffL</code>, the result is NaN. All IEEE 754 * NaN values of type <code>double</code> are, in effect, lumped together * by the Java programming language into a single value called NaN. * <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>e-1075</sup>. * * @param bits any <code>long</code> integer. * @return the <code>double</code> floating-point value with the same * bit pattern. */ // public static native double longBitsToDouble(long bits); public static double longBitsToDouble(long bits) { return Native.toDouble(bits); } /** * Compares two Doubles numerically. There are two ways in which * comparisons performed by this method differ from those performed * by the Java language numerical comparison operators (<code><, <=, * ==, >= ></code>) when applied to primitive doubles: * <ul><li> * <code>Double.NaN</code> is considered by this method to be * equal to itself and greater than all other double values * (including <code>Double.POSITIVE_INFINITY</code>). * <li> * <code>0.0d</code> is considered by this method to be greater * than <code>-0.0d</code>. * </ul> * This ensures that Double.compareTo(Object) (which inherits its behavior * from this method) obeys the general contract for Comparable.compareTo, * and that the <i>natural order</i> on Doubles is <i>total</i>. * * @param anotherDouble the <code>Double</code> to be compared. * @return the value <code>0</code> if <code>anotherDouble</code> is * numerically equal to this Double; a value less than * <code>0</code> if this Double is numerically less than * <code>anotherDouble</code>; and a value greater than * <code>0</code> if this Double is numerically greater than * <code>anotherDouble</code>. * * @since JDK1.2 * @see Comparable#compareTo(Object) */ /* REMOVED from CLDC public int compareTo(Double anotherDouble) { double thisVal = value; double anotherVal = anotherDouble.value; if (thisVal < anotherVal) return -1; // Neither val is NaN, thisVal is smaller if (thisVal > anotherVal) return 1; // Neither val is NaN, thisVal is larger long thisBits = Double.doubleToLongBits(thisVal); long anotherBits = Double.doubleToLongBits(anotherVal); 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) } */ /** * Compares this Double to another Object. If the Object is a Double, * this function behaves like <code>compareTo(Double)</code>. Otherwise, * it throws a <code>ClassCastException</code> (as Doubles are comparable * only to other Doubles). * * @param o the <code>Object</code> to be compared. * @return the value <code>0</code> if the argument is a Double * numerically equal to this Double; a value less than * <code>0</code> if the argument is a Double numerically * greater than this Double; and a value greater than * <code>0</code> if the argument is a Double numerically * less than this Double. * @exception <code>ClassCastException</code> if the argument is not a * <code>Double</code>. * @see java.lang.Comparable * @since JDK1.2 */ /* REMOVED from CLDC public int compareTo(Object o) { return compareTo((Double)o); } */ }