*   * @param v the <code>double</code> to compare   * @return whether the argument is (-/+) infinity.   */  public static boolean isInfinite(double v)  {    return v == POSITIVE_INFINITY || v == NEGATIVE_INFINITY;  }  /**   * Return <code>true</code> if the value of this <code>Double</code>   * is the same as <code>NaN</code>, otherwise return <code>false</code>.   *   * @return whether this <code>Double</code> is <code>NaN</code>   */  public boolean isNaN()  {    return isNaN(value);  }  /**   * Return <code>true</code> if the value of this <code>Double</code>   * is the same as <code>NEGATIVE_INFINITY</code> or   * <code>POSITIVE_INFINITY</code>, otherwise return <code>false</code>.   *   * @return whether this <code>Double</code> is (-/+) infinity   */  public boolean isInfinite()  {    return isInfinite(value);  }  /**   * Convert the <code>double</code> value of this <code>Double</code>   * to a <code>String</code>.  This method calls   * <code>Double.toString(double)</code> to do its dirty work.   *   * @return the <code>String</code> representation   * @see #toString(double)   */  public String toString()  {    return toString(value);  }  /**   * Return the value of this <code>Double</code> as a <code>byte</code>.   *   * @return the byte value   * @since 1.1   */  public byte byteValue()  {    return (byte) value;  }  /**   * Return the value of this <code>Double</code> as a <code>short</code>.   *   * @return the short value   * @since 1.1   */  public short shortValue()  {    return (short) value;  }  /**   * Return the value of this <code>Double</code> as an <code>int</code>.   *   * @return the int value   */  public int intValue()  {    return (int) value;  }  /**   * Return the value of this <code>Double</code> as a <code>long</code>.   *   * @return the long value   */  public long longValue()  {    return (long) value;  }  /**   * Return the value of this <code>Double</code> as a <code>float</code>.   *   * @return the float value   */  public float floatValue()  {    return (float) value;  }  /**   * Return the value of this <code>Double</code>.   *   * @return the double value   */  public double doubleValue()  {    return value;  }  /**   * Return a hashcode representing this Object. <code>Double</code>'s hash   * code is calculated by:<br>   * <code>long v = Double.doubleToLongBits(doubleValue());<br>   *    int hash = (int)(v^(v&gt;&gt;32))</code>.   *   * @return this Object's hash code   * @see #doubleToLongBits(double)   */  public int hashCode()  {    long v = doubleToLongBits(value);    return (int) (v ^ (v >>> 32));  }  /**   * Returns <code>true</code> if <code>obj</code> is an instance of   * <code>Double</code> and represents the same double value. Unlike comparing   * two doubles with <code>==</code>, this treats two instances of   * <code>Double.NaN</code> as equal, but treats <code>0.0</code> and   * <code>-0.0</code> as unequal.   *   * <p>Note that <code>d1.equals(d2)</code> is identical to   * <code>doubleToLongBits(d1.doubleValue()) ==   *    doubleToLongBits(d2.doubleValue())</code>.   *   * @param obj the object to compare   * @return whether the objects are semantically equal   */  public boolean equals(Object obj)  {    if (! (obj instanceof Double))      return false;    double d = ((Double) obj).value;    // Avoid call to native method. However, some implementations, like gcj,    // are better off using floatToIntBits(value) == floatToIntBits(f).    // Check common case first, then check NaN and 0.    if (value == d)      return (value != 0) || (1 / value == 1 / d);    return isNaN(value) && isNaN(d);  }  /**   * Convert the double to the IEEE 754 floating-point "double format" bit   * layout. Bit 63 (the most significant) is the sign bit, bits 62-52   * (masked by 0x7ff0000000000000L) represent the exponent, and bits 51-0   * (masked by 0x000fffffffffffffL) are the mantissa. This function   * collapses all versions of NaN to 0x7ff8000000000000L. The result of this   * function can be used as the argument to   * <code>Double.longBitsToDouble(long)</code> to obtain the original   * <code>double</code> value.   *   * @param value the <code>double</code> to convert   * @return the bits of the <code>double</code>   * @see #longBitsToDouble(long)   */  // GCJ LOCAL: We diverge from Classpath for efficiency.  public static native long doubleToLongBits(double value);  // END GCJ LOCAL  /**   * Convert the double to the IEEE 754 floating-point "double format" bit   * layout. Bit 63 (the most significant) is the sign bit, bits 62-52   * (masked by 0x7ff0000000000000L) represent the exponent, and bits 51-0   * (masked by 0x000fffffffffffffL) are the mantissa. This function   * leaves NaN alone, rather than collapsing to a canonical value. The   * result of this function can be used as the argument to   * <code>Double.longBitsToDouble(long)</code> to obtain the original   * <code>double</code> value.   *   * @param value the <code>double</code> to convert   * @return the bits of the <code>double</code>   * @see #longBitsToDouble(long)   */  // GCJ LOCAL: We diverge from Classpath for efficiency.  public static native long doubleToRawLongBits(double value);  // END GCJ LOCAL  /**   * Convert the argument in IEEE 754 floating-point "double format" bit   * layout to the corresponding float. Bit 63 (the most significant) is the   * sign bit, bits 62-52 (masked by 0x7ff0000000000000L) represent the   * exponent, and bits 51-0 (masked by 0x000fffffffffffffL) are the mantissa.   * This function leaves NaN alone, so that you can recover the bit pattern   * with <code>Double.doubleToRawLongBits(double)</code>.   *   * @param bits the bits to convert   * @return the <code>double</code> represented by the bits   * @see #doubleToLongBits(double)   * @see #doubleToRawLongBits(double)   */  // GCJ LOCAL: We diverge from Classpath for efficiency.  public static native double longBitsToDouble(long bits);  // END GCJ LOCAL  /**   * Compare two Doubles numerically by comparing their <code>double</code>   * values. The result is positive if the first is greater, negative if the   * second is greater, and 0 if the two are equal. However, this special   * cases NaN and signed zero as follows: NaN is considered greater than   * all other doubles, including <code>POSITIVE_INFINITY</code>, and positive   * zero is considered greater than negative zero.   *   * @param d the Double to compare   * @return the comparison   * @since 1.2   */  public int compareTo(Double d)  {    return compare(value, d.value);  }  /**   * Behaves like <code>compareTo(Double)</code> unless the Object   * is not an <code>Double</code>.   *   * @param o the object to compare   * @return the comparison   * @throws ClassCastException if the argument is not a <code>Double</code>   * @see #compareTo(Double)   * @see Comparable   * @since 1.2   */  public int compareTo(Object o)  {    return compare(value, ((Double) o).value);  }  /**   * Behaves like <code>new Double(x).compareTo(new Double(y))</code>; in   * other words this compares two doubles, special casing NaN and zero,   * without the overhead of objects.   *   * @param x the first double to compare   * @param y the second double to compare   * @return the comparison   * @since 1.4   */  public static int compare(double x, double y)  {    if (isNaN(x))      return isNaN(y) ? 0 : 1;    if (isNaN(y))      return -1;    // recall that 0.0 == -0.0, so we convert to infinites and try again    if (x == 0 && y == 0)      return (int) (1 / x - 1 / y);    if (x == y)      return 0;    return x > y ? 1 : -1;  }  /**   * Helper method to convert to string.   *   * @param d the double to convert   * @param isFloat true if the conversion is requested by Float (results in   *        fewer digits)   */  // Package visible for use by Float.  static native String toString(double d, boolean isFloat);}