/*

 * Copyright 1996-2009 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;

/**

 * The {@code Short} class wraps a value of primitive type {@code

 * short} in an object.  An object of type {@code Short} contains a

 * single field whose type is {@code short}.

 *

 * <p>In addition, this class provides several methods for converting

 * a {@code short} to a {@code String} and a {@code String} to a

 * {@code short}, as well as other constants and methods useful when

 * dealing with a {@code short}.

 *

 * @author  Nakul Saraiya

 * @author  Joseph D. Darcy

 * @see     java.lang.Number

 * @since   JDK1.1

 */

public final class Short extends Number implements Comparable<Short> {

    /**

     * A constant holding the minimum value a {@code short} can

     * have, -2<sup>15</sup>.

     */

    public static final short   MIN_VALUE = -32768;

    /**

     * A constant holding the maximum value a {@code short} can

     * have, 2<sup>15</sup>-1.

     */

    public static final short   MAX_VALUE = 32767;

    /**

     * The {@code Class} instance representing the primitive type

     * {@code short}.

     */

    public static final Class<Short>    TYPE = (Class<Short>) Class.getPrimitiveClass("short");

    /**

     * Returns a new {@code String} object representing the

     * specified {@code short}. The radix is assumed to be 10.

     *

     * @param s the {@code short} to be converted

     * @return the string representation of the specified {@code short}

     * @see java.lang.Integer#toString(int)

     */

    public static String toString(short s) {

        return Integer.toString((int)s, 10);

    }

    /**

     * Parses the string argument as a signed {@code short} in the

     * radix specified by the second argument. The characters in the

     * string must all be digits, of the specified radix (as

     * determined by whether {@link java.lang.Character#digit(char,

     * int)} returns a nonnegative value) except that the first

     * character may be an ASCII minus sign {@code '-'}

     * (<code>'&#92;u002D'</code>) to indicate a negative value or an

     * ASCII plus sign {@code '+'} (<code>'&#92;u002B'</code>) to

     * indicate a positive value.  The resulting {@code short} value

     * is returned.

     *

     * <p>An exception of type {@code NumberFormatException} is

     * thrown if any of the following situations occurs:

     * <ul>

     * <li> The first argument is {@code null} or is a string of

     * length zero.

     *

     * <li> The radix is either smaller than {@link

     * java.lang.Character#MIN_RADIX} or larger than {@link

     * java.lang.Character#MAX_RADIX}.

     *

     * <li> Any character of the string is not a digit of the

     * specified radix, except that the first character may be a minus

     * sign {@code '-'} (<code>'&#92;u002D'</code>) or plus sign

     * {@code '+'} (<code>'&#92;u002B'</code>) provided that the

     * string is longer than length 1.

     *

     * <li> The value represented by the string is not a value of type

     * {@code short}.

     * </ul>

     *

     * @param s         the {@code String} containing the

     *                  {@code short} representation to be parsed

     * @param radix     the radix to be used while parsing {@code s}

     * @return          the {@code short} represented by the string

     *                  argument in the specified radix.

     * @throws          NumberFormatException If the {@code String}

     *                  does not contain a parsable {@code short}.

     */

    public static short parseShort(String s, int radix)

        throws NumberFormatException {

        int i = Integer.parseInt(s, radix);

        if (i < MIN_VALUE || i > MAX_VALUE)

            throw new NumberFormatException(

                "Value out of range. Value:\"" + s + "\" Radix:" + radix);

        return (short)i;

    }

    /**

     * Parses the string argument as a signed decimal {@code

     * short}. The characters in the string must all be decimal

     * digits, except that the first character may be an ASCII minus

     * sign {@code '-'} (<code>'&#92;u002D'</code>) to indicate a

     * negative value or an ASCII plus sign {@code '+'}

     * (<code>'&#92;u002B'</code>) to indicate a positive value.  The

     * resulting {@code short} value is returned, exactly as if the

     * argument and the radix 10 were given as arguments to the {@link

     * #parseShort(java.lang.String, int)} method.

     *

     * @param s a {@code String} containing the {@code short}

     *          representation to be parsed

     * @return  the {@code short} value represented by the

     *          argument in decimal.

     * @throws  NumberFormatException If the string does not

     *          contain a parsable {@code short}.

     */

    public static short parseShort(String s) throws NumberFormatException {

        return parseShort(s, 10);

    }

    /**

     * Returns a {@code Short} object holding the value

     * extracted from the specified {@code String} when parsed

     * with the radix given by the second argument. The first argument

     * is interpreted as representing a signed {@code short} in

     * the radix specified by the second argument, exactly as if the

     * argument were given to the {@link #parseShort(java.lang.String,

     * int)} method. The result is a {@code Short} object that

     * represents the {@code short} value specified by the string.

     *

     * <p>In other words, this method returns a {@code Short} object

     * equal to the value of:

     *

     * <blockquote>

     *  {@code new Short(Short.parseShort(s, radix))}

     * </blockquote>

     *

     * @param s         the string to be parsed

     * @param radix     the radix to be used in interpreting {@code s}

     * @return          a {@code Short} object holding the value

     *                  represented by the string argument in the

     *                  specified radix.

     * @throws          NumberFormatException If the {@code String} does

     *                  not contain a parsable {@code short}.

     */

    public static Short valueOf(String s, int radix)

        throws NumberFormatException {

        return valueOf(parseShort(s, radix));

    }

    /**

     * Returns a {@code Short} object holding the

     * value given by the specified {@code String}. The argument

     * is interpreted as representing a signed decimal

     * {@code short}, exactly as if the argument were given to

     * the {@link #parseShort(java.lang.String)} method. The result is

     * a {@code Short} object that represents the

     * {@code short} value specified by the string.

     *

     * <p>In other words, this method returns a {@code Short} object

     * equal to the value of:

     *

     * <blockquote>

     *  {@code new Short(Short.parseShort(s))}

     * </blockquote>

     *

     * @param s the string to be parsed

     * @return  a {@code Short} object holding the value

     *          represented by the string argument

     * @throws  NumberFormatException If the {@code String} does

     *          not contain a parsable {@code short}.

     */

    public static Short valueOf(String s) throws NumberFormatException {

        return valueOf(s, 10);

    }

    private static class ShortCache {

        private ShortCache(){}

        static final Short cache[] = new Short[-(-128) + 127 + 1];

        static {

            for(int i = 0; i < cache.length; i++)

                cache[i] = new Short((short)(i - 128));

        }

    }

    /**

     * Returns a {@code Short} instance representing the specified

     * {@code short} value.

     * If a new {@code Short} instance is not required, this method

     * should generally be used in preference to the constructor

     * {@link #Short(short)}, as this method is likely to yield

     * significantly better space and time performance by caching

     * frequently requested values.

     *

     * This method will always cache values in the range -128 to 127,

     * inclusive, and may cache other values outside of this range.

     *

     * @param  s a short value.

     * @return a {@code Short} instance representing {@code s}.

     * @since  1.5

     */

    public static Short valueOf(short s) {

        final int offset = 128;

        int sAsInt = s;

        if (sAsInt >= -128 && sAsInt <= 127) { // must cache

            return ShortCache.cache[sAsInt + offset];

        }

        return new Short(s);

    }

    /**

     * Decodes a {@code String} into a {@code Short}.

     * Accepts decimal, hexadecimal, and octal numbers given by

     * the following grammar:

     *

     * <blockquote>

     * <dl>

     * <dt><i>DecodableString:</i>

     * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>

     * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>

     * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>

     * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>

     * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>

     * <p>

     * <dt><i>Sign:</i>

     * <dd>{@code -}

     * <dd>{@code +}

     * </dl>

     * </blockquote>

     *

     * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>

     * are defined in <a href="http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#48282">&sect;3.10.1</a>

     * of the <a href="http://java.sun.com/docs/books/jls/html/">Java

     * Language Specification</a>.

     *

     * <p>The sequence of characters following an optional

     * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",

     * "{@code #}", or leading zero) is parsed as by the {@code

     * Short.parseShort} method with the indicated radix (10, 16, or

     * 8).  This sequence of characters must represent a positive

     * value or a {@link NumberFormatException} will be thrown.  The

     * result is negated if first character of the specified {@code

     * String} is the minus sign.  No whitespace characters are

     * permitted in the {@code String}.

     *

     * @param     nm the {@code String} to decode.

     * @return    a {@code Short} object holding the {@code short}

     *            value represented by {@code nm}

     * @throws    NumberFormatException  if the {@code String} does not

     *            contain a parsable {@code short}.

     * @see java.lang.Short#parseShort(java.lang.String, int)

     */

    public static Short decode(String nm) throws NumberFormatException {

        int i = Integer.decode(nm);

        if (i < MIN_VALUE || i > MAX_VALUE)

            throw new NumberFormatException(

                    "Value " + i + " out of range from input " + nm);

        return valueOf((short)i);

    }

    /**

     * The value of the {@code Short}.

     *

     * @serial

     */

    private final short value;

    /**

     * Constructs a newly allocated {@code Short} object that

     * represents the specified {@code short} value.

     *

     * @param value     the value to be represented by the

     *                  {@code Short}.

     */

    public Short(short value) {

        this.value = value;

    }

    /**

     * Constructs a newly allocated {@code Short} object that

     * represents the {@code short} value indicated by the

     * {@code String} parameter. The string is converted to a

     * {@code short} value in exactly the manner used by the

     * {@code parseShort} method for radix 10.

     *

     * @param s the {@code String} to be converted to a

     *          {@code Short}

     * @throws  NumberFormatException If the {@code String}

     *          does not contain a parsable {@code short}.

     * @see     java.lang.Short#parseShort(java.lang.String, int)

     */

    public Short(String s) throws NumberFormatException {

        this.value = parseShort(s, 10);

    }

    /**

     * Returns the value of this {@code Short} as a

     * {@code byte}.

     */

    public byte byteValue() {

        return (byte)value;

    }

    /**

     * Returns the value of this {@code Short} as a

     * {@code short}.

     */

    public short shortValue() {

        return value;

    }

    /**

     * Returns the value of this {@code Short} as an

     * {@code int}.

     */

    public int intValue() {

        return (int)value;

    }

    /**

     * Returns the value of this {@code Short} as a

     * {@code long}.

     */

    public long longValue() {

        return (long)value;

    }

    /**

     * Returns the value of this {@code Short} as a

     * {@code float}.

     */

    public float floatValue() {

        return (float)value;

    }

    /**

     * Returns the value of this {@code Short} as a

     * {@code double}.

     */

    public double doubleValue() {

        return (double)value;

    }

    /**

     * Returns a {@code String} object representing this

     * {@code Short}'s value.  The value is converted to signed

     * decimal representation and returned as a string, exactly as if

     * the {@code short} value were given as an argument to the

     * {@link java.lang.Short#toString(short)} method.

     *

     * @return  a string representation of the value of this object in

     *          base 10.

     */

    public String toString() {

        return Integer.toString((int)value);

    }

    /**

     * Returns a hash code for this {@code Short}; equal to the result

     * of invoking {@code intValue()}.

     *

     * @return a hash code value for this {@code Short}

     */

    public int hashCode() {

        return (int)value;

    }

    /**

     * Compares this object to the specified object.  The result is

     * {@code true} if and only if the argument is not

     * {@code null} and is a {@code Short} object that

     * contains the same {@code short} value as this object.

     *

     * @param obj       the object to compare with

     * @return          {@code true} if the objects are the same;

     *                  {@code false} otherwise.

     */

    public boolean equals(Object obj) {

        if (obj instanceof Short) {

            return value == ((Short)obj).shortValue();

        }

        return false;

    }

    /**

     * Compares two {@code Short} objects numerically.

     *

     * @param   anotherShort   the {@code Short} to be compared.

     * @return  the value {@code 0} if this {@code Short} is

     *          equal to the argument {@code Short}; a value less than

     *          {@code 0} if this {@code Short} is numerically less

     *          than the argument {@code Short}; and a value greater than

     *           {@code 0} if this {@code Short} is numerically

     *           greater than the argument {@code Short} (signed

     *           comparison).

     * @since   1.2

     */

    public int compareTo(Short anotherShort) {

        return compare(this.value, anotherShort.value);

    }

    /**

     * Compares two {@code short} values numerically.

     * The value returned is identical to what would be returned by:

     * <pre>

     *    Short.valueOf(x).compareTo(Short.valueOf(y))

     * </pre>

     *

     * @param  x the first {@code short} to compare

     * @param  y the second {@code short} to compare

     * @return the value {@code 0} if {@code x == y};

     *         a value less than {@code 0} if {@code x < y}; and

     *         a value greater than {@code 0} if {@code x > y}

     * @since 1.7

     */

    public static int compare(short x, short y) {

        return x - y;

    }

    /**

     * The number of bits used to represent a {@code short} value in two's

     * complement binary form.

     * @since 1.5

     */

    public static final int SIZE = 16;

    /**

     * Returns the value obtained by reversing the order of the bytes in the

     * two's complement representation of the specified {@code short} value.

     *

     * @return the value obtained by reversing (or, equivalently, swapping)

     *     the bytes in the specified {@code short} value.

     * @since 1.5

     */

    public static short reverseBytes(short i) {

        return (short) (((i & 0xFF00) >> 8) | (i << 8));

    }

    /** use serialVersionUID from JDK 1.1. for interoperability */

    private static final long serialVersionUID = 7515723908773894738L;

}