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The Short.java Java example source code
/*
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.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.
*/
public static final short MIN_VALUE = -32768;
/**
* A constant holding the maximum value a {@code short} can
* have, 2<sup>15-1.
*/
public static final short MAX_VALUE = 32767;
/**
* The {@code Class} instance representing the primitive type
* {@code short}.
*/
@SuppressWarnings("unchecked")
public static final Class<Short> TYPE = (Class) 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 '\u005Cu002D'}) to indicate a negative value or an
* ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) 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 '\u005Cu002D'}) or plus sign
* {@code '+'} ({@code '\u005Cu002B'}) 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 '\u005Cu002D'}) to indicate a
* negative value or an ASCII plus sign {@code '+'}
* ({@code '\u005Cu002B'}) 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>DecodableString:
* <dd>Signopt DecimalNumeral
* <dd>Signopt {@code 0x} HexDigits
* <dd>Signopt {@code 0X} HexDigits
* <dd>Signopt {@code #} HexDigits
* <dd>Signopt {@code 0} OctalDigits
*
* <dt>Sign:
* <dd>{@code -}
* <dd>{@code +}
* </dl>
* </blockquote>
*
* <i>DecimalNumeral, HexDigits, and OctalDigits
* are as defined in section 3.10.1 of
* <cite>The Java™ Language Specification,
* except that underscores are not accepted between digits.
*
* <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} after
* a narrowing primitive conversion.
* @jls 5.1.3 Narrowing Primitive Conversions
*/
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} after
* a widening primitive conversion.
* @jls 5.1.2 Widening Primitive Conversions
*/
public int intValue() {
return (int)value;
}
/**
* Returns the value of this {@code Short} as a {@code long} after
* a widening primitive conversion.
* @jls 5.1.2 Widening Primitive Conversions
*/
public long longValue() {
return (long)value;
}
/**
* Returns the value of this {@code Short} as a {@code float}
* after a widening primitive conversion.
* @jls 5.1.2 Widening Primitive Conversions
*/
public float floatValue() {
return (float)value;
}
/**
* Returns the value of this {@code Short} as a {@code double}
* after a widening primitive conversion.
* @jls 5.1.2 Widening Primitive Conversions
*/
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}
*/
@Override
public int hashCode() {
return Short.hashCode(value);
}
/**
* Returns a hash code for a {@code short} value; compatible with
* {@code Short.hashCode()}.
*
* @param value the value to hash
* @return a hash code value for a {@code short} value.
* @since 1.8
*/
public static int hashCode(short value) {
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;
/**
* The number of bytes used to represent a {@code short} value in two's
* complement binary form.
*
* @since 1.8
*/
public static final int BYTES = SIZE / Byte.SIZE;
/**
* Returns the value obtained by reversing the order of the bytes in the
* two's complement representation of the specified {@code short} value.
*
* @param i the value whose bytes are to be reversed
* @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));
}
/**
* Converts the argument to an {@code int} by an unsigned
* conversion. In an unsigned conversion to an {@code int}, the
* high-order 16 bits of the {@code int} are zero and the
* low-order 16 bits are equal to the bits of the {@code short} argument.
*
* Consequently, zero and positive {@code short} values are mapped
* to a numerically equal {@code int} value and negative {@code
* short} values are mapped to an {@code int} value equal to the
* input plus 2<sup>16.
*
* @param x the value to convert to an unsigned {@code int}
* @return the argument converted to {@code int} by an unsigned
* conversion
* @since 1.8
*/
public static int toUnsignedInt(short x) {
return ((int) x) & 0xffff;
}
/**
* Converts the argument to a {@code long} by an unsigned
* conversion. In an unsigned conversion to a {@code long}, the
* high-order 48 bits of the {@code long} are zero and the
* low-order 16 bits are equal to the bits of the {@code short} argument.
*
* Consequently, zero and positive {@code short} values are mapped
* to a numerically equal {@code long} value and negative {@code
* short} values are mapped to a {@code long} value equal to the
* input plus 2<sup>16.
*
* @param x the value to convert to an unsigned {@code long}
* @return the argument converted to {@code long} by an unsigned
* conversion
* @since 1.8
*/
public static long toUnsignedLong(short x) {
return ((long) x) & 0xffffL;
}
/** use serialVersionUID from JDK 1.1. for interoperability */
private static final long serialVersionUID = 7515723908773894738L;
}
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