1 /*
2 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.lang;
27
28 import jdk.internal.HotSpotIntrinsicCandidate;
29
30 /**
31 * The {@code Short} class wraps a value of primitive type {@code
32 * short} in an object. An object of type {@code Short} contains a
33 * single field whose type is {@code short}.
34 *
35 * <p>In addition, this class provides several methods for converting
36 * a {@code short} to a {@code String} and a {@code String} to a
37 * {@code short}, as well as other constants and methods useful when
38 * dealing with a {@code short}.
39 *
40 * @author Nakul Saraiya
41 * @author Joseph D. Darcy
42 * @see java.lang.Number
43 * @since 1.1
44 */
45 public final class Short extends Number implements Comparable<Short> {
46
47 /**
48 * A constant holding the minimum value a {@code short} can
49 * have, -2<sup>15</sup>.
50 */
51 public static final short MIN_VALUE = -32768;
52
53 /**
54 * A constant holding the maximum value a {@code short} can
55 * have, 2<sup>15</sup>-1.
56 */
57 public static final short MAX_VALUE = 32767;
58
59 /**
60 * The {@code Class} instance representing the primitive type
61 * {@code short}.
62 */
63 @SuppressWarnings("unchecked")
64 public static final Class<Short> TYPE = (Class<Short>) Class.getPrimitiveClass("short");
65
66 private static final Short ZERO = new Short((short)0);
67
68 /**
69 * Returns a new {@code String} object representing the
70 * specified {@code short}. The radix is assumed to be 10.
71 *
72 * @param s the {@code short} to be converted
73 * @return the string representation of the specified {@code short}
74 * @see java.lang.Integer#toString(int)
75 */
76 public static String toString(short s) {
77 return Integer.toString((int)s, 10);
78 }
79
80 /**
81 * Parses the string argument as a signed {@code short} in the
82 * radix specified by the second argument. The characters in the
83 * string must all be digits, of the specified radix (as
84 * determined by whether {@link java.lang.Character#digit(char,
85 * int)} returns a nonnegative value) except that the first
86 * character may be an ASCII minus sign {@code '-'}
87 * ({@code '\u005Cu002D'}) to indicate a negative value or an
88 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
89 * indicate a positive value. The resulting {@code short} value
90 * is returned.
91 *
92 * <p>An exception of type {@code NumberFormatException} is
93 * thrown if any of the following situations occurs:
94 * <ul>
95 * <li> The first argument is {@code null} or is a string of
96 * length zero.
97 *
98 * <li> The radix is either smaller than {@link
99 * java.lang.Character#MIN_RADIX} or larger than {@link
100 * java.lang.Character#MAX_RADIX}.
101 *
102 * <li> Any character of the string is not a digit of the
103 * specified radix, except that the first character may be a minus
104 * sign {@code '-'} ({@code '\u005Cu002D'}) or plus sign
105 * {@code '+'} ({@code '\u005Cu002B'}) provided that the
106 * string is longer than length 1.
107 *
108 * <li> The value represented by the string is not a value of type
109 * {@code short}.
110 * </ul>
111 *
112 * @param s the {@code String} containing the
113 * {@code short} representation to be parsed
114 * @param radix the radix to be used while parsing {@code s}
115 * @return the {@code short} represented by the string
116 * argument in the specified radix.
117 * @throws NumberFormatException If the {@code String}
118 * does not contain a parsable {@code short}.
119 */
120 public static short parseShort(String s, int radix)
121 throws NumberFormatException {
122 int i = Integer.parseInt(s, radix);
123 if (i < MIN_VALUE || i > MAX_VALUE)
124 throw new NumberFormatException(
125 "Value out of range. Value:\"" + s + "\" Radix:" + radix);
126 return (short)i;
127 }
128
129 /**
130 * Parses the string argument as a signed decimal {@code
131 * short}. The characters in the string must all be decimal
132 * digits, except that the first character may be an ASCII minus
133 * sign {@code '-'} ({@code '\u005Cu002D'}) to indicate a
134 * negative value or an ASCII plus sign {@code '+'}
135 * ({@code '\u005Cu002B'}) to indicate a positive value. The
136 * resulting {@code short} value is returned, exactly as if the
137 * argument and the radix 10 were given as arguments to the {@link
138 * #parseShort(java.lang.String, int)} method.
139 *
140 * @param s a {@code String} containing the {@code short}
141 * representation to be parsed
142 * @return the {@code short} value represented by the
143 * argument in decimal.
144 * @throws NumberFormatException If the string does not
145 * contain a parsable {@code short}.
146 */
147 public static short parseShort(String s) throws NumberFormatException {
148 return parseShort(s, 10);
149 }
150
151 /**
152 * Returns a {@code Short} object holding the value
153 * extracted from the specified {@code String} when parsed
154 * with the radix given by the second argument. The first argument
155 * is interpreted as representing a signed {@code short} in
156 * the radix specified by the second argument, exactly as if the
157 * argument were given to the {@link #parseShort(java.lang.String,
158 * int)} method. The result is a {@code Short} object that
159 * represents the {@code short} value specified by the string.
160 *
161 * <p>In other words, this method returns a {@code Short} object
162 * equal to the value of:
163 *
164 * <blockquote>
165 * {@code new Short(Short.parseShort(s, radix))}
166 * </blockquote>
167 *
168 * @param s the string to be parsed
169 * @param radix the radix to be used in interpreting {@code s}
170 * @return a {@code Short} object holding the value
171 * represented by the string argument in the
172 * specified radix.
173 * @throws NumberFormatException If the {@code String} does
174 * not contain a parsable {@code short}.
175 */
176 public static Short valueOf(String s, int radix)
177 throws NumberFormatException {
178 return valueOf(parseShort(s, radix));
179 }
180
181 /**
182 * Returns a {@code Short} object holding the
183 * value given by the specified {@code String}. The argument
184 * is interpreted as representing a signed decimal
185 * {@code short}, exactly as if the argument were given to
186 * the {@link #parseShort(java.lang.String)} method. The result is
187 * a {@code Short} object that represents the
188 * {@code short} value specified by the string.
189 *
190 * <p>In other words, this method returns a {@code Short} object
191 * equal to the value of:
192 *
193 * <blockquote>
194 * {@code new Short(Short.parseShort(s))}
195 * </blockquote>
196 *
197 * @param s the string to be parsed
198 * @return a {@code Short} object holding the value
199 * represented by the string argument
200 * @throws NumberFormatException If the {@code String} does
201 * not contain a parsable {@code short}.
202 */
203 public static Short valueOf(String s) throws NumberFormatException {
204 return valueOf(s, 10);
205 }
206
207 private static class ShortCache {
208 private ShortCache(){}
209
210 static final Short cache[] = new Short[-(-128) + 127 + 1];
211
212 static {
213 for(int i = 0; i < cache.length; i++) {
214 int val = i - 128;
215 cache[i] = (val == 0) ? ZERO : new Short((short)val);
216 }
217 }
218 }
219
220 /**
221 * Returns a {@code Short} instance representing the specified
222 * {@code short} value.
223 * If a new {@code Short} instance is not required, this method
224 * should generally be used in preference to the constructor
225 * {@link #Short(short)}, as this method is likely to yield
226 * significantly better space and time performance by caching
227 * frequently requested values.
228 *
229 * This method will always cache values in the range -128 to 127,
230 * inclusive, and may cache other values outside of this range.
231 *
232 * @param s a short value.
233 * @return a {@code Short} instance representing {@code s}.
234 * @since 1.5
235 */
236 @HotSpotIntrinsicCandidate
237 public static Short valueOf(short s) {
238 final int offset = 128;
239 int sAsInt = s;
240 if (sAsInt >= -128 && sAsInt <= 127) { // must cache
241 return ShortCache.cache[sAsInt + offset];
242 }
243 return new Short(s);
244 }
245
246 /**
247 * Decodes a {@code String} into a {@code Short}.
248 * Accepts decimal, hexadecimal, and octal numbers given by
249 * the following grammar:
250 *
251 * <blockquote>
252 * <dl>
253 * <dt><i>DecodableString:</i>
254 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
255 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
256 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
257 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
258 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
259 *
260 * <dt><i>Sign:</i>
261 * <dd>{@code -}
262 * <dd>{@code +}
263 * </dl>
264 * </blockquote>
265 *
266 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
267 * are as defined in section 3.10.1 of
268 * <cite>The Java™ Language Specification</cite>,
269 * except that underscores are not accepted between digits.
270 *
271 * <p>The sequence of characters following an optional
272 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
273 * "{@code #}", or leading zero) is parsed as by the {@code
274 * Short.parseShort} method with the indicated radix (10, 16, or
275 * 8). This sequence of characters must represent a positive
276 * value or a {@link NumberFormatException} will be thrown. The
277 * result is negated if first character of the specified {@code
278 * String} is the minus sign. No whitespace characters are
279 * permitted in the {@code String}.
280 *
281 * @param nm the {@code String} to decode.
282 * @return a {@code Short} object holding the {@code short}
283 * value represented by {@code nm}
284 * @throws NumberFormatException if the {@code String} does not
285 * contain a parsable {@code short}.
286 * @see java.lang.Short#parseShort(java.lang.String, int)
287 */
288 public static Short decode(String nm) throws NumberFormatException {
289 int i = Integer.decode(nm);
290 if (i < MIN_VALUE || i > MAX_VALUE)
291 throw new NumberFormatException(
292 "Value " + i + " out of range from input " + nm);
293 return valueOf((short)i);
294 }
295
296 /**
297 * The value of the {@code Short}.
298 *
299 * @serial
300 */
301 private final short value;
302
303 /**
304 * Constructs a newly allocated {@code Short} object that
305 * represents the specified {@code short} value.
306 *
307 * @param value the value to be represented by the
308 * {@code Short}.
309 */
310 public Short(short value) {
311 this.value = value;
312 }
313
314 /**
315 * Constructs a newly allocated {@code Short} object that
316 * represents the {@code short} value indicated by the
317 * {@code String} parameter. The string is converted to a
318 * {@code short} value in exactly the manner used by the
319 * {@code parseShort} method for radix 10.
320 *
321 * @param s the {@code String} to be converted to a
322 * {@code Short}
323 * @throws NumberFormatException If the {@code String}
324 * does not contain a parsable {@code short}.
325 * @see java.lang.Short#parseShort(java.lang.String, int)
326 */
327 public Short(String s) throws NumberFormatException {
328 this.value = parseShort(s, 10);
329 }
330
331 /**
332 * Returns the value of this {@code Short} as a {@code byte} after
333 * a narrowing primitive conversion.
334 * @jls 5.1.3 Narrowing Primitive Conversions
335 */
336 public byte byteValue() {
337 return (byte)value;
338 }
339
340 /**
341 * Returns the value of this {@code Short} as a
342 * {@code short}.
343 */
344 @HotSpotIntrinsicCandidate
345 public short shortValue() {
346 return value;
347 }
348
349 /**
350 * Returns the value of this {@code Short} as an {@code int} after
351 * a widening primitive conversion.
352 * @jls 5.1.2 Widening Primitive Conversions
353 */
354 public int intValue() {
355 return (int)value;
356 }
357
358 /**
359 * Returns the value of this {@code Short} as a {@code long} after
360 * a widening primitive conversion.
361 * @jls 5.1.2 Widening Primitive Conversions
362 */
363 public long longValue() {
364 return (long)value;
365 }
366
367 /**
368 * Returns the value of this {@code Short} as a {@code float}
369 * after a widening primitive conversion.
370 * @jls 5.1.2 Widening Primitive Conversions
371 */
372 public float floatValue() {
373 return (float)value;
374 }
375
376 /**
377 * Returns the value of this {@code Short} as a {@code double}
378 * after a widening primitive conversion.
379 * @jls 5.1.2 Widening Primitive Conversions
380 */
381 public double doubleValue() {
382 return (double)value;
383 }
384
385 /**
386 * Returns a {@code String} object representing this
387 * {@code Short}'s value. The value is converted to signed
388 * decimal representation and returned as a string, exactly as if
389 * the {@code short} value were given as an argument to the
390 * {@link java.lang.Short#toString(short)} method.
391 *
392 * @return a string representation of the value of this object in
393 * base 10.
394 */
395 public String toString() {
396 return Integer.toString((int)value);
397 }
398
399 /**
400 * Returns a hash code for this {@code Short}; equal to the result
401 * of invoking {@code intValue()}.
402 *
403 * @return a hash code value for this {@code Short}
404 */
405 @Override
406 public int hashCode() {
407 return Short.hashCode(value);
408 }
409
410 /**
411 * Returns a hash code for a {@code short} value; compatible with
412 * {@code Short.hashCode()}.
413 *
414 * @param value the value to hash
415 * @return a hash code value for a {@code short} value.
416 * @since 1.8
417 */
418 public static int hashCode(short value) {
419 return (int)value;
420 }
421
422 /**
423 * Compares this object to the specified object. The result is
424 * {@code true} if and only if the argument is not
425 * {@code null} and is a {@code Short} object that
426 * contains the same {@code short} value as this object.
427 *
428 * @param obj the object to compare with
429 * @return {@code true} if the objects are the same;
430 * {@code false} otherwise.
431 */
432 public boolean equals(Object obj) {
433 if (obj instanceof Short) {
434 return value == ((Short)obj).shortValue();
435 }
436 return false;
437 }
438
439 /**
440 * Compares two {@code Short} objects numerically.
441 *
442 * @param anotherShort the {@code Short} to be compared.
443 * @return the value {@code 0} if this {@code Short} is
444 * equal to the argument {@code Short}; a value less than
445 * {@code 0} if this {@code Short} is numerically less
446 * than the argument {@code Short}; and a value greater than
447 * {@code 0} if this {@code Short} is numerically
448 * greater than the argument {@code Short} (signed
449 * comparison).
450 * @since 1.2
451 */
452 public int compareTo(Short anotherShort) {
453 return compare(this.value, anotherShort.value);
454 }
455
456 /**
457 * Compares two {@code short} values numerically.
458 * The value returned is identical to what would be returned by:
459 * <pre>
460 * Short.valueOf(x).compareTo(Short.valueOf(y))
461 * </pre>
462 *
463 * @param x the first {@code short} to compare
464 * @param y the second {@code short} to compare
465 * @return the value {@code 0} if {@code x == y};
466 * a value less than {@code 0} if {@code x < y}; and
467 * a value greater than {@code 0} if {@code x > y}
468 * @since 1.7
469 */
470 public static int compare(short x, short y) {
471 return x - y;
472 }
473
474 /**
475 * Compares two {@code short} values numerically treating the values
476 * as unsigned.
477 *
478 * @param x the first {@code short} to compare
479 * @param y the second {@code short} to compare
480 * @return the value {@code 0} if {@code x == y}; a value less
481 * than {@code 0} if {@code x < y} as unsigned values; and
482 * a value greater than {@code 0} if {@code x > y} as
483 * unsigned values
484 * @since 9
485 */
486 public static int compareUnsigned(short x, short y) {
487 return Short.toUnsignedInt(x) - Short.toUnsignedInt(y);
488 }
489
490 /**
491 * The number of bits used to represent a {@code short} value in two's
492 * complement binary form.
493 * @since 1.5
494 */
495 public static final int SIZE = 16;
496
497 /**
498 * The number of bytes used to represent a {@code short} value in two's
499 * complement binary form.
500 *
501 * @since 1.8
502 */
503 public static final int BYTES = SIZE / Byte.SIZE;
504
505 /**
506 * Returns the value obtained by reversing the order of the bytes in the
507 * two's complement representation of the specified {@code short} value.
508 *
509 * @param i the value whose bytes are to be reversed
510 * @return the value obtained by reversing (or, equivalently, swapping)
511 * the bytes in the specified {@code short} value.
512 * @since 1.5
513 */
514 @HotSpotIntrinsicCandidate
515 public static short reverseBytes(short i) {
516 return (short) (((i & 0xFF00) >> 8) | (i << 8));
517 }
518
519
520 /**
521 * Converts the argument to an {@code int} by an unsigned
522 * conversion. In an unsigned conversion to an {@code int}, the
523 * high-order 16 bits of the {@code int} are zero and the
524 * low-order 16 bits are equal to the bits of the {@code short} argument.
525 *
526 * Consequently, zero and positive {@code short} values are mapped
527 * to a numerically equal {@code int} value and negative {@code
528 * short} values are mapped to an {@code int} value equal to the
529 * input plus 2<sup>16</sup>.
530 *
531 * @param x the value to convert to an unsigned {@code int}
532 * @return the argument converted to {@code int} by an unsigned
533 * conversion
534 * @since 1.8
535 */
536 public static int toUnsignedInt(short x) {
537 return ((int) x) & 0xffff;
538 }
539
540 /**
541 * Converts the argument to a {@code long} by an unsigned
542 * conversion. In an unsigned conversion to a {@code long}, the
543 * high-order 48 bits of the {@code long} are zero and the
544 * low-order 16 bits are equal to the bits of the {@code short} argument.
545 *
546 * Consequently, zero and positive {@code short} values are mapped
547 * to a numerically equal {@code long} value and negative {@code
548 * short} values are mapped to a {@code long} value equal to the
549 * input plus 2<sup>16</sup>.
550 *
551 * @param x the value to convert to an unsigned {@code long}
552 * @return the argument converted to {@code long} by an unsigned
553 * conversion
554 * @since 1.8
555 */
556 public static long toUnsignedLong(short x) {
557 return ((long) x) & 0xffffL;
558 }
559
560 /** use serialVersionUID from JDK 1.1. for interoperability */
561 private static final long serialVersionUID = 7515723908773894738L;
562 }