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 /**
67 * Returns a new {@code String} object representing the
68 * specified {@code short}. The radix is assumed to be 10.
69 *
70 * @param s the {@code short} to be converted
71 * @return the string representation of the specified {@code short}
72 * @see java.lang.Integer#toString(int)
73 */
74 public static String toString(short s) {
75 return Integer.toString((int)s, 10);
76 }
77
78 /**
79 * Parses the string argument as a signed {@code short} in the
80 * radix specified by the second argument. The characters in the
81 * string must all be digits, of the specified radix (as
82 * determined by whether {@link java.lang.Character#digit(char,
83 * int)} returns a nonnegative value) except that the first
84 * character may be an ASCII minus sign {@code '-'}
85 * ({@code '\u005Cu002D'}) to indicate a negative value or an
86 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
87 * indicate a positive value. The resulting {@code short} value
88 * is returned.
89 *
90 * <p>An exception of type {@code NumberFormatException} is
91 * thrown if any of the following situations occurs:
92 * <ul>
93 * <li> The first argument is {@code null} or is a string of
94 * length zero.
95 *
96 * <li> The radix is either smaller than {@link
97 * java.lang.Character#MIN_RADIX} or larger than {@link
98 * java.lang.Character#MAX_RADIX}.
99 *
100 * <li> Any character of the string is not a digit of the
101 * specified radix, except that the first character may be a minus
102 * sign {@code '-'} ({@code '\u005Cu002D'}) or plus sign
103 * {@code '+'} ({@code '\u005Cu002B'}) provided that the
104 * string is longer than length 1.
105 *
106 * <li> The value represented by the string is not a value of type
107 * {@code short}.
108 * </ul>
109 *
110 * @param s the {@code String} containing the
111 * {@code short} representation to be parsed
112 * @param radix the radix to be used while parsing {@code s}
113 * @return the {@code short} represented by the string
114 * argument in the specified radix.
115 * @throws NumberFormatException If the {@code String}
116 * does not contain a parsable {@code short}.
117 */
118 public static short parseShort(String s, int radix)
119 throws NumberFormatException {
120 int i = Integer.parseInt(s, radix);
121 if (i < MIN_VALUE || i > MAX_VALUE)
122 throw new NumberFormatException(
123 "Value out of range. Value:\"" + s + "\" Radix:" + radix);
124 return (short)i;
125 }
126
127 /**
128 * Parses the string argument as a signed decimal {@code
129 * short}. The characters in the string must all be decimal
130 * digits, except that the first character may be an ASCII minus
131 * sign {@code '-'} ({@code '\u005Cu002D'}) to indicate a
132 * negative value or an ASCII plus sign {@code '+'}
133 * ({@code '\u005Cu002B'}) to indicate a positive value. The
134 * resulting {@code short} value is returned, exactly as if the
135 * argument and the radix 10 were given as arguments to the {@link
136 * #parseShort(java.lang.String, int)} method.
137 *
138 * @param s a {@code String} containing the {@code short}
139 * representation to be parsed
140 * @return the {@code short} value represented by the
141 * argument in decimal.
142 * @throws NumberFormatException If the string does not
143 * contain a parsable {@code short}.
144 */
145 public static short parseShort(String s) throws NumberFormatException {
146 return parseShort(s, 10);
147 }
148
149 /**
150 * Returns a {@code Short} object holding the value
151 * extracted from the specified {@code String} when parsed
152 * with the radix given by the second argument. The first argument
153 * is interpreted as representing a signed {@code short} in
154 * the radix specified by the second argument, exactly as if the
155 * argument were given to the {@link #parseShort(java.lang.String,
156 * int)} method. The result is a {@code Short} object that
157 * represents the {@code short} value specified by the string.
158 *
159 * <p>In other words, this method returns a {@code Short} object
160 * equal to the value of:
161 *
162 * <blockquote>
163 * {@code new Short(Short.parseShort(s, radix))}
164 * </blockquote>
165 *
166 * @param s the string to be parsed
167 * @param radix the radix to be used in interpreting {@code s}
168 * @return a {@code Short} object holding the value
169 * represented by the string argument in the
170 * specified radix.
171 * @throws NumberFormatException If the {@code String} does
172 * not contain a parsable {@code short}.
173 */
174 public static Short valueOf(String s, int radix)
175 throws NumberFormatException {
176 return valueOf(parseShort(s, radix));
177 }
178
179 /**
180 * Returns a {@code Short} object holding the
181 * value given by the specified {@code String}. The argument
182 * is interpreted as representing a signed decimal
183 * {@code short}, exactly as if the argument were given to
184 * the {@link #parseShort(java.lang.String)} method. The result is
185 * a {@code Short} object that represents the
186 * {@code short} value specified by the string.
187 *
188 * <p>In other words, this method returns a {@code Short} object
189 * equal to the value of:
190 *
191 * <blockquote>
192 * {@code new Short(Short.parseShort(s))}
193 * </blockquote>
194 *
195 * @param s the string to be parsed
196 * @return a {@code Short} object holding the value
197 * represented by the string argument
198 * @throws NumberFormatException If the {@code String} does
199 * not contain a parsable {@code short}.
200 */
201 public static Short valueOf(String s) throws NumberFormatException {
202 return valueOf(s, 10);
203 }
204
205 private static class ShortCache {
206 private ShortCache(){}
207
208 static final Short cache[] = new Short[-(-128) + 127 + 1];
209
210 static {
211 for(int i = 0; i < cache.length; i++)
212 cache[i] = new Short((short)(i - 128));
213 }
214 }
215
216 /**
217 * Returns a {@code Short} instance representing the specified
218 * {@code short} value.
219 * If a new {@code Short} instance is not required, this method
220 * should generally be used in preference to the constructor
221 * {@link #Short(short)}, as this method is likely to yield
222 * significantly better space and time performance by caching
223 * frequently requested values.
224 *
225 * This method will always cache values in the range -128 to 127,
226 * inclusive, and may cache other values outside of this range.
227 *
228 * @param s a short value.
229 * @return a {@code Short} instance representing {@code s}.
230 * @since 1.5
231 */
232 @HotSpotIntrinsicCandidate
233 public static Short valueOf(short s) {
234 final int offset = 128;
235 int sAsInt = s;
236 if (sAsInt >= -128 && sAsInt <= 127) { // must cache
237 return ShortCache.cache[sAsInt + offset];
238 }
239 return new Short(s);
240 }
241
242 /**
243 * Decodes a {@code String} into a {@code Short}.
244 * Accepts decimal, hexadecimal, and octal numbers given by
245 * the following grammar:
246 *
247 * <blockquote>
248 * <dl>
249 * <dt><i>DecodableString:</i>
250 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
251 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
252 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
253 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
254 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
255 *
256 * <dt><i>Sign:</i>
257 * <dd>{@code -}
258 * <dd>{@code +}
259 * </dl>
260 * </blockquote>
261 *
262 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
263 * are as defined in section 3.10.1 of
264 * <cite>The Java™ Language Specification</cite>,
265 * except that underscores are not accepted between digits.
266 *
267 * <p>The sequence of characters following an optional
268 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
269 * "{@code #}", or leading zero) is parsed as by the {@code
270 * Short.parseShort} method with the indicated radix (10, 16, or
271 * 8). This sequence of characters must represent a positive
272 * value or a {@link NumberFormatException} will be thrown. The
273 * result is negated if first character of the specified {@code
274 * String} is the minus sign. No whitespace characters are
275 * permitted in the {@code String}.
276 *
277 * @param nm the {@code String} to decode.
278 * @return a {@code Short} object holding the {@code short}
279 * value represented by {@code nm}
280 * @throws NumberFormatException if the {@code String} does not
281 * contain a parsable {@code short}.
282 * @see java.lang.Short#parseShort(java.lang.String, int)
283 */
284 public static Short decode(String nm) throws NumberFormatException {
285 int i = Integer.decode(nm);
286 if (i < MIN_VALUE || i > MAX_VALUE)
287 throw new NumberFormatException(
288 "Value " + i + " out of range from input " + nm);
289 return valueOf((short)i);
290 }
291
292 /**
293 * The value of the {@code Short}.
294 *
295 * @serial
296 */
297 private final short value;
298
299 /**
300 * Constructs a newly allocated {@code Short} object that
301 * represents the specified {@code short} value.
302 *
303 * @param value the value to be represented by the
304 * {@code Short}.
305 */
306 public Short(short value) {
307 this.value = value;
308 }
309
310 /**
311 * Constructs a newly allocated {@code Short} object that
312 * represents the {@code short} value indicated by the
313 * {@code String} parameter. The string is converted to a
314 * {@code short} value in exactly the manner used by the
315 * {@code parseShort} method for radix 10.
316 *
317 * @param s the {@code String} to be converted to a
318 * {@code Short}
319 * @throws NumberFormatException If the {@code String}
320 * does not contain a parsable {@code short}.
321 * @see java.lang.Short#parseShort(java.lang.String, int)
322 */
323 public Short(String s) throws NumberFormatException {
324 this.value = parseShort(s, 10);
325 }
326
327 /**
328 * Returns the value of this {@code Short} as a {@code byte} after
329 * a narrowing primitive conversion.
330 * @jls 5.1.3 Narrowing Primitive Conversions
331 */
332 public byte byteValue() {
333 return (byte)value;
334 }
335
336 /**
337 * Returns the value of this {@code Short} as a
338 * {@code short}.
339 */
340 @HotSpotIntrinsicCandidate
341 public short shortValue() {
342 return value;
343 }
344
345 /**
346 * Returns the value of this {@code Short} as an {@code int} after
347 * a widening primitive conversion.
348 * @jls 5.1.2 Widening Primitive Conversions
349 */
350 public int intValue() {
351 return (int)value;
352 }
353
354 /**
355 * Returns the value of this {@code Short} as a {@code long} after
356 * a widening primitive conversion.
357 * @jls 5.1.2 Widening Primitive Conversions
358 */
359 public long longValue() {
360 return (long)value;
361 }
362
363 /**
364 * Returns the value of this {@code Short} as a {@code float}
365 * after a widening primitive conversion.
366 * @jls 5.1.2 Widening Primitive Conversions
367 */
368 public float floatValue() {
369 return (float)value;
370 }
371
372 /**
373 * Returns the value of this {@code Short} as a {@code double}
374 * after a widening primitive conversion.
375 * @jls 5.1.2 Widening Primitive Conversions
376 */
377 public double doubleValue() {
378 return (double)value;
379 }
380
381 /**
382 * Returns a {@code String} object representing this
383 * {@code Short}'s value. The value is converted to signed
384 * decimal representation and returned as a string, exactly as if
385 * the {@code short} value were given as an argument to the
386 * {@link java.lang.Short#toString(short)} method.
387 *
388 * @return a string representation of the value of this object in
389 * base 10.
390 */
391 public String toString() {
392 return Integer.toString((int)value);
393 }
394
395 /**
396 * Returns a hash code for this {@code Short}; equal to the result
397 * of invoking {@code intValue()}.
398 *
399 * @return a hash code value for this {@code Short}
400 */
401 @Override
402 public int hashCode() {
403 return Short.hashCode(value);
404 }
405
406 /**
407 * Returns a hash code for a {@code short} value; compatible with
408 * {@code Short.hashCode()}.
409 *
410 * @param value the value to hash
411 * @return a hash code value for a {@code short} value.
412 * @since 1.8
413 */
414 public static int hashCode(short value) {
415 return (int)value;
416 }
417
418 /**
419 * Compares this object to the specified object. The result is
420 * {@code true} if and only if the argument is not
421 * {@code null} and is a {@code Short} object that
422 * contains the same {@code short} value as this object.
423 *
424 * @param obj the object to compare with
425 * @return {@code true} if the objects are the same;
426 * {@code false} otherwise.
427 */
428 public boolean equals(Object obj) {
429 if (obj instanceof Short) {
430 return value == ((Short)obj).shortValue();
431 }
432 return false;
433 }
434
435 /**
436 * Compares two {@code Short} objects numerically.
437 *
438 * @param anotherShort the {@code Short} to be compared.
439 * @return the value {@code 0} if this {@code Short} is
440 * equal to the argument {@code Short}; a value less than
441 * {@code 0} if this {@code Short} is numerically less
442 * than the argument {@code Short}; and a value greater than
443 * {@code 0} if this {@code Short} is numerically
444 * greater than the argument {@code Short} (signed
445 * comparison).
446 * @since 1.2
447 */
448 public int compareTo(Short anotherShort) {
449 return compare(this.value, anotherShort.value);
450 }
451
452 /**
453 * Compares two {@code short} values numerically.
454 * The value returned is identical to what would be returned by:
455 * <pre>
456 * Short.valueOf(x).compareTo(Short.valueOf(y))
457 * </pre>
458 *
459 * @param x the first {@code short} to compare
460 * @param y the second {@code short} to compare
461 * @return the value {@code 0} if {@code x == y};
462 * a value less than {@code 0} if {@code x < y}; and
463 * a value greater than {@code 0} if {@code x > y}
464 * @since 1.7
465 */
466 public static int compare(short x, short y) {
467 return x - y;
468 }
469
470 /**
471 * The number of bits used to represent a {@code short} value in two's
472 * complement binary form.
473 * @since 1.5
474 */
475 public static final int SIZE = 16;
476
477 /**
478 * The number of bytes used to represent a {@code short} value in two's
479 * complement binary form.
480 *
481 * @since 1.8
482 */
483 public static final int BYTES = SIZE / Byte.SIZE;
484
485 /**
486 * Returns the value obtained by reversing the order of the bytes in the
487 * two's complement representation of the specified {@code short} value.
488 *
489 * @param i the value whose bytes are to be reversed
490 * @return the value obtained by reversing (or, equivalently, swapping)
491 * the bytes in the specified {@code short} value.
492 * @since 1.5
493 */
494 @HotSpotIntrinsicCandidate
495 public static short reverseBytes(short i) {
496 return (short) (((i & 0xFF00) >> 8) | (i << 8));
497 }
498
499
500 /**
501 * Converts the argument to an {@code int} by an unsigned
502 * conversion. In an unsigned conversion to an {@code int}, the
503 * high-order 16 bits of the {@code int} are zero and the
504 * low-order 16 bits are equal to the bits of the {@code short} argument.
505 *
506 * Consequently, zero and positive {@code short} values are mapped
507 * to a numerically equal {@code int} value and negative {@code
508 * short} values are mapped to an {@code int} value equal to the
509 * input plus 2<sup>16</sup>.
510 *
511 * @param x the value to convert to an unsigned {@code int}
512 * @return the argument converted to {@code int} by an unsigned
513 * conversion
514 * @since 1.8
515 */
516 public static int toUnsignedInt(short x) {
517 return ((int) x) & 0xffff;
518 }
519
520 /**
521 * Converts the argument to a {@code long} by an unsigned
522 * conversion. In an unsigned conversion to a {@code long}, the
523 * high-order 48 bits of the {@code long} 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 long} value and negative {@code
528 * short} values are mapped to a {@code long} value equal to the
529 * input plus 2<sup>16</sup>.
530 *
531 * @param x the value to convert to an unsigned {@code long}
532 * @return the argument converted to {@code long} by an unsigned
533 * conversion
534 * @since 1.8
535 */
536 public static long toUnsignedLong(short x) {
537 return ((long) x) & 0xffffL;
538 }
539
540 /** use serialVersionUID from JDK 1.1. for interoperability */
541 private static final long serialVersionUID = 7515723908773894738L;
542 }