1 /* 2 * Copyright (c) 1996, 2024, 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.misc.CDS; 29 import jdk.internal.value.DeserializeConstructor; 30 import jdk.internal.vm.annotation.IntrinsicCandidate; 31 import jdk.internal.vm.annotation.Stable; 32 33 import java.lang.constant.Constable; 34 import java.lang.constant.DynamicConstantDesc; 35 import java.util.Optional; 36 37 import static java.lang.constant.ConstantDescs.BSM_EXPLICIT_CAST; 38 import static java.lang.constant.ConstantDescs.CD_short; 39 import static java.lang.constant.ConstantDescs.DEFAULT_NAME; 40 41 /** 42 * The {@code Short} class is the {@linkplain 43 * java.lang##wrapperClass wrapper class} for values of the primitive 44 * type {@code short}. An object of type {@code Short} contains a 45 * single field whose type is {@code short}. 46 * 47 * <p>In addition, this class provides several methods for converting 48 * a {@code short} to a {@code String} and a {@code String} to a 49 * {@code short}, as well as other constants and methods useful when 50 * dealing with a {@code short}. 51 * 52 * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a> 53 * class; programmers should treat instances that are 54 * {@linkplain #equals(Object) equal} as interchangeable and should not 55 * use instances for synchronization, or unpredictable behavior may 56 * occur. For example, in a future release, synchronization may fail. 57 * 58 * @author Nakul Saraiya 59 * @author Joseph D. Darcy 60 * @see java.lang.Number 61 * @since 1.1 62 */ 63 @jdk.internal.MigratedValueClass 64 @jdk.internal.ValueBased 65 public final class Short extends Number implements Comparable<Short>, Constable { 66 67 /** 68 * A constant holding the minimum value a {@code short} can 69 * have, -2<sup>15</sup>. 70 */ 71 public static final short MIN_VALUE = -32768; 72 73 /** 74 * A constant holding the maximum value a {@code short} can 75 * have, 2<sup>15</sup>-1. 76 */ 77 public static final short MAX_VALUE = 32767; 78 79 /** 80 * The {@code Class} instance representing the primitive type 81 * {@code short}. 82 */ 83 @SuppressWarnings("unchecked") 84 public static final Class<Short> TYPE = (Class<Short>) Class.getPrimitiveClass("short"); 85 86 /** 87 * Returns a new {@code String} object representing the 88 * specified {@code short}. The radix is assumed to be 10. 89 * 90 * @param s the {@code short} to be converted 91 * @return the string representation of the specified {@code short} 92 * @see java.lang.Integer#toString(int) 93 */ 94 public static String toString(short s) { 95 return Integer.toString(s); 96 } 97 98 /** 99 * Parses the string argument as a signed {@code short} in the 100 * radix specified by the second argument. The characters in the 101 * string must all be digits, of the specified radix (as 102 * determined by whether {@link java.lang.Character#digit(char, 103 * int)} returns a nonnegative value) except that the first 104 * character may be an ASCII minus sign {@code '-'} 105 * ({@code '\u005Cu002D'}) to indicate a negative value or an 106 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to 107 * indicate a positive value. The resulting {@code short} value 108 * is returned. 109 * 110 * <p>An exception of type {@code NumberFormatException} is 111 * thrown if any of the following situations occurs: 112 * <ul> 113 * <li> The first argument is {@code null} or is a string of 114 * length zero. 115 * 116 * <li> The radix is either smaller than {@link 117 * java.lang.Character#MIN_RADIX} or larger than {@link 118 * java.lang.Character#MAX_RADIX}. 119 * 120 * <li> Any character of the string is not a digit of the 121 * specified radix, except that the first character may be a minus 122 * sign {@code '-'} ({@code '\u005Cu002D'}) or plus sign 123 * {@code '+'} ({@code '\u005Cu002B'}) provided that the 124 * string is longer than length 1. 125 * 126 * <li> The value represented by the string is not a value of type 127 * {@code short}. 128 * </ul> 129 * 130 * @param s the {@code String} containing the 131 * {@code short} representation to be parsed 132 * @param radix the radix to be used while parsing {@code s} 133 * @return the {@code short} represented by the string 134 * argument in the specified radix. 135 * @throws NumberFormatException If the {@code String} 136 * does not contain a parsable {@code short}. 137 */ 138 public static short parseShort(String s, int radix) 139 throws NumberFormatException { 140 int i = Integer.parseInt(s, radix); 141 if (i < MIN_VALUE || i > MAX_VALUE) 142 throw new NumberFormatException( 143 "Value out of range. Value:\"" + s + "\" Radix:" + radix); 144 return (short)i; 145 } 146 147 /** 148 * Parses the string argument as a signed decimal {@code 149 * short}. The characters in the string must all be decimal 150 * digits, except that the first character may be an ASCII minus 151 * sign {@code '-'} ({@code '\u005Cu002D'}) to indicate a 152 * negative value or an ASCII plus sign {@code '+'} 153 * ({@code '\u005Cu002B'}) to indicate a positive value. The 154 * resulting {@code short} value is returned, exactly as if the 155 * argument and the radix 10 were given as arguments to the {@link 156 * #parseShort(java.lang.String, int)} method. 157 * 158 * @param s a {@code String} containing the {@code short} 159 * representation to be parsed 160 * @return the {@code short} value represented by the 161 * argument in decimal. 162 * @throws NumberFormatException If the string does not 163 * contain a parsable {@code short}. 164 */ 165 public static short parseShort(String s) throws NumberFormatException { 166 return parseShort(s, 10); 167 } 168 169 /** 170 * Returns a {@code Short} object holding the value 171 * extracted from the specified {@code String} when parsed 172 * with the radix given by the second argument. The first argument 173 * is interpreted as representing a signed {@code short} in 174 * the radix specified by the second argument, exactly as if the 175 * argument were given to the {@link #parseShort(java.lang.String, 176 * int)} method. The result is a {@code Short} object that 177 * represents the {@code short} value specified by the string. 178 * 179 * <p>In other words, this method returns a {@code Short} object 180 * equal to the value of: 181 * 182 * <blockquote> 183 * {@code Short.valueOf(Short.parseShort(s, radix))} 184 * </blockquote> 185 * 186 * @param s the string to be parsed 187 * @param radix the radix to be used in interpreting {@code s} 188 * @return a {@code Short} object holding the value 189 * represented by the string argument in the 190 * specified radix. 191 * @throws NumberFormatException If the {@code String} does 192 * not contain a parsable {@code short}. 193 */ 194 public static Short valueOf(String s, int radix) 195 throws NumberFormatException { 196 return valueOf(parseShort(s, radix)); 197 } 198 199 /** 200 * Returns a {@code Short} object holding the 201 * value given by the specified {@code String}. The argument 202 * is interpreted as representing a signed decimal 203 * {@code short}, exactly as if the argument were given to 204 * the {@link #parseShort(java.lang.String)} method. The result is 205 * a {@code Short} object that represents the 206 * {@code short} value specified by the string. 207 * 208 * <p>In other words, this method returns a {@code Short} object 209 * equal to the value of: 210 * 211 * <blockquote> 212 * {@code Short.valueOf(Short.parseShort(s))} 213 * </blockquote> 214 * 215 * @param s the string to be parsed 216 * @return a {@code Short} object holding the value 217 * represented by the string argument 218 * @throws NumberFormatException If the {@code String} does 219 * not contain a parsable {@code short}. 220 */ 221 public static Short valueOf(String s) throws NumberFormatException { 222 return valueOf(s, 10); 223 } 224 225 /** 226 * Returns an {@link Optional} containing the nominal descriptor for this 227 * instance. 228 * 229 * @return an {@link Optional} describing the {@linkplain Short} instance 230 * @since 15 231 */ 232 @Override 233 public Optional<DynamicConstantDesc<Short>> describeConstable() { 234 return Optional.of(DynamicConstantDesc.ofNamed(BSM_EXPLICIT_CAST, DEFAULT_NAME, CD_short, intValue())); 235 } 236 237 private static final class ShortCache { 238 private ShortCache() {} 239 240 @Stable 241 static final Short[] cache; 242 static Short[] archivedCache; 243 244 static { 245 int size = -(-128) + 127 + 1; 246 247 // Load and use the archived cache if it exists 248 CDS.initializeFromArchive(ShortCache.class); 249 if (archivedCache == null || archivedCache.length != size) { 250 Short[] c = new Short[size]; 251 short value = -128; 252 for(int i = 0; i < size; i++) { 253 c[i] = new Short(value++); 254 } 255 archivedCache = c; 256 } 257 cache = archivedCache; 258 } 259 } 260 261 /** 262 * Returns a {@code Short} instance representing the specified 263 * {@code short} value. 264 * If a new {@code Short} instance is not required, this method 265 * should generally be used in preference to the constructor 266 * {@link #Short(short)}, as this method is likely to yield 267 * significantly better space and time performance by caching 268 * frequently requested values. 269 * 270 * This method will always cache values in the range -128 to 127, 271 * inclusive, and may cache other values outside of this range. 272 * 273 * @param s a short value. 274 * @return a {@code Short} instance representing {@code s}. 275 * @since 1.5 276 */ 277 @IntrinsicCandidate 278 @DeserializeConstructor 279 public static Short valueOf(short s) { 280 final int offset = 128; 281 int sAsInt = s; 282 if (sAsInt >= -128 && sAsInt <= 127) { // must cache 283 return ShortCache.cache[sAsInt + offset]; 284 } 285 return new Short(s); 286 } 287 288 /** 289 * Decodes a {@code String} into a {@code Short}. 290 * Accepts decimal, hexadecimal, and octal numbers given by 291 * the following grammar: 292 * 293 * <blockquote> 294 * <dl> 295 * <dt><i>DecodableString:</i> 296 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i> 297 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i> 298 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i> 299 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i> 300 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i> 301 * 302 * <dt><i>Sign:</i> 303 * <dd>{@code -} 304 * <dd>{@code +} 305 * </dl> 306 * </blockquote> 307 * 308 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i> 309 * are as defined in section {@jls 3.10.1} of 310 * <cite>The Java Language Specification</cite>, 311 * except that underscores are not accepted between digits. 312 * 313 * <p>The sequence of characters following an optional 314 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}", 315 * "{@code #}", or leading zero) is parsed as by the {@code 316 * Short.parseShort} method with the indicated radix (10, 16, or 317 * 8). This sequence of characters must represent a positive 318 * value or a {@link NumberFormatException} will be thrown. The 319 * result is negated if first character of the specified {@code 320 * String} is the minus sign. No whitespace characters are 321 * permitted in the {@code String}. 322 * 323 * @param nm the {@code String} to decode. 324 * @return a {@code Short} object holding the {@code short} 325 * value represented by {@code nm} 326 * @throws NumberFormatException if the {@code String} does not 327 * contain a parsable {@code short}. 328 * @see java.lang.Short#parseShort(java.lang.String, int) 329 */ 330 public static Short decode(String nm) throws NumberFormatException { 331 int i = Integer.decode(nm); 332 if (i < MIN_VALUE || i > MAX_VALUE) 333 throw new NumberFormatException( 334 "Value " + i + " out of range from input " + nm); 335 return valueOf((short)i); 336 } 337 338 /** 339 * The value of the {@code Short}. 340 * 341 * @serial 342 */ 343 private final short value; 344 345 /** 346 * Constructs a newly allocated {@code Short} object that 347 * represents the specified {@code short} value. 348 * 349 * @param value the value to be represented by the 350 * {@code Short}. 351 * 352 * @deprecated 353 * It is rarely appropriate to use this constructor. The static factory 354 * {@link #valueOf(short)} is generally a better choice, as it is 355 * likely to yield significantly better space and time performance. 356 */ 357 @Deprecated(since="9", forRemoval = true) 358 public Short(short value) { 359 this.value = value; 360 } 361 362 /** 363 * Constructs a newly allocated {@code Short} object that 364 * represents the {@code short} value indicated by the 365 * {@code String} parameter. The string is converted to a 366 * {@code short} value in exactly the manner used by the 367 * {@code parseShort} method for radix 10. 368 * 369 * @param s the {@code String} to be converted to a 370 * {@code Short} 371 * @throws NumberFormatException If the {@code String} 372 * does not contain a parsable {@code short}. 373 * 374 * @deprecated 375 * It is rarely appropriate to use this constructor. 376 * Use {@link #parseShort(String)} to convert a string to a 377 * {@code short} primitive, or use {@link #valueOf(String)} 378 * to convert a string to a {@code Short} object. 379 */ 380 @Deprecated(since="9", forRemoval = true) 381 public Short(String s) throws NumberFormatException { 382 this.value = parseShort(s, 10); 383 } 384 385 /** 386 * Returns the value of this {@code Short} as a {@code byte} after 387 * a narrowing primitive conversion. 388 * @jls 5.1.3 Narrowing Primitive Conversion 389 */ 390 public byte byteValue() { 391 return (byte)value; 392 } 393 394 /** 395 * Returns the value of this {@code Short} as a 396 * {@code short}. 397 */ 398 @IntrinsicCandidate 399 public short shortValue() { 400 return value; 401 } 402 403 /** 404 * Returns the value of this {@code Short} as an {@code int} after 405 * a widening primitive conversion. 406 * @jls 5.1.2 Widening Primitive Conversion 407 */ 408 public int intValue() { 409 return (int)value; 410 } 411 412 /** 413 * Returns the value of this {@code Short} as a {@code long} after 414 * a widening primitive conversion. 415 * @jls 5.1.2 Widening Primitive Conversion 416 */ 417 public long longValue() { 418 return (long)value; 419 } 420 421 /** 422 * Returns the value of this {@code Short} as a {@code float} 423 * after a widening primitive conversion. 424 * @jls 5.1.2 Widening Primitive Conversion 425 */ 426 public float floatValue() { 427 return (float)value; 428 } 429 430 /** 431 * Returns the value of this {@code Short} as a {@code double} 432 * after a widening primitive conversion. 433 * @jls 5.1.2 Widening Primitive Conversion 434 */ 435 public double doubleValue() { 436 return (double)value; 437 } 438 439 /** 440 * Returns a {@code String} object representing this 441 * {@code Short}'s value. The value is converted to signed 442 * decimal representation and returned as a string, exactly as if 443 * the {@code short} value were given as an argument to the 444 * {@link java.lang.Short#toString(short)} method. 445 * 446 * @return a string representation of the value of this object in 447 * base 10. 448 */ 449 @Override 450 public String toString() { 451 return Integer.toString(value); 452 } 453 454 /** 455 * Returns a hash code for this {@code Short}; equal to the result 456 * of invoking {@code intValue()}. 457 * 458 * @return a hash code value for this {@code Short} 459 */ 460 @Override 461 public int hashCode() { 462 return Short.hashCode(value); 463 } 464 465 /** 466 * Returns a hash code for a {@code short} value; compatible with 467 * {@code Short.hashCode()}. 468 * 469 * @param value the value to hash 470 * @return a hash code value for a {@code short} value. 471 * @since 1.8 472 */ 473 public static int hashCode(short value) { 474 return (int)value; 475 } 476 477 /** 478 * Compares this object to the specified object. The result is 479 * {@code true} if and only if the argument is not 480 * {@code null} and is a {@code Short} object that 481 * contains the same {@code short} value as this object. 482 * 483 * @param obj the object to compare with 484 * @return {@code true} if the objects are the same; 485 * {@code false} otherwise. 486 */ 487 public boolean equals(Object obj) { 488 if (obj instanceof Short) { 489 return value == ((Short)obj).shortValue(); 490 } 491 return false; 492 } 493 494 /** 495 * Compares two {@code Short} objects numerically. 496 * 497 * @param anotherShort the {@code Short} to be compared. 498 * @return the value {@code 0} if this {@code Short} is 499 * equal to the argument {@code Short}; a value less than 500 * {@code 0} if this {@code Short} is numerically less 501 * than the argument {@code Short}; and a value greater than 502 * {@code 0} if this {@code Short} is numerically 503 * greater than the argument {@code Short} (signed 504 * comparison). 505 * @since 1.2 506 */ 507 public int compareTo(Short anotherShort) { 508 return compare(this.value, anotherShort.value); 509 } 510 511 /** 512 * Compares two {@code short} values numerically. 513 * The value returned is identical to what would be returned by: 514 * <pre> 515 * Short.valueOf(x).compareTo(Short.valueOf(y)) 516 * </pre> 517 * 518 * @param x the first {@code short} to compare 519 * @param y the second {@code short} to compare 520 * @return the value {@code 0} if {@code x == y}; 521 * a value less than {@code 0} if {@code x < y}; and 522 * a value greater than {@code 0} if {@code x > y} 523 * @since 1.7 524 */ 525 public static int compare(short x, short y) { 526 return x - y; 527 } 528 529 /** 530 * Compares two {@code short} values numerically treating the values 531 * as unsigned. 532 * 533 * @param x the first {@code short} to compare 534 * @param y the second {@code short} to compare 535 * @return the value {@code 0} if {@code x == y}; a value less 536 * than {@code 0} if {@code x < y} as unsigned values; and 537 * a value greater than {@code 0} if {@code x > y} as 538 * unsigned values 539 * @since 9 540 */ 541 public static int compareUnsigned(short x, short y) { 542 return Short.toUnsignedInt(x) - Short.toUnsignedInt(y); 543 } 544 545 /** 546 * The number of bits used to represent a {@code short} value in two's 547 * complement binary form. 548 * @since 1.5 549 */ 550 public static final int SIZE = 16; 551 552 /** 553 * The number of bytes used to represent a {@code short} value in two's 554 * complement binary form. 555 * 556 * @since 1.8 557 */ 558 public static final int BYTES = SIZE / Byte.SIZE; 559 560 /** 561 * Returns the value obtained by reversing the order of the bytes in the 562 * two's complement representation of the specified {@code short} value. 563 * 564 * @param i the value whose bytes are to be reversed 565 * @return the value obtained by reversing (or, equivalently, swapping) 566 * the bytes in the specified {@code short} value. 567 * @since 1.5 568 */ 569 @IntrinsicCandidate 570 public static short reverseBytes(short i) { 571 return (short) (((i & 0xFF00) >> 8) | (i << 8)); 572 } 573 574 575 /** 576 * Converts the argument to an {@code int} by an unsigned 577 * conversion. In an unsigned conversion to an {@code int}, the 578 * high-order 16 bits of the {@code int} are zero and the 579 * low-order 16 bits are equal to the bits of the {@code short} argument. 580 * 581 * Consequently, zero and positive {@code short} values are mapped 582 * to a numerically equal {@code int} value and negative {@code 583 * short} values are mapped to an {@code int} value equal to the 584 * input plus 2<sup>16</sup>. 585 * 586 * @param x the value to convert to an unsigned {@code int} 587 * @return the argument converted to {@code int} by an unsigned 588 * conversion 589 * @since 1.8 590 */ 591 public static int toUnsignedInt(short x) { 592 return ((int) x) & 0xffff; 593 } 594 595 /** 596 * Converts the argument to a {@code long} by an unsigned 597 * conversion. In an unsigned conversion to a {@code long}, the 598 * high-order 48 bits of the {@code long} are zero and the 599 * low-order 16 bits are equal to the bits of the {@code short} argument. 600 * 601 * Consequently, zero and positive {@code short} values are mapped 602 * to a numerically equal {@code long} value and negative {@code 603 * short} values are mapped to a {@code long} value equal to the 604 * input plus 2<sup>16</sup>. 605 * 606 * @param x the value to convert to an unsigned {@code long} 607 * @return the argument converted to {@code long} by an unsigned 608 * conversion 609 * @since 1.8 610 */ 611 public static long toUnsignedLong(short x) { 612 return ((long) x) & 0xffffL; 613 } 614 615 /** use serialVersionUID from JDK 1.1. for interoperability */ 616 @java.io.Serial 617 private static final long serialVersionUID = 7515723908773894738L; 618 } --- EOF ---