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 26package java.lang; 27 28import 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 */ 45public 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 * @deprecated 307 * It is rarely appropriate to use this constructor. The static factory 308 * {@link #valueOf(short)} is generally a better choice, as it is 309 * likely to yield significantly better space and time performance. 310 */ 311 @Deprecated(since="9") 312 public Short(short value) { 313 this.value = value; 314 } 315 316 /** 317 * Constructs a newly allocated {@code Short} object that 318 * represents the {@code short} value indicated by the 319 * {@code String} parameter. The string is converted to a 320 * {@code short} value in exactly the manner used by the 321 * {@code parseShort} method for radix 10. 322 * 323 * @param s the {@code String} to be converted to a 324 * {@code Short} 325 * @throws NumberFormatException If the {@code String} 326 * does not contain a parsable {@code short}. 327 * 328 * @deprecated 329 * It is rarely appropriate to use this constructor. 330 * Use {@link #parseShort(String)} to convert a string to a 331 * {@code short} primitive, or use {@link #valueOf(String)} 332 * to convert a string to a {@code Short} object. 333 */ 334 @Deprecated(since="9") 335 public Short(String s) throws NumberFormatException { 336 this.value = parseShort(s, 10); 337 } 338 339 /** 340 * Returns the value of this {@code Short} as a {@code byte} after 341 * a narrowing primitive conversion. 342 * @jls 5.1.3 Narrowing Primitive Conversions 343 */ 344 public byte byteValue() { 345 return (byte)value; 346 } 347 348 /** 349 * Returns the value of this {@code Short} as a 350 * {@code short}. 351 */ 352 @HotSpotIntrinsicCandidate 353 public short shortValue() { 354 return value; 355 } 356 357 /** 358 * Returns the value of this {@code Short} as an {@code int} after 359 * a widening primitive conversion. 360 * @jls 5.1.2 Widening Primitive Conversions 361 */ 362 public int intValue() { 363 return (int)value; 364 } 365 366 /** 367 * Returns the value of this {@code Short} as a {@code long} after 368 * a widening primitive conversion. 369 * @jls 5.1.2 Widening Primitive Conversions 370 */ 371 public long longValue() { 372 return (long)value; 373 } 374 375 /** 376 * Returns the value of this {@code Short} as a {@code float} 377 * after a widening primitive conversion. 378 * @jls 5.1.2 Widening Primitive Conversions 379 */ 380 public float floatValue() { 381 return (float)value; 382 } 383 384 /** 385 * Returns the value of this {@code Short} as a {@code double} 386 * after a widening primitive conversion. 387 * @jls 5.1.2 Widening Primitive Conversions 388 */ 389 public double doubleValue() { 390 return (double)value; 391 } 392 393 /** 394 * Returns a {@code String} object representing this 395 * {@code Short}'s value. The value is converted to signed 396 * decimal representation and returned as a string, exactly as if 397 * the {@code short} value were given as an argument to the 398 * {@link java.lang.Short#toString(short)} method. 399 * 400 * @return a string representation of the value of this object in 401 * base 10. 402 */ 403 public String toString() { 404 return Integer.toString((int)value); 405 } 406 407 /** 408 * Returns a hash code for this {@code Short}; equal to the result 409 * of invoking {@code intValue()}. 410 * 411 * @return a hash code value for this {@code Short} 412 */ 413 @Override 414 public int hashCode() { 415 return Short.hashCode(value); 416 } 417 418 /** 419 * Returns a hash code for a {@code short} value; compatible with 420 * {@code Short.hashCode()}. 421 * 422 * @param value the value to hash 423 * @return a hash code value for a {@code short} value. 424 * @since 1.8 425 */ 426 public static int hashCode(short value) { 427 return (int)value; 428 } 429 430 /** 431 * Compares this object to the specified object. The result is 432 * {@code true} if and only if the argument is not 433 * {@code null} and is a {@code Short} object that 434 * contains the same {@code short} value as this object. 435 * 436 * @param obj the object to compare with 437 * @return {@code true} if the objects are the same; 438 * {@code false} otherwise. 439 */ 440 public boolean equals(Object obj) { 441 if (obj instanceof Short) { 442 return value == ((Short)obj).shortValue(); 443 } 444 return false; 445 } 446 447 /** 448 * Compares two {@code Short} objects numerically. 449 * 450 * @param anotherShort the {@code Short} to be compared. 451 * @return the value {@code 0} if this {@code Short} is 452 * equal to the argument {@code Short}; a value less than 453 * {@code 0} if this {@code Short} is numerically less 454 * than the argument {@code Short}; and a value greater than 455 * {@code 0} if this {@code Short} is numerically 456 * greater than the argument {@code Short} (signed 457 * comparison). 458 * @since 1.2 459 */ 460 public int compareTo(Short anotherShort) { 461 return compare(this.value, anotherShort.value); 462 } 463 464 /** 465 * Compares two {@code short} values numerically. 466 * The value returned is identical to what would be returned by: 467 * <pre> 468 * Short.valueOf(x).compareTo(Short.valueOf(y)) 469 * </pre> 470 * 471 * @param x the first {@code short} to compare 472 * @param y the second {@code short} to compare 473 * @return the value {@code 0} if {@code x == y}; 474 * a value less than {@code 0} if {@code x < y}; and 475 * a value greater than {@code 0} if {@code x > y} 476 * @since 1.7 477 */ 478 public static int compare(short x, short y) { 479 return x - y; 480 } 481 482 /** 483 * Compares two {@code short} values numerically treating the values 484 * as unsigned. 485 * 486 * @param x the first {@code short} to compare 487 * @param y the second {@code short} to compare 488 * @return the value {@code 0} if {@code x == y}; a value less 489 * than {@code 0} if {@code x < y} as unsigned values; and 490 * a value greater than {@code 0} if {@code x > y} as 491 * unsigned values 492 * @since 9 493 */ 494 public static int compareUnsigned(short x, short y) { 495 return Short.toUnsignedInt(x) - Short.toUnsignedInt(y); 496 } 497 498 /** 499 * The number of bits used to represent a {@code short} value in two's 500 * complement binary form. 501 * @since 1.5 502 */ 503 public static final int SIZE = 16; 504 505 /** 506 * The number of bytes used to represent a {@code short} value in two's 507 * complement binary form. 508 * 509 * @since 1.8 510 */ 511 public static final int BYTES = SIZE / Byte.SIZE; 512 513 /** 514 * Returns the value obtained by reversing the order of the bytes in the 515 * two's complement representation of the specified {@code short} value. 516 * 517 * @param i the value whose bytes are to be reversed 518 * @return the value obtained by reversing (or, equivalently, swapping) 519 * the bytes in the specified {@code short} value. 520 * @since 1.5 521 */ 522 @HotSpotIntrinsicCandidate 523 public static short reverseBytes(short i) { 524 return (short) (((i & 0xFF00) >> 8) | (i << 8)); 525 } 526 527 528 /** 529 * Converts the argument to an {@code int} by an unsigned 530 * conversion. In an unsigned conversion to an {@code int}, the 531 * high-order 16 bits of the {@code int} are zero and the 532 * low-order 16 bits are equal to the bits of the {@code short} argument. 533 * 534 * Consequently, zero and positive {@code short} values are mapped 535 * to a numerically equal {@code int} value and negative {@code 536 * short} values are mapped to an {@code int} value equal to the 537 * input plus 2<sup>16</sup>. 538 * 539 * @param x the value to convert to an unsigned {@code int} 540 * @return the argument converted to {@code int} by an unsigned 541 * conversion 542 * @since 1.8 543 */ 544 public static int toUnsignedInt(short x) { 545 return ((int) x) & 0xffff; 546 } 547 548 /** 549 * Converts the argument to a {@code long} by an unsigned 550 * conversion. In an unsigned conversion to a {@code long}, the 551 * high-order 48 bits of the {@code long} are zero and the 552 * low-order 16 bits are equal to the bits of the {@code short} argument. 553 * 554 * Consequently, zero and positive {@code short} values are mapped 555 * to a numerically equal {@code long} value and negative {@code 556 * short} values are mapped to a {@code long} value equal to the 557 * input plus 2<sup>16</sup>. 558 * 559 * @param x the value to convert to an unsigned {@code long} 560 * @return the argument converted to {@code long} by an unsigned 561 * conversion 562 * @since 1.8 563 */ 564 public static long toUnsignedLong(short x) { 565 return ((long) x) & 0xffffL; 566 } 567 568 /** use serialVersionUID from JDK 1.1. for interoperability */ 569 private static final long serialVersionUID = 7515723908773894738L; 570} 571