Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 1 | /* |
Yi Kong | cf86f33 | 2016-04-01 19:45:55 +0100 | [diff] [blame] | 2 | * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved. |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 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 | /** |
| 29 | * |
| 30 | * The {@code Byte} class wraps a value of primitive type {@code byte} |
| 31 | * in an object. An object of type {@code Byte} contains a single |
| 32 | * field whose type is {@code byte}. |
| 33 | * |
| 34 | * <p>In addition, this class provides several methods for converting |
| 35 | * a {@code byte} to a {@code String} and a {@code String} to a {@code |
| 36 | * byte}, as well as other constants and methods useful when dealing |
| 37 | * with a {@code byte}. |
| 38 | * |
| 39 | * @author Nakul Saraiya |
| 40 | * @author Joseph D. Darcy |
| 41 | * @see java.lang.Number |
| 42 | * @since JDK1.1 |
| 43 | */ |
| 44 | public final class Byte extends Number implements Comparable<Byte> { |
| 45 | |
| 46 | /** |
| 47 | * A constant holding the minimum value a {@code byte} can |
| 48 | * have, -2<sup>7</sup>. |
| 49 | */ |
| 50 | public static final byte MIN_VALUE = -128; |
| 51 | |
| 52 | /** |
| 53 | * A constant holding the maximum value a {@code byte} can |
| 54 | * have, 2<sup>7</sup>-1. |
| 55 | */ |
| 56 | public static final byte MAX_VALUE = 127; |
| 57 | |
| 58 | /** |
| 59 | * The {@code Class} instance representing the primitive type |
| 60 | * {@code byte}. |
| 61 | */ |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 62 | @SuppressWarnings("unchecked") |
Vladimir Marko | a636fa9 | 2018-02-15 10:41:59 +0000 | [diff] [blame] | 63 | public static final Class<Byte> TYPE = (Class<Byte>) Class.getPrimitiveClass("byte"); |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 64 | |
| 65 | /** |
| 66 | * Returns a new {@code String} object representing the |
| 67 | * specified {@code byte}. The radix is assumed to be 10. |
| 68 | * |
| 69 | * @param b the {@code byte} to be converted |
| 70 | * @return the string representation of the specified {@code byte} |
| 71 | * @see java.lang.Integer#toString(int) |
| 72 | */ |
| 73 | public static String toString(byte b) { |
| 74 | return Integer.toString((int)b, 10); |
| 75 | } |
| 76 | |
| 77 | private static class ByteCache { |
| 78 | private ByteCache(){} |
| 79 | |
| 80 | static final Byte cache[] = new Byte[-(-128) + 127 + 1]; |
| 81 | |
| 82 | static { |
| 83 | for(int i = 0; i < cache.length; i++) |
| 84 | cache[i] = new Byte((byte)(i - 128)); |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | /** |
| 89 | * Returns a {@code Byte} instance representing the specified |
| 90 | * {@code byte} value. |
| 91 | * If a new {@code Byte} instance is not required, this method |
| 92 | * should generally be used in preference to the constructor |
| 93 | * {@link #Byte(byte)}, as this method is likely to yield |
| 94 | * significantly better space and time performance since |
| 95 | * all byte values are cached. |
| 96 | * |
| 97 | * @param b a byte value. |
| 98 | * @return a {@code Byte} instance representing {@code b}. |
| 99 | * @since 1.5 |
| 100 | */ |
| 101 | public static Byte valueOf(byte b) { |
| 102 | final int offset = 128; |
| 103 | return ByteCache.cache[(int)b + offset]; |
| 104 | } |
| 105 | |
| 106 | /** |
| 107 | * Parses the string argument as a signed {@code byte} in the |
| 108 | * radix specified by the second argument. The characters in the |
| 109 | * string must all be digits, of the specified radix (as |
| 110 | * determined by whether {@link java.lang.Character#digit(char, |
| 111 | * int)} returns a nonnegative value) except that the first |
| 112 | * character may be an ASCII minus sign {@code '-'} |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 113 | * ({@code '\u005Cu002D'}) to indicate a negative value or an |
| 114 | * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 115 | * indicate a positive value. The resulting {@code byte} value is |
| 116 | * returned. |
| 117 | * |
| 118 | * <p>An exception of type {@code NumberFormatException} is |
| 119 | * thrown if any of the following situations occurs: |
| 120 | * <ul> |
| 121 | * <li> The first argument is {@code null} or is a string of |
| 122 | * length zero. |
| 123 | * |
| 124 | * <li> The radix is either smaller than {@link |
| 125 | * java.lang.Character#MIN_RADIX} or larger than {@link |
| 126 | * java.lang.Character#MAX_RADIX}. |
| 127 | * |
| 128 | * <li> Any character of the string is not a digit of the |
| 129 | * specified radix, except that the first character may be a minus |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 130 | * sign {@code '-'} ({@code '\u005Cu002D'}) or plus sign |
| 131 | * {@code '+'} ({@code '\u005Cu002B'}) provided that the |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 132 | * string is longer than length 1. |
| 133 | * |
| 134 | * <li> The value represented by the string is not a value of type |
| 135 | * {@code byte}. |
| 136 | * </ul> |
| 137 | * |
| 138 | * @param s the {@code String} containing the |
| 139 | * {@code byte} |
| 140 | * representation to be parsed |
| 141 | * @param radix the radix to be used while parsing {@code s} |
| 142 | * @return the {@code byte} value represented by the string |
| 143 | * argument in the specified radix |
| 144 | * @throws NumberFormatException If the string does |
| 145 | * not contain a parsable {@code byte}. |
| 146 | */ |
| 147 | public static byte parseByte(String s, int radix) |
| 148 | throws NumberFormatException { |
| 149 | int i = Integer.parseInt(s, radix); |
| 150 | if (i < MIN_VALUE || i > MAX_VALUE) |
| 151 | throw new NumberFormatException( |
| 152 | "Value out of range. Value:\"" + s + "\" Radix:" + radix); |
| 153 | return (byte)i; |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Parses the string argument as a signed decimal {@code |
| 158 | * byte}. The characters in the string must all be decimal digits, |
| 159 | * except that the first character may be an ASCII minus sign |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 160 | * {@code '-'} ({@code '\u005Cu002D'}) to indicate a negative |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 161 | * value or an ASCII plus sign {@code '+'} |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 162 | * ({@code '\u005Cu002B'}) to indicate a positive value. The |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 163 | * resulting {@code byte} value is returned, exactly as if the |
| 164 | * argument and the radix 10 were given as arguments to the {@link |
| 165 | * #parseByte(java.lang.String, int)} method. |
| 166 | * |
| 167 | * @param s a {@code String} containing the |
| 168 | * {@code byte} representation to be parsed |
| 169 | * @return the {@code byte} value represented by the |
| 170 | * argument in decimal |
| 171 | * @throws NumberFormatException if the string does not |
| 172 | * contain a parsable {@code byte}. |
| 173 | */ |
| 174 | public static byte parseByte(String s) throws NumberFormatException { |
| 175 | return parseByte(s, 10); |
| 176 | } |
| 177 | |
| 178 | /** |
| 179 | * Returns a {@code Byte} object holding the value |
| 180 | * extracted from the specified {@code String} when parsed |
| 181 | * with the radix given by the second argument. The first argument |
| 182 | * is interpreted as representing a signed {@code byte} in |
| 183 | * the radix specified by the second argument, exactly as if the |
| 184 | * argument were given to the {@link #parseByte(java.lang.String, |
| 185 | * int)} method. The result is a {@code Byte} object that |
| 186 | * represents the {@code byte} value specified by the string. |
| 187 | * |
| 188 | * <p> In other words, this method returns a {@code Byte} object |
| 189 | * equal to the value of: |
| 190 | * |
| 191 | * <blockquote> |
| 192 | * {@code new Byte(Byte.parseByte(s, radix))} |
| 193 | * </blockquote> |
| 194 | * |
| 195 | * @param s the string to be parsed |
| 196 | * @param radix the radix to be used in interpreting {@code s} |
| 197 | * @return a {@code Byte} object holding the value |
| 198 | * represented by the string argument in the |
| 199 | * specified radix. |
| 200 | * @throws NumberFormatException If the {@code String} does |
| 201 | * not contain a parsable {@code byte}. |
| 202 | */ |
| 203 | public static Byte valueOf(String s, int radix) |
| 204 | throws NumberFormatException { |
| 205 | return valueOf(parseByte(s, radix)); |
| 206 | } |
| 207 | |
| 208 | /** |
| 209 | * Returns a {@code Byte} object holding the value |
| 210 | * given by the specified {@code String}. The argument is |
| 211 | * interpreted as representing a signed decimal {@code byte}, |
| 212 | * exactly as if the argument were given to the {@link |
| 213 | * #parseByte(java.lang.String)} method. The result is a |
| 214 | * {@code Byte} object that represents the {@code byte} |
| 215 | * value specified by the string. |
| 216 | * |
| 217 | * <p> In other words, this method returns a {@code Byte} object |
| 218 | * equal to the value of: |
| 219 | * |
| 220 | * <blockquote> |
| 221 | * {@code new Byte(Byte.parseByte(s))} |
| 222 | * </blockquote> |
| 223 | * |
| 224 | * @param s the string to be parsed |
| 225 | * @return a {@code Byte} object holding the value |
| 226 | * represented by the string argument |
| 227 | * @throws NumberFormatException If the {@code String} does |
| 228 | * not contain a parsable {@code byte}. |
| 229 | */ |
| 230 | public static Byte valueOf(String s) throws NumberFormatException { |
| 231 | return valueOf(s, 10); |
| 232 | } |
| 233 | |
| 234 | /** |
| 235 | * Decodes a {@code String} into a {@code Byte}. |
| 236 | * Accepts decimal, hexadecimal, and octal numbers given by |
| 237 | * the following grammar: |
| 238 | * |
| 239 | * <blockquote> |
| 240 | * <dl> |
| 241 | * <dt><i>DecodableString:</i> |
| 242 | * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i> |
| 243 | * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i> |
| 244 | * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i> |
| 245 | * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i> |
| 246 | * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i> |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 247 | * |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 248 | * <dt><i>Sign:</i> |
| 249 | * <dd>{@code -} |
| 250 | * <dd>{@code +} |
| 251 | * </dl> |
| 252 | * </blockquote> |
| 253 | * |
| 254 | * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i> |
| 255 | * are as defined in section 3.10.1 of |
| 256 | * <cite>The Java™ Language Specification</cite>, |
| 257 | * except that underscores are not accepted between digits. |
| 258 | * |
| 259 | * <p>The sequence of characters following an optional |
| 260 | * sign and/or radix specifier ("{@code 0x}", "{@code 0X}", |
| 261 | * "{@code #}", or leading zero) is parsed as by the {@code |
| 262 | * Byte.parseByte} method with the indicated radix (10, 16, or 8). |
| 263 | * This sequence of characters must represent a positive value or |
| 264 | * a {@link NumberFormatException} will be thrown. The result is |
| 265 | * negated if first character of the specified {@code String} is |
| 266 | * the minus sign. No whitespace characters are permitted in the |
| 267 | * {@code String}. |
| 268 | * |
| 269 | * @param nm the {@code String} to decode. |
| 270 | * @return a {@code Byte} object holding the {@code byte} |
| 271 | * value represented by {@code nm} |
| 272 | * @throws NumberFormatException if the {@code String} does not |
| 273 | * contain a parsable {@code byte}. |
| 274 | * @see java.lang.Byte#parseByte(java.lang.String, int) |
| 275 | */ |
| 276 | public static Byte decode(String nm) throws NumberFormatException { |
| 277 | int i = Integer.decode(nm); |
| 278 | if (i < MIN_VALUE || i > MAX_VALUE) |
| 279 | throw new NumberFormatException( |
| 280 | "Value " + i + " out of range from input " + nm); |
| 281 | return valueOf((byte)i); |
| 282 | } |
| 283 | |
| 284 | /** |
| 285 | * The value of the {@code Byte}. |
| 286 | * |
| 287 | * @serial |
| 288 | */ |
| 289 | private final byte value; |
| 290 | |
| 291 | /** |
| 292 | * Constructs a newly allocated {@code Byte} object that |
| 293 | * represents the specified {@code byte} value. |
| 294 | * |
| 295 | * @param value the value to be represented by the |
| 296 | * {@code Byte}. |
| 297 | */ |
| 298 | public Byte(byte value) { |
| 299 | this.value = value; |
| 300 | } |
| 301 | |
| 302 | /** |
| 303 | * Constructs a newly allocated {@code Byte} object that |
| 304 | * represents the {@code byte} value indicated by the |
| 305 | * {@code String} parameter. The string is converted to a |
| 306 | * {@code byte} value in exactly the manner used by the |
| 307 | * {@code parseByte} method for radix 10. |
| 308 | * |
| 309 | * @param s the {@code String} to be converted to a |
| 310 | * {@code Byte} |
| 311 | * @throws NumberFormatException If the {@code String} |
| 312 | * does not contain a parsable {@code byte}. |
| 313 | * @see java.lang.Byte#parseByte(java.lang.String, int) |
| 314 | */ |
| 315 | public Byte(String s) throws NumberFormatException { |
| 316 | this.value = parseByte(s, 10); |
| 317 | } |
| 318 | |
| 319 | /** |
| 320 | * Returns the value of this {@code Byte} as a |
| 321 | * {@code byte}. |
| 322 | */ |
| 323 | public byte byteValue() { |
| 324 | return value; |
| 325 | } |
| 326 | |
| 327 | /** |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 328 | * Returns the value of this {@code Byte} as a {@code short} after |
| 329 | * a widening primitive conversion. |
| 330 | * @jls 5.1.2 Widening Primitive Conversions |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 331 | */ |
| 332 | public short shortValue() { |
| 333 | return (short)value; |
| 334 | } |
| 335 | |
| 336 | /** |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 337 | * Returns the value of this {@code Byte} as an {@code int} after |
| 338 | * a widening primitive conversion. |
| 339 | * @jls 5.1.2 Widening Primitive Conversions |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 340 | */ |
| 341 | public int intValue() { |
| 342 | return (int)value; |
| 343 | } |
| 344 | |
| 345 | /** |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 346 | * Returns the value of this {@code Byte} as a {@code long} after |
| 347 | * a widening primitive conversion. |
| 348 | * @jls 5.1.2 Widening Primitive Conversions |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 349 | */ |
| 350 | public long longValue() { |
| 351 | return (long)value; |
| 352 | } |
| 353 | |
| 354 | /** |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 355 | * Returns the value of this {@code Byte} as a {@code float} after |
| 356 | * a widening primitive conversion. |
| 357 | * @jls 5.1.2 Widening Primitive Conversions |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 358 | */ |
| 359 | public float floatValue() { |
| 360 | return (float)value; |
| 361 | } |
| 362 | |
| 363 | /** |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 364 | * Returns the value of this {@code Byte} as a {@code double} |
| 365 | * after a widening primitive conversion. |
| 366 | * @jls 5.1.2 Widening Primitive Conversions |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 367 | */ |
| 368 | public double doubleValue() { |
| 369 | return (double)value; |
| 370 | } |
| 371 | |
| 372 | /** |
| 373 | * Returns a {@code String} object representing this |
| 374 | * {@code Byte}'s value. The value is converted to signed |
| 375 | * decimal representation and returned as a string, exactly as if |
| 376 | * the {@code byte} value were given as an argument to the |
| 377 | * {@link java.lang.Byte#toString(byte)} method. |
| 378 | * |
| 379 | * @return a string representation of the value of this object in |
| 380 | * base 10. |
| 381 | */ |
| 382 | public String toString() { |
| 383 | return Integer.toString((int)value); |
| 384 | } |
| 385 | |
| 386 | /** |
| 387 | * Returns a hash code for this {@code Byte}; equal to the result |
| 388 | * of invoking {@code intValue()}. |
| 389 | * |
| 390 | * @return a hash code value for this {@code Byte} |
| 391 | */ |
Przemyslaw Szczepaniak | 25fbd65 | 2016-06-16 11:33:38 +0100 | [diff] [blame] | 392 | @Override |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 393 | public int hashCode() { |
Yi Kong | cf86f33 | 2016-04-01 19:45:55 +0100 | [diff] [blame] | 394 | return Byte.hashCode(value); |
| 395 | } |
| 396 | |
| 397 | /** |
| 398 | * Returns a hash code for a {@code byte} value; compatible with |
| 399 | * {@code Byte.hashCode()}. |
| 400 | * |
| 401 | * @param value the value to hash |
| 402 | * @return a hash code value for a {@code byte} value. |
| 403 | * @since 1.8 |
| 404 | */ |
| 405 | public static int hashCode(byte value) { |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 406 | return (int)value; |
| 407 | } |
| 408 | |
| 409 | /** |
| 410 | * Compares this object to the specified object. The result is |
| 411 | * {@code true} if and only if the argument is not |
| 412 | * {@code null} and is a {@code Byte} object that |
| 413 | * contains the same {@code byte} value as this object. |
| 414 | * |
| 415 | * @param obj the object to compare with |
| 416 | * @return {@code true} if the objects are the same; |
| 417 | * {@code false} otherwise. |
| 418 | */ |
| 419 | public boolean equals(Object obj) { |
| 420 | if (obj instanceof Byte) { |
| 421 | return value == ((Byte)obj).byteValue(); |
| 422 | } |
| 423 | return false; |
| 424 | } |
| 425 | |
| 426 | /** |
| 427 | * Compares two {@code Byte} objects numerically. |
| 428 | * |
| 429 | * @param anotherByte the {@code Byte} to be compared. |
| 430 | * @return the value {@code 0} if this {@code Byte} is |
| 431 | * equal to the argument {@code Byte}; a value less than |
| 432 | * {@code 0} if this {@code Byte} is numerically less |
| 433 | * than the argument {@code Byte}; and a value greater than |
| 434 | * {@code 0} if this {@code Byte} is numerically |
| 435 | * greater than the argument {@code Byte} (signed |
| 436 | * comparison). |
| 437 | * @since 1.2 |
| 438 | */ |
| 439 | public int compareTo(Byte anotherByte) { |
| 440 | return compare(this.value, anotherByte.value); |
| 441 | } |
| 442 | |
| 443 | /** |
| 444 | * Compares two {@code byte} values numerically. |
| 445 | * The value returned is identical to what would be returned by: |
| 446 | * <pre> |
| 447 | * Byte.valueOf(x).compareTo(Byte.valueOf(y)) |
| 448 | * </pre> |
| 449 | * |
| 450 | * @param x the first {@code byte} to compare |
| 451 | * @param y the second {@code byte} to compare |
| 452 | * @return the value {@code 0} if {@code x == y}; |
| 453 | * a value less than {@code 0} if {@code x < y}; and |
| 454 | * a value greater than {@code 0} if {@code x > y} |
| 455 | * @since 1.7 |
| 456 | */ |
| 457 | public static int compare(byte x, byte y) { |
| 458 | return x - y; |
| 459 | } |
| 460 | |
| 461 | /** |
Yi Kong | e2f147b | 2016-05-04 17:24:00 +0100 | [diff] [blame] | 462 | * Converts the argument to an {@code int} by an unsigned |
| 463 | * conversion. In an unsigned conversion to an {@code int}, the |
| 464 | * high-order 24 bits of the {@code int} are zero and the |
| 465 | * low-order 8 bits are equal to the bits of the {@code byte} argument. |
| 466 | * |
| 467 | * Consequently, zero and positive {@code byte} values are mapped |
| 468 | * to a numerically equal {@code int} value and negative {@code |
| 469 | * byte} values are mapped to an {@code int} value equal to the |
| 470 | * input plus 2<sup>8</sup>. |
| 471 | * |
| 472 | * @param x the value to convert to an unsigned {@code int} |
| 473 | * @return the argument converted to {@code int} by an unsigned |
| 474 | * conversion |
| 475 | * @since 1.8 |
| 476 | */ |
| 477 | public static int toUnsignedInt(byte x) { |
| 478 | return ((int) x) & 0xff; |
| 479 | } |
| 480 | |
| 481 | /** |
| 482 | * Converts the argument to a {@code long} by an unsigned |
| 483 | * conversion. In an unsigned conversion to a {@code long}, the |
| 484 | * high-order 56 bits of the {@code long} are zero and the |
| 485 | * low-order 8 bits are equal to the bits of the {@code byte} argument. |
| 486 | * |
| 487 | * Consequently, zero and positive {@code byte} values are mapped |
| 488 | * to a numerically equal {@code long} value and negative {@code |
| 489 | * byte} values are mapped to a {@code long} value equal to the |
| 490 | * input plus 2<sup>8</sup>. |
| 491 | * |
| 492 | * @param x the value to convert to an unsigned {@code long} |
| 493 | * @return the argument converted to {@code long} by an unsigned |
| 494 | * conversion |
| 495 | * @since 1.8 |
| 496 | */ |
| 497 | public static long toUnsignedLong(byte x) { |
| 498 | return ((long) x) & 0xffL; |
| 499 | } |
| 500 | |
| 501 | |
| 502 | /** |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 503 | * The number of bits used to represent a {@code byte} value in two's |
| 504 | * complement binary form. |
| 505 | * |
| 506 | * @since 1.5 |
| 507 | */ |
| 508 | public static final int SIZE = 8; |
| 509 | |
Yi Kong | cf86f33 | 2016-04-01 19:45:55 +0100 | [diff] [blame] | 510 | /** |
| 511 | * The number of bytes used to represent a {@code byte} value in two's |
| 512 | * complement binary form. |
| 513 | * |
| 514 | * @since 1.8 |
| 515 | */ |
| 516 | public static final int BYTES = SIZE / Byte.SIZE; |
| 517 | |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 518 | /** use serialVersionUID from JDK 1.1. for interoperability */ |
| 519 | private static final long serialVersionUID = -7183698231559129828L; |
Piotr Jastrzebski | 46e3649 | 2015-05-06 14:48:00 +0100 | [diff] [blame] | 520 | |
Tobias Thierer | c315527 | 2017-04-13 19:12:46 +0100 | [diff] [blame] | 521 | // BEGIN Android-added: toHexString() for internal use. |
Tobias Thierer | 6975f84 | 2017-03-01 17:51:53 +0000 | [diff] [blame] | 522 | /** |
Piotr Jastrzebski | 46e3649 | 2015-05-06 14:48:00 +0100 | [diff] [blame] | 523 | * @hide |
| 524 | */ |
| 525 | public static String toHexString(byte b, boolean upperCase) { |
| 526 | char[] digits = upperCase ? UPPER_CASE_DIGITS : DIGITS; |
| 527 | char[] buf = new char[2]; // We always want two digits. |
| 528 | buf[0] = digits[(b >> 4) & 0xf]; |
| 529 | buf[1] = digits[b & 0xf]; |
| 530 | return new String(0, 2, buf); |
| 531 | } |
| 532 | private static final char[] DIGITS = { |
| 533 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 534 | 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', |
| 535 | 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', |
| 536 | 'u', 'v', 'w', 'x', 'y', 'z' |
| 537 | }; |
| 538 | |
| 539 | private static final char[] UPPER_CASE_DIGITS = { |
| 540 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
| 541 | 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', |
| 542 | 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', |
| 543 | 'U', 'V', 'W', 'X', 'Y', 'Z' |
| 544 | }; |
Tobias Thierer | c315527 | 2017-04-13 19:12:46 +0100 | [diff] [blame] | 545 | // END Android-added: toHexString() for internal use. |
Piotr Jastrzebski | 51b1b69 | 2015-02-16 15:01:09 +0000 | [diff] [blame] | 546 | } |