GNU Classpath (0.18) | ||
Frames | No Frames |
1: /* Byte.java -- object wrapper for byte 2: Copyright (C) 1998, 2001, 2002, 2005 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: 39: package java.lang; 40: 41: /** 42: * Instances of class <code>Byte</code> represent primitive <code>byte</code> 43: * values. 44: * 45: * Additionally, this class provides various helper functions and variables 46: * useful to bytes. 47: * 48: * @author Paul Fisher 49: * @author John Keiser 50: * @author Per Bothner 51: * @author Eric Blake (ebb9@email.byu.edu) 52: * @since 1.1 53: * @status updated to 1.4 54: */ 55: public final class Byte extends Number implements Comparable 56: { 57: /** 58: * Compatible with JDK 1.1+. 59: */ 60: private static final long serialVersionUID = -7183698231559129828L; 61: 62: /** 63: * The minimum value a <code>byte</code> can represent is -128 (or 64: * -2<sup>7</sup>). 65: */ 66: public static final byte MIN_VALUE = -128; 67: 68: /** 69: * The maximum value a <code>byte</code> can represent is 127 (or 70: * 2<sup>7</sup> - 1). 71: */ 72: public static final byte MAX_VALUE = 127; 73: 74: /** 75: * The primitive type <code>byte</code> is represented by this 76: * <code>Class</code> object. 77: */ 78: public static final Class TYPE = VMClassLoader.getPrimitiveClass('B'); 79: 80: /** 81: * The immutable value of this Byte. 82: * 83: * @serial the wrapped byte 84: */ 85: private final byte value; 86: 87: /** 88: * Create a <code>Byte</code> object representing the value of the 89: * <code>byte</code> argument. 90: * 91: * @param value the value to use 92: */ 93: public Byte(byte value) 94: { 95: this.value = value; 96: } 97: 98: /** 99: * Create a <code>Byte</code> object representing the value specified 100: * by the <code>String</code> argument 101: * 102: * @param s the string to convert 103: * @throws NumberFormatException if the String does not contain a byte 104: * @see #valueOf(String) 105: */ 106: public Byte(String s) 107: { 108: value = parseByte(s, 10); 109: } 110: 111: /** 112: * Converts the <code>byte</code> to a <code>String</code> and assumes 113: * a radix of 10. 114: * 115: * @param b the <code>byte</code> to convert to <code>String</code> 116: * @return the <code>String</code> representation of the argument 117: */ 118: public static String toString(byte b) 119: { 120: return String.valueOf(b); 121: } 122: 123: /** 124: * Converts the specified <code>String</code> into a <code>byte</code>. 125: * This function assumes a radix of 10. 126: * 127: * @param s the <code>String</code> to convert 128: * @return the <code>byte</code> value of <code>s</code> 129: * @throws NumberFormatException if <code>s</code> cannot be parsed as a 130: * <code>byte</code> 131: * @see #parseByte(String) 132: */ 133: public static byte parseByte(String s) 134: { 135: return parseByte(s, 10); 136: } 137: 138: /** 139: * Converts the specified <code>String</code> into an <code>int</code> 140: * using the specified radix (base). The string must not be <code>null</code> 141: * or empty. It may begin with an optional '-', which will negate the answer, 142: * provided that there are also valid digits. Each digit is parsed as if by 143: * <code>Character.digit(d, radix)</code>, and must be in the range 144: * <code>0</code> to <code>radix - 1</code>. Finally, the result must be 145: * within <code>MIN_VALUE</code> to <code>MAX_VALUE</code>, inclusive. 146: * Unlike Double.parseDouble, you may not have a leading '+'. 147: * 148: * @param s the <code>String</code> to convert 149: * @param radix the radix (base) to use in the conversion 150: * @return the <code>String</code> argument converted to <code>byte</code> 151: * @throws NumberFormatException if <code>s</code> cannot be parsed as a 152: * <code>byte</code> 153: */ 154: public static byte parseByte(String s, int radix) 155: { 156: int i = Integer.parseInt(s, radix, false); 157: if ((byte) i != i) 158: throw new NumberFormatException(); 159: return (byte) i; 160: } 161: 162: /** 163: * Creates a new <code>Byte</code> object using the <code>String</code> 164: * and specified radix (base). 165: * 166: * @param s the <code>String</code> to convert 167: * @param radix the radix (base) to convert with 168: * @return the new <code>Byte</code> 169: * @throws NumberFormatException if <code>s</code> cannot be parsed as a 170: * <code>byte</code> 171: * @see #parseByte(String, int) 172: */ 173: public static Byte valueOf(String s, int radix) 174: { 175: return new Byte(parseByte(s, radix)); 176: } 177: 178: /** 179: * Creates a new <code>Byte</code> object using the <code>String</code>, 180: * assuming a radix of 10. 181: * 182: * @param s the <code>String</code> to convert 183: * @return the new <code>Byte</code> 184: * @throws NumberFormatException if <code>s</code> cannot be parsed as a 185: * <code>byte</code> 186: * @see #Byte(String) 187: * @see #parseByte(String) 188: */ 189: public static Byte valueOf(String s) 190: { 191: return new Byte(parseByte(s, 10)); 192: } 193: 194: /** 195: * Convert the specified <code>String</code> into a <code>Byte</code>. 196: * The <code>String</code> may represent decimal, hexadecimal, or 197: * octal numbers. 198: * 199: * <p>The extended BNF grammar is as follows:<br> 200: * <pre> 201: * <em>DecodableString</em>: 202: * ( [ <code>-</code> ] <em>DecimalNumber</em> ) 203: * | ( [ <code>-</code> ] ( <code>0x</code> | <code>0X</code> 204: * | <code>#</code> ) { <em>HexDigit</em> }+ ) 205: * | ( [ <code>-</code> ] <code>0</code> { <em>OctalDigit</em> } ) 206: * <em>DecimalNumber</em>: 207: * <em>DecimalDigit except '0'</em> { <em>DecimalDigit</em> } 208: * <em>DecimalDigit</em>: 209: * <em>Character.digit(d, 10) has value 0 to 9</em> 210: * <em>OctalDigit</em>: 211: * <em>Character.digit(d, 8) has value 0 to 7</em> 212: * <em>DecimalDigit</em>: 213: * <em>Character.digit(d, 16) has value 0 to 15</em> 214: * </pre> 215: * Finally, the value must be in the range <code>MIN_VALUE</code> to 216: * <code>MAX_VALUE</code>, or an exception is thrown. 217: * 218: * @param s the <code>String</code> to interpret 219: * @return the value of the String as a <code>Byte</code> 220: * @throws NumberFormatException if <code>s</code> cannot be parsed as a 221: * <code>byte</code> 222: * @throws NullPointerException if <code>s</code> is null 223: * @see Integer#decode(String) 224: */ 225: public static Byte decode(String s) 226: { 227: int i = Integer.parseInt(s, 10, true); 228: if ((byte) i != i) 229: throw new NumberFormatException(); 230: return new Byte((byte) i); 231: } 232: 233: /** 234: * Return the value of this <code>Byte</code>. 235: * 236: * @return the byte value 237: */ 238: public byte byteValue() 239: { 240: return value; 241: } 242: 243: /** 244: * Return the value of this <code>Byte</code> as a <code>short</code>. 245: * 246: * @return the short value 247: */ 248: public short shortValue() 249: { 250: return value; 251: } 252: 253: /** 254: * Return the value of this <code>Byte</code> as an <code>int</code>. 255: * 256: * @return the int value 257: */ 258: public int intValue() 259: { 260: return value; 261: } 262: 263: /** 264: * Return the value of this <code>Byte</code> as a <code>long</code>. 265: * 266: * @return the long value 267: */ 268: public long longValue() 269: { 270: return value; 271: } 272: 273: /** 274: * Return the value of this <code>Byte</code> as a <code>float</code>. 275: * 276: * @return the float value 277: */ 278: public float floatValue() 279: { 280: return value; 281: } 282: 283: /** 284: * Return the value of this <code>Byte</code> as a <code>double</code>. 285: * 286: * @return the double value 287: */ 288: public double doubleValue() 289: { 290: return value; 291: } 292: 293: /** 294: * Converts the <code>Byte</code> value to a <code>String</code> and 295: * assumes a radix of 10. 296: * 297: * @return the <code>String</code> representation of this <code>Byte</code> 298: * @see Integer#toString() 299: */ 300: public String toString() 301: { 302: return String.valueOf(value); 303: } 304: 305: /** 306: * Return a hashcode representing this Object. <code>Byte</code>'s hash 307: * code is simply its value. 308: * 309: * @return this Object's hash code 310: */ 311: public int hashCode() 312: { 313: return value; 314: } 315: 316: /** 317: * Returns <code>true</code> if <code>obj</code> is an instance of 318: * <code>Byte</code> and represents the same byte value. 319: * 320: * @param obj the object to compare 321: * @return whether these Objects are semantically equal 322: */ 323: public boolean equals(Object obj) 324: { 325: return obj instanceof Byte && value == ((Byte) obj).value; 326: } 327: 328: /** 329: * Compare two Bytes numerically by comparing their <code>byte</code> values. 330: * The result is positive if the first is greater, negative if the second 331: * is greater, and 0 if the two are equal. 332: * 333: * @param b the Byte to compare 334: * @return the comparison 335: * @since 1.2 336: */ 337: public int compareTo(Byte b) 338: { 339: return value - b.value; 340: } 341: 342: /** 343: * Behaves like <code>compareTo(Byte)</code> unless the Object 344: * is not a <code>Byte</code>. 345: * 346: * @param o the object to compare 347: * @return the comparison 348: * @throws ClassCastException if the argument is not a <code>Byte</code> 349: * @see #compareTo(Byte) 350: * @see Comparable 351: * @since 1.2 352: */ 353: public int compareTo(Object o) 354: { 355: return compareTo((Byte) o); 356: } 357: }
GNU Classpath (0.18) |