/* Long.java -- object wrapper for long Copyright (C) 1998, 1999, 2001, 2002 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package java.lang; /** * Instances of class Long represent primitive * long values. * * Additionally, this class provides various helper functions and variables * related to longs. * * @author Paul Fisher * @author John Keiser * @author Warren Levy * @author Eric Blake * @since 1.0 * @status updated to 1.4 */ public final class Long extends Number implements Comparable { /** * Compatible with JDK 1.0.2+. */ private static final long serialVersionUID = 4290774380558885855L; /** * The minimum value a long can represent is * -9223372036854775808L (or -263). */ public static final long MIN_VALUE = 0x8000000000000000L; /** * The maximum value a long can represent is * 9223372036854775807 (or 263 - 1). */ public static final long MAX_VALUE = 0x7fffffffffffffffL; /** * The primitive type long is represented by this * Class object. * @since 1.1 */ public static final Class TYPE = VMClassLoader.getPrimitiveClass ('J'); /** * The immutable value of this Long. * * @serial the wrapped long */ private final long value; /** * Create a Long object representing the value of the * long argument. * * @param value the value to use */ public Long(long value) { this.value = value; } /** * Create a Long object representing the value of the * argument after conversion to a long. * * @param s the string to convert * @throws NumberFormatException if the String does not contain a long * @see #valueOf(String) */ public Long(String s) { value = parseLong(s, 10, false); } /** * Converts the long to a String using * the specified radix (base). If the radix exceeds * Character.MIN_RADIX or Character.MAX_RADIX, 10 * is used instead. If the result is negative, the leading character is * '-' ('\\u002D'). The remaining characters come from * Character.forDigit(digit, radix) ('0'-'9','a'-'z'). * * @param num the long to convert to String * @param radix the radix (base) to use in the conversion * @return the String representation of the argument */ public static String toString(long num, int radix) { // Use the Integer toString for efficiency if possible. if ((int) num == num) return Integer.toString((int) num, radix); if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) radix = 10; // For negative numbers, print out the absolute value w/ a leading '-'. // Use an array large enough for a binary number. char[] buffer = new char[65]; int i = 65; boolean isNeg = false; if (num < 0) { isNeg = true; num = -num; // When the value is MIN_VALUE, it overflows when made positive if (num < 0) { buffer[--i] = digits[(int) (-(num + radix) % radix)]; num = -(num / radix); } } do { buffer[--i] = digits[(int) (num % radix)]; num /= radix; } while (num > 0); if (isNeg) buffer[--i] = '-'; // Package constructor avoids an array copy. return new String(buffer, i, 65 - i, true); } /** * Converts the long to a String assuming it is * unsigned in base 16. * * @param l the long to convert to String * @return the String representation of the argument */ public static String toHexString(long l) { return toUnsignedString(l, 4); } /** * Converts the long to a String assuming it is * unsigned in base 8. * * @param l the long to convert to String * @return the String representation of the argument */ public static String toOctalString(long l) { return toUnsignedString(l, 3); } /** * Converts the long to a String assuming it is * unsigned in base 2. * * @param l the long to convert to String * @return the String representation of the argument */ public static String toBinaryString(long l) { return toUnsignedString(l, 1); } /** * Converts the long to a String and assumes * a radix of 10. * * @param num the long to convert to String * @return the String representation of the argument * @see #toString(long, int) */ public static String toString(long num) { return toString(num, 10); } /** * Converts the specified String into an int * using the specified radix (base). The string must not be null * or empty. It may begin with an optional '-', which will negate the answer, * provided that there are also valid digits. Each digit is parsed as if by * Character.digit(d, radix), and must be in the range * 0 to radix - 1. Finally, the result must be * within MIN_VALUE to MAX_VALUE, inclusive. * Unlike Double.parseDouble, you may not have a leading '+'; and 'l' or * 'L' as the last character is only valid in radices 22 or greater, where * it is a digit and not a type indicator. * * @param s the String to convert * @param radix the radix (base) to use in the conversion * @return the String argument converted to long * @throws NumberFormatException if s cannot be parsed as a * long */ public static long parseLong(String str, int radix) { return parseLong(str, radix, false); } /** * Converts the specified String into a long. * This function assumes a radix of 10. * * @param s the String to convert * @return the int value of s * @throws NumberFormatException if s cannot be parsed as a * long * @see #parseLong(String, int) */ public static long parseLong(String s) { return parseLong(s, 10, false); } /** * Creates a new Long object using the String * and specified radix (base). * * @param s the String to convert * @param radix the radix (base) to convert with * @return the new Long * @throws NumberFormatException if s cannot be parsed as a * long * @see #parseLong(String, int) */ public static Long valueOf(String s, int radix) { return new Long(parseLong(s, radix, false)); } /** * Creates a new Long object using the String, * assuming a radix of 10. * * @param s the String to convert * @return the new Long * @throws NumberFormatException if s cannot be parsed as a * long * @see #Long(String) * @see #parseLong(String) */ public static Long valueOf(String s) { return new Long(parseLong(s, 10, false)); } /** * Convert the specified String into a Long. * The String may represent decimal, hexadecimal, or * octal numbers. * *

The extended BNF grammar is as follows:
*

   * DecodableString:
   *      ( [ - ] DecimalNumber )
   *    | ( [ - ] ( 0x | 0X
   *              | # ) HexDigit { HexDigit } )
   *    | ( [ - ] 0 { OctalDigit } )
   * DecimalNumber:
   *        DecimalDigit except '0' { DecimalDigit }
   * DecimalDigit:
   *        Character.digit(d, 10) has value 0 to 9
   * OctalDigit:
   *        Character.digit(d, 8) has value 0 to 7
   * DecimalDigit:
   *        Character.digit(d, 16) has value 0 to 15
   * 
* Finally, the value must be in the range MIN_VALUE to * MAX_VALUE, or an exception is thrown. Note that you cannot * use a trailing 'l' or 'L', unlike in Java source code. * * @param s the String to interpret * @return the value of the String as a Long * @throws NumberFormatException if s cannot be parsed as a * long * @throws NullPointerException if s is null * @since 1.2 */ public static Long decode(String str) { return new Long(parseLong(str, 10, true)); } /** * Return the value of this Long as a byte. * * @return the byte value */ public byte byteValue() { return (byte) value; } /** * Return the value of this Long as a short. * * @return the short value */ public short shortValue() { return (short) value; } /** * Return the value of this Long as an int. * * @return the int value */ public int intValue() { return (int) value; } /** * Return the value of this Long. * * @return the long value */ public long longValue() { return value; } /** * Return the value of this Long as a float. * * @return the float value */ public float floatValue() { return value; } /** * Return the value of this Long as a double. * * @return the double value */ public double doubleValue() { return value; } /** * Converts the Long value to a String and * assumes a radix of 10. * * @return the String representation */ public String toString() { return toString(value, 10); } /** * Return a hashcode representing this Object. Long's hash * code is calculated by (int) (value ^ (value >> 32)). * * @return this Object's hash code */ public int hashCode() { return (int) (value ^ (value >>> 32)); } /** * Returns true if obj is an instance of * Long and represents the same long value. * * @param obj the object to compare * @return whether these Objects are semantically equal */ public boolean equals(Object obj) { return obj instanceof Long && value == ((Long) obj).value; } /** * Get the specified system property as a Long. The * decode() method will be used to interpret the value of * the property. * * @param nm the name of the system property * @return the system property as a Long, or null if the * property is not found or cannot be decoded * @throws SecurityException if accessing the system property is forbidden * @see System#getProperty(String) * @see #decode(String) */ public static Long getLong(String nm) { return getLong(nm, null); } /** * Get the specified system property as a Long, or use a * default long value if the property is not found or is not * decodable. The decode() method will be used to interpret * the value of the property. * * @param nm the name of the system property * @param val the default value * @return the value of the system property, or the default * @throws SecurityException if accessing the system property is forbidden * @see System#getProperty(String) * @see #decode(String) */ public static Long getLong(String nm, long val) { Long result = getLong(nm, null); return result == null ? new Long(val) : result; } /** * Get the specified system property as a Long, or use a * default Long value if the property is not found or is * not decodable. The decode() method will be used to * interpret the value of the property. * * @param nm the name of the system property * @param val the default value * @return the value of the system property, or the default * @throws SecurityException if accessing the system property is forbidden * @see System#getProperty(String) * @see #decode(String) */ public static Long getLong(String nm, Long def) { if (nm == null || "".equals(nm)) return def; nm = System.getProperty(nm); if (nm == null) return def; try { return decode(nm); } catch (NumberFormatException e) { return def; } } /** * Compare two Longs numerically by comparing their long * values. The result is positive if the first is greater, negative if the * second is greater, and 0 if the two are equal. * * @param l the Long to compare * @return the comparison * @since 1.2 */ public int compareTo(Long l) { if (value == l.value) return 0; // Returns just -1 or 1 on inequality; doing math might overflow the long. return value > l.value ? 1 : -1; } /** * Behaves like compareTo(Long) unless the Object * is not a Long. * * @param o the object to compare * @return the comparison * @throws ClassCastException if the argument is not a Long * @see #compareTo(Long) * @see Comparable * @since 1.2 */ public int compareTo(Object o) { return compareTo((Long) o); } /** * Helper for converting unsigned numbers to String. * * @param num the number * @param exp log2(digit) (ie. 1, 3, or 4 for binary, oct, hex) */ private static String toUnsignedString(long num, int exp) { // Use the Integer toUnsignedString for efficiency if possible. // If NUM<0 then this particular optimization doesn't work // properly. if (num >= 0 && (int) num == num) return Integer.toUnsignedString((int) num, exp); // Use an array large enough for a binary number. int mask = (1 << exp) - 1; char[] buffer = new char[64]; int i = 64; do { buffer[--i] = digits[(int) num & mask]; num >>>= exp; } while (num != 0); // Package constructor avoids an array copy. return new String(buffer, i, 64 - i, true); } /** * Helper for parsing longs. * * @param str the string to parse * @param radix the radix to use, must be 10 if decode is true * @param decode if called from decode * @return the parsed long value * @throws NumberFormatException if there is an error * @throws NullPointerException if decode is true and str is null * @see #parseLong(String, int) * @see #decode(String) */ private static long parseLong(String str, int radix, boolean decode) { if (! decode && str == null) throw new NumberFormatException(); int index = 0; int len = str.length(); boolean isNeg = false; if (len == 0) throw new NumberFormatException(); int ch = str.charAt(index); if (ch == '-') { if (len == 1) throw new NumberFormatException(); isNeg = true; ch = str.charAt(++index); } if (decode) { if (ch == '0') { if (++index == len) return 0; if ((str.charAt(index) & ~('x' ^ 'X')) == 'X') { radix = 16; index++; } else radix = 8; } else if (ch == '#') { radix = 16; index++; } } if (index == len) throw new NumberFormatException(); long max = MAX_VALUE / radix; // We can't directly write `max = (MAX_VALUE + 1) / radix'. // So instead we fake it. if (isNeg && MAX_VALUE % radix == radix - 1) ++max; long val = 0; while (index < len) { if (val < 0 || val > max) throw new NumberFormatException(); ch = Character.digit(str.charAt(index++), radix); val = val * radix + ch; if (ch < 0 || (val < 0 && (! isNeg || val != MIN_VALUE))) throw new NumberFormatException(); } return isNeg ? -val : val; } }