| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package java.lang; |
| |
| /** |
| * The wrapper for the primitive type {@code long}. |
| * <p> |
| * Implementation note: The "bit twiddling" methods in this class use techniques |
| * described in <a href="http://www.hackersdelight.org/">Henry S. Warren, |
| * Jr.'s Hacker's Delight, (Addison Wesley, 2002)</a> and <a href= |
| * "http://graphics.stanford.edu/~seander/bithacks.html">Sean Anderson's |
| * Bit Twiddling Hacks.</a> |
| * |
| * @see java.lang.Integer |
| * @since 1.0 |
| */ |
| @FindBugsSuppressWarnings("DM_NUMBER_CTOR") |
| public final class Long extends Number implements Comparable<Long> { |
| |
| private static final long serialVersionUID = 4290774380558885855L; |
| |
| /** |
| * The value which the receiver represents. |
| */ |
| private final long value; |
| |
| /** |
| * Constant for the maximum {@code long} value, 2<sup>63</sup>-1. |
| */ |
| public static final long MAX_VALUE = 0x7FFFFFFFFFFFFFFFL; |
| |
| /** |
| * Constant for the minimum {@code long} value, -2<sup>63</sup>. |
| */ |
| public static final long MIN_VALUE = 0x8000000000000000L; |
| |
| /** |
| * The {@link Class} object that represents the primitive type {@code long}. |
| */ |
| @SuppressWarnings("unchecked") |
| public static final Class<Long> TYPE |
| = (Class<Long>) long[].class.getComponentType(); |
| // Note: Long.TYPE can't be set to "long.class", since *that* is |
| // defined to be "java.lang.Long.TYPE"; |
| |
| /** |
| * Constant for the number of bits needed to represent a {@code long} in |
| * two's complement form. |
| * |
| * @since 1.5 |
| */ |
| public static final int SIZE = 64; |
| |
| /** |
| * Constructs a new {@code Long} with the specified primitive long value. |
| * |
| * @param value |
| * the primitive long value to store in the new instance. |
| */ |
| public Long(long value) { |
| this.value = value; |
| } |
| |
| /** |
| * Constructs a new {@code Long} from the specified string. |
| * |
| * @param string |
| * the string representation of a long value. |
| * @throws NumberFormatException |
| * if {@code string} cannot be parsed as a long value. |
| * @see #parseLong(String) |
| */ |
| public Long(String string) throws NumberFormatException { |
| this(parseLong(string)); |
| } |
| |
| @Override |
| public byte byteValue() { |
| return (byte) value; |
| } |
| |
| /** |
| * Compares this object to the specified long object to determine their |
| * relative order. |
| * |
| * @param object |
| * the long object to compare this object to. |
| * @return a negative value if the value of this long is less than the value |
| * of {@code object}; 0 if the value of this long and the value of |
| * {@code object} are equal; a positive value if the value of this |
| * long is greater than the value of {@code object}. |
| * @see java.lang.Comparable |
| * @since 1.2 |
| */ |
| public int compareTo(Long object) { |
| return compare(value, object.value); |
| } |
| |
| /** |
| * Compares two {@code long} values. |
| * @return 0 if lhs = rhs, less than 0 if lhs < rhs, and greater than 0 if lhs > rhs. |
| * @since 1.7 |
| * @hide 1.7 |
| */ |
| public static int compare(long lhs, long rhs) { |
| return lhs < rhs ? -1 : (lhs == rhs ? 0 : 1); |
| } |
| |
| private static NumberFormatException invalidLong(String s) { |
| throw new NumberFormatException("Invalid long: \"" + s + "\""); |
| } |
| |
| /** |
| * Parses the specified string and returns a {@code Long} instance if the |
| * string can be decoded into a long value. The string may be an optional |
| * minus sign "-" followed by a hexadecimal ("0x..." or "#..."), octal |
| * ("0..."), or decimal ("...") representation of a long. |
| * |
| * @param string |
| * a string representation of a long value. |
| * @return a {@code Long} containing the value represented by {@code string}. |
| * @throws NumberFormatException |
| * if {@code string} cannot be parsed as a long value. |
| */ |
| public static Long decode(String string) throws NumberFormatException { |
| int length = string.length(), i = 0; |
| if (length == 0) { |
| throw invalidLong(string); |
| } |
| char firstDigit = string.charAt(i); |
| boolean negative = firstDigit == '-'; |
| if (negative) { |
| if (length == 1) { |
| throw invalidLong(string); |
| } |
| firstDigit = string.charAt(++i); |
| } |
| |
| int base = 10; |
| if (firstDigit == '0') { |
| if (++i == length) { |
| return valueOf(0L); |
| } |
| if ((firstDigit = string.charAt(i)) == 'x' || firstDigit == 'X') { |
| if (i == length) { |
| throw invalidLong(string); |
| } |
| i++; |
| base = 16; |
| } else { |
| base = 8; |
| } |
| } else if (firstDigit == '#') { |
| if (i == length) { |
| throw invalidLong(string); |
| } |
| i++; |
| base = 16; |
| } |
| |
| long result = parse(string, i, base, negative); |
| return valueOf(result); |
| } |
| |
| @Override |
| public double doubleValue() { |
| return value; |
| } |
| |
| /** |
| * Compares this instance with the specified object and indicates if they |
| * are equal. In order to be equal, {@code o} must be an instance of |
| * {@code Long} and have the same long value as this object. |
| * |
| * @param o |
| * the object to compare this long with. |
| * @return {@code true} if the specified object is equal to this |
| * {@code Long}; {@code false} otherwise. |
| */ |
| @Override |
| public boolean equals(Object o) { |
| return (o instanceof Long) && (((Long) o).value == value); |
| } |
| |
| @Override |
| public float floatValue() { |
| return value; |
| } |
| |
| /** |
| * Returns the {@code Long} value of the system property identified by |
| * {@code string}. Returns {@code null} if {@code string} is {@code null} |
| * or empty, if the property can not be found or if its value can not be |
| * parsed as a long. |
| * |
| * @param string |
| * the name of the requested system property. |
| * @return the requested property's value as a {@code Long} or {@code null}. |
| */ |
| public static Long getLong(String string) { |
| if (string == null || string.length() == 0) { |
| return null; |
| } |
| String prop = System.getProperty(string); |
| if (prop == null) { |
| return null; |
| } |
| try { |
| return decode(prop); |
| } catch (NumberFormatException ex) { |
| return null; |
| } |
| } |
| |
| /** |
| * Returns the {@code Long} value of the system property identified by |
| * {@code string}. Returns the specified default value if {@code string} is |
| * {@code null} or empty, if the property can not be found or if its value |
| * can not be parsed as a long. |
| * |
| * @param string |
| * the name of the requested system property. |
| * @param defaultValue |
| * the default value that is returned if there is no long system |
| * property with the requested name. |
| * @return the requested property's value as a {@code Long} or the default |
| * value. |
| */ |
| public static Long getLong(String string, long defaultValue) { |
| if (string == null || string.length() == 0) { |
| return valueOf(defaultValue); |
| } |
| String prop = System.getProperty(string); |
| if (prop == null) { |
| return valueOf(defaultValue); |
| } |
| try { |
| return decode(prop); |
| } catch (NumberFormatException ex) { |
| return valueOf(defaultValue); |
| } |
| } |
| |
| /** |
| * Returns the {@code Long} value of the system property identified by |
| * {@code string}. Returns the specified default value if {@code string} is |
| * {@code null} or empty, if the property can not be found or if its value |
| * can not be parsed as a long. |
| * |
| * @param string |
| * the name of the requested system property. |
| * @param defaultValue |
| * the default value that is returned if there is no long system |
| * property with the requested name. |
| * @return the requested property's value as a {@code Long} or the default |
| * value. |
| */ |
| public static Long getLong(String string, Long defaultValue) { |
| if (string == null || string.length() == 0) { |
| return defaultValue; |
| } |
| String prop = System.getProperty(string); |
| if (prop == null) { |
| return defaultValue; |
| } |
| try { |
| return decode(prop); |
| } catch (NumberFormatException ex) { |
| return defaultValue; |
| } |
| } |
| |
| @Override |
| public int hashCode() { |
| return (int) (value ^ (value >>> 32)); |
| } |
| |
| @Override |
| public int intValue() { |
| return (int) value; |
| } |
| |
| /** |
| * Gets the primitive value of this long. |
| * |
| * @return this object's primitive value. |
| */ |
| @Override |
| public long longValue() { |
| return value; |
| } |
| |
| /** |
| * Parses the specified string as a signed decimal long value. The ASCII |
| * character \u002d ('-') is recognized as the minus sign. |
| * |
| * @param string |
| * the string representation of a long value. |
| * @return the primitive long value represented by {@code string}. |
| * @throws NumberFormatException |
| * if {@code string} cannot be parsed as a long value. |
| */ |
| public static long parseLong(String string) throws NumberFormatException { |
| return parseLong(string, 10); |
| } |
| |
| /** |
| * Parses the specified string as a signed long value using the specified |
| * radix. The ASCII character \u002d ('-') is recognized as the minus sign. |
| * |
| * @param string |
| * the string representation of a long value. |
| * @param radix |
| * the radix to use when parsing. |
| * @return the primitive long value represented by {@code string} using |
| * {@code radix}. |
| * @throws NumberFormatException |
| * if {@code string} cannot be parsed as a long value, or |
| * {@code radix < Character.MIN_RADIX || |
| * radix > Character.MAX_RADIX}. |
| */ |
| public static long parseLong(String string, int radix) throws NumberFormatException { |
| if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) { |
| throw new NumberFormatException("Invalid radix: " + radix); |
| } |
| if (string == null) { |
| throw invalidLong(string); |
| } |
| int length = string.length(), i = 0; |
| if (length == 0) { |
| throw invalidLong(string); |
| } |
| boolean negative = string.charAt(i) == '-'; |
| if (negative && ++i == length) { |
| throw invalidLong(string); |
| } |
| |
| return parse(string, i, radix, negative); |
| } |
| |
| private static long parse(String string, int offset, int radix, boolean negative) { |
| long max = Long.MIN_VALUE / radix; |
| long result = 0, length = string.length(); |
| while (offset < length) { |
| int digit = Character.digit(string.charAt(offset++), radix); |
| if (digit == -1) { |
| throw invalidLong(string); |
| } |
| if (max > result) { |
| throw invalidLong(string); |
| } |
| long next = result * radix - digit; |
| if (next > result) { |
| throw invalidLong(string); |
| } |
| result = next; |
| } |
| if (!negative) { |
| result = -result; |
| if (result < 0) { |
| throw invalidLong(string); |
| } |
| } |
| return result; |
| } |
| |
| @Override |
| public short shortValue() { |
| return (short) value; |
| } |
| |
| /** |
| * Converts the specified long value into its binary string representation. |
| * The returned string is a concatenation of '0' and '1' characters. |
| * |
| * @param v |
| * the long value to convert. |
| * @return the binary string representation of {@code v}. |
| */ |
| public static String toBinaryString(long v) { |
| return IntegralToString.longToBinaryString(v); |
| } |
| |
| /** |
| * Converts the specified long value into its hexadecimal string |
| * representation. The returned string is a concatenation of characters from |
| * '0' to '9' and 'a' to 'f'. |
| * |
| * @param v |
| * the long value to convert. |
| * @return the hexadecimal string representation of {@code l}. |
| */ |
| public static String toHexString(long v) { |
| return IntegralToString.longToHexString(v); |
| } |
| |
| /** |
| * Converts the specified long value into its octal string representation. |
| * The returned string is a concatenation of characters from '0' to '7'. |
| * |
| * @param v |
| * the long value to convert. |
| * @return the octal string representation of {@code l}. |
| */ |
| public static String toOctalString(long v) { |
| return IntegralToString.longToOctalString(v); |
| } |
| |
| @Override |
| public String toString() { |
| return Long.toString(value); |
| } |
| |
| /** |
| * Converts the specified long value into its decimal string representation. |
| * The returned string is a concatenation of a minus sign if the number is |
| * negative and characters from '0' to '9'. |
| * |
| * @param n |
| * the long to convert. |
| * @return the decimal string representation of {@code l}. |
| */ |
| public static String toString(long n) { |
| return IntegralToString.longToString(n); |
| } |
| |
| /** |
| * Converts the specified signed long value into a string representation based on |
| * the specified radix. The returned string is a concatenation of a minus |
| * sign if the number is negative and characters from '0' to '9' and 'a' to |
| * 'z', depending on the radix. If {@code radix} is not in the interval |
| * defined by {@code Character.MIN_RADIX} and {@code Character.MAX_RADIX} |
| * then 10 is used as the base for the conversion. |
| * |
| * <p>This method treats its argument as signed. If you want to convert an |
| * unsigned value to one of the common non-decimal bases, you may find |
| * {@link #toBinaryString}, {@code #toHexString}, or {@link #toOctalString} |
| * more convenient. |
| * |
| * @param v |
| * the signed long to convert. |
| * @param radix |
| * the base to use for the conversion. |
| * @return the string representation of {@code v}. |
| */ |
| public static String toString(long v, int radix) { |
| return IntegralToString.longToString(v, radix); |
| } |
| |
| /** |
| * Parses the specified string as a signed decimal long value. |
| * |
| * @param string |
| * the string representation of a long value. |
| * @return a {@code Long} instance containing the long value represented by |
| * {@code string}. |
| * @throws NumberFormatException |
| * if {@code string} cannot be parsed as a long value. |
| * @see #parseLong(String) |
| */ |
| public static Long valueOf(String string) throws NumberFormatException { |
| return valueOf(parseLong(string)); |
| } |
| |
| /** |
| * Parses the specified string as a signed long value using the specified |
| * radix. |
| * |
| * @param string |
| * the string representation of a long value. |
| * @param radix |
| * the radix to use when parsing. |
| * @return a {@code Long} instance containing the long value represented by |
| * {@code string} using {@code radix}. |
| * @throws NumberFormatException |
| * if {@code string} cannot be parsed as a long value, or |
| * {@code radix < Character.MIN_RADIX || |
| * radix > Character.MAX_RADIX}. |
| * @see #parseLong(String, int) |
| */ |
| public static Long valueOf(String string, int radix) throws NumberFormatException { |
| return valueOf(parseLong(string, radix)); |
| } |
| |
| /** |
| * Determines the highest (leftmost) bit of the specified long value that is |
| * 1 and returns the bit mask value for that bit. This is also referred to |
| * as the Most Significant 1 Bit. Returns zero if the specified long is |
| * zero. |
| * |
| * @param v |
| * the long to examine. |
| * @return the bit mask indicating the highest 1 bit in {@code v}. |
| * @since 1.5 |
| */ |
| public static long highestOneBit(long v) { |
| // Hacker's Delight, Figure 3-1 |
| v |= (v >> 1); |
| v |= (v >> 2); |
| v |= (v >> 4); |
| v |= (v >> 8); |
| v |= (v >> 16); |
| v |= (v >> 32); |
| return v - (v >>> 1); |
| } |
| |
| /** |
| * Determines the lowest (rightmost) bit of the specified long value that is |
| * 1 and returns the bit mask value for that bit. This is also referred to |
| * as the Least Significant 1 Bit. Returns zero if the specified long is |
| * zero. |
| * |
| * @param v |
| * the long to examine. |
| * @return the bit mask indicating the lowest 1 bit in {@code v}. |
| * @since 1.5 |
| */ |
| public static long lowestOneBit(long v) { |
| return v & -v; |
| } |
| |
| /** |
| * Determines the number of leading zeros in the specified long value prior |
| * to the {@link #highestOneBit(long) highest one bit}. |
| * |
| * @param v |
| * the long to examine. |
| * @return the number of leading zeros in {@code v}. |
| * @since 1.5 |
| */ |
| public static int numberOfLeadingZeros(long v) { |
| // After Hacker's Delight, Figure 5-6 |
| if (v < 0) { |
| return 0; |
| } |
| if (v == 0) { |
| return 64; |
| } |
| // On a 64-bit VM, the two previous tests should probably be replaced by |
| // if (v <= 0) return ((int) (~v >> 57)) & 64; |
| |
| int n = 1; |
| int i = (int) (v >>> 32); |
| if (i == 0) { |
| n += 32; |
| i = (int) v; |
| } |
| if (i >>> 16 == 0) { |
| n += 16; |
| i <<= 16; |
| } |
| if (i >>> 24 == 0) { |
| n += 8; |
| i <<= 8; |
| } |
| if (i >>> 28 == 0) { |
| n += 4; |
| i <<= 4; |
| } |
| if (i >>> 30 == 0) { |
| n += 2; |
| i <<= 2; |
| } |
| return n - (i >>> 31); |
| } |
| |
| /** |
| * Determines the number of trailing zeros in the specified long value after |
| * the {@link #lowestOneBit(long) lowest one bit}. |
| * |
| * @param v |
| * the long to examine. |
| * @return the number of trailing zeros in {@code v}. |
| * @since 1.5 |
| */ |
| public static int numberOfTrailingZeros(long v) { |
| int low = (int) v; |
| return low !=0 ? Integer.numberOfTrailingZeros(low) |
| : 32 + Integer.numberOfTrailingZeros((int) (v >>> 32)); |
| } |
| |
| /** |
| * Counts the number of 1 bits in the specified long value; this is also |
| * referred to as population count. |
| * |
| * @param v |
| * the long to examine. |
| * @return the number of 1 bits in {@code v}. |
| * @since 1.5 |
| */ |
| public static int bitCount(long v) { |
| // Combines techniques from several sources |
| v -= (v >>> 1) & 0x5555555555555555L; |
| v = (v & 0x3333333333333333L) + ((v >>> 2) & 0x3333333333333333L); |
| int i = ((int)(v >>> 32)) + (int) v; |
| i = (i & 0x0F0F0F0F) + ((i >>> 4) & 0x0F0F0F0F); |
| i += i >>> 8; |
| i += i >>> 16; |
| return i & 0x0000007F; |
| } |
| |
| /* |
| * On a modern 64-bit processor with a fast hardware multiply, this is |
| * much faster (assuming you're running a 64-bit VM): |
| * |
| * // http://chessprogramming.wikispaces.com/Population+Count |
| * int bitCount (long x) { |
| * x -= (x >>> 1) & 0x5555555555555555L; |
| * x = (x & 0x3333333333333333L) + ((x >>> 2) & 0x3333333333333333L); |
| * x = (x + (x >>> 4)) & 0x0f0f0f0f0f0f0f0fL; |
| * x = (x * 0x0101010101010101L) >>> 56; |
| * return (int) x; |
| * } |
| * |
| * Really modern processors (e.g., Nehalem, K-10) have hardware popcount |
| * instructions. |
| */ |
| |
| /** |
| * Rotates the bits of the specified long value to the left by the specified |
| * number of bits. |
| * |
| * @param v |
| * the long value to rotate left. |
| * @param distance |
| * the number of bits to rotate. |
| * @return the rotated value. |
| * @since 1.5 |
| */ |
| public static long rotateLeft(long v, int distance) { |
| // Shift distances are mod 64 (JLS3 15.19), so we needn't mask -distance |
| return (v << distance) | (v >>> -distance); |
| } |
| |
| /** |
| * Rotates the bits of the specified long value to the right by the |
| * specified number of bits. |
| * |
| * @param v |
| * the long value to rotate right. |
| * @param distance |
| * the number of bits to rotate. |
| * @return the rotated value. |
| * @since 1.5 |
| */ |
| public static long rotateRight(long v, int distance) { |
| // Shift distances are mod 64 (JLS3 15.19), so we needn't mask -distance |
| return (v >>> distance) | (v << -distance); |
| } |
| |
| /** |
| * Reverses the order of the bytes of the specified long value. |
| * |
| * @param v |
| * the long value for which to reverse the byte order. |
| * @return the reversed value. |
| * @since 1.5 |
| */ |
| public static long reverseBytes(long v) { |
| // Hacker's Delight 7-1, with minor tweak from Veldmeijer |
| // http://graphics.stanford.edu/~seander/bithacks.html |
| v = ((v >>> 8) & 0x00FF00FF00FF00FFL) | ((v & 0x00FF00FF00FF00FFL) << 8); |
| v = ((v >>>16) & 0x0000FFFF0000FFFFL) | ((v & 0x0000FFFF0000FFFFL) <<16); |
| return ((v >>>32) ) | ((v ) <<32); |
| } |
| |
| /** |
| * Reverses the order of the bits of the specified long value. |
| * |
| * @param v |
| * the long value for which to reverse the bit order. |
| * @return the reversed value. |
| * @since 1.5 |
| */ |
| public static long reverse(long v) { |
| // Hacker's Delight 7-1, with minor tweak from Veldmeijer |
| // http://graphics.stanford.edu/~seander/bithacks.html |
| v = ((v >>> 1) & 0x5555555555555555L) | ((v & 0x5555555555555555L) << 1); |
| v = ((v >>> 2) & 0x3333333333333333L) | ((v & 0x3333333333333333L) << 2); |
| v = ((v >>> 4) & 0x0F0F0F0F0F0F0F0FL) | ((v & 0x0F0F0F0F0F0F0F0FL) << 4); |
| v = ((v >>> 8) & 0x00FF00FF00FF00FFL) | ((v & 0x00FF00FF00FF00FFL) << 8); |
| v = ((v >>>16) & 0x0000FFFF0000FFFFL) | ((v & 0x0000FFFF0000FFFFL) <<16); |
| return ((v >>>32) ) | ((v ) <<32); |
| } |
| |
| /** |
| * Returns the value of the {@code signum} function for the specified long |
| * value. |
| * |
| * @param v |
| * the long value to check. |
| * @return -1 if {@code v} is negative, 1 if {@code v} is positive, 0 if |
| * {@code v} is zero. |
| * @since 1.5 |
| */ |
| public static int signum(long v) { |
| return v < 0 ? -1 : (v == 0 ? 0 : 1); |
| } |
| |
| /** |
| * Returns a {@code Long} instance for the specified long value. |
| * <p> |
| * If it is not necessary to get a new {@code Long} instance, it is |
| * recommended to use this method instead of the constructor, since it |
| * maintains a cache of instances which may result in better performance. |
| * |
| * @param v |
| * the long value to store in the instance. |
| * @return a {@code Long} instance containing {@code v}. |
| * @since 1.5 |
| */ |
| public static Long valueOf(long v) { |
| return v >= 128 || v < -128 ? new Long(v) : SMALL_VALUES[((int) v) + 128]; |
| } |
| |
| /** |
| * A cache of instances used by {@link Long#valueOf(long)} and auto-boxing. |
| */ |
| private static final Long[] SMALL_VALUES = new Long[256]; |
| |
| static { |
| for (int i = -128; i < 128; i++) { |
| SMALL_VALUES[i + 128] = new Long(i); |
| } |
| } |
| } |