/*
* 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>
* As with the specification, this implementation relies on code laid out in <a
* href="http://www.hackersdelight.org/">Henry S. Warren, Jr.'s Hacker's
* Delight, (Addison Wesley, 2002)</a> as well as <a
* href="http://aggregate.org/MAGIC/">The Aggregate's Magic Algorithms</a>.
* </p>
*
* @see java.lang.Number
* @since Android 1.0
*/
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.
*
* @since Android 1.0
*/
public static final long MAX_VALUE = 0x7FFFFFFFFFFFFFFFL;
/**
* Constant for the minimum {@code long} value, -2<sup>63</sup>.
*
* @since Android 1.0
*/
public static final long MIN_VALUE = 0x8000000000000000L;
/**
* The {@link Class} object that represents the primitive type {@code long}.
*
* @since Android 1.0
*/
@SuppressWarnings("unchecked")
public static final Class<Long> TYPE = (Class<Long>) new long[0].getClass()
.getComponentType();
// Note: This 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 Android 1.0
*/
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.
* @since Android 1.0
*/
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} can not be decoded into a long value.
* @see #parseLong(String)
* @since Android 1.0
*/
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 Android 1.0
*/
public int compareTo(Long object) {
return value > object.value ? 1 : (value < object.value ? -1 : 0);
}
/**
* 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} can not be parsed as a long value.
* @since Android 1.0
*/
public static Long decode(String string) throws NumberFormatException {
int length = string.length(), i = 0;
if (length == 0) {
throw new NumberFormatException();
}
char firstDigit = string.charAt(i);
boolean negative = firstDigit == '-';
if (negative) {
if (length == 1) {
throw new NumberFormatException(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 new NumberFormatException(string);
}
i++;
base = 16;
} else {
base = 8;
}
} else if (firstDigit == '#') {
if (i == length) {
throw new NumberFormatException(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.
* @since Android 1.0
*/
@Override
public boolean equals(Object o) {
return (o instanceof Long)
&& (value == ((Long) o).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}.
* @since Android 1.0
*/
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.
* @since Android 1.0
*/
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.
* @since Android 1.0
*/
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.
* @since Android 1.0
*/
@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} is {@code null}, has a length of zero or
* can not be parsed as a long value.
* @since Android 1.0
*/
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} is {@code null} or has a length of zero,
* {@code radix < Character.MIN_RADIX},
* {@code radix > Character.MAX_RADIX}, or if {@code string}
* can not be parsed as a long value.
* @since Android 1.0
*/
public static long parseLong(String string, int radix)
throws NumberFormatException {
if (string == null || radix < Character.MIN_RADIX
|| radix > Character.MAX_RADIX) {
throw new NumberFormatException();
}
int length = string.length(), i = 0;
if (length == 0) {
throw new NumberFormatException(string);
}
boolean negative = string.charAt(i) == '-';
if (negative && ++i == length) {
throw new NumberFormatException(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 new NumberFormatException(string);
}
if (max > result) {
throw new NumberFormatException(string);
}
long next = result * radix - digit;
if (next > result) {
throw new NumberFormatException(string);
}
result = next;
}
if (!negative) {
result = -result;
if (result < 0) {
throw new NumberFormatException(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 l
* the long value to convert.
* @return the binary string representation of {@code l}.
* @since Android 1.0
*/
public static String toBinaryString(long l) {
int count = 1;
long j = l;
if (l < 0) {
count = 64;
} else {
while ((j >>= 1) != 0) {
count++;
}
}
char[] buffer = new char[count];
do {
buffer[--count] = (char) ((l & 1) + '0');
l >>= 1;
} while (count > 0);
return new String(0, buffer.length, buffer);
}
/**
* 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 l
* the long value to convert.
* @return the hexadecimal string representation of {@code l}.
* @since Android 1.0
*/
public static String toHexString(long l) {
int count = 1;
long j = l;
if (l < 0) {
count = 16;
} else {
while ((j >>= 4) != 0) {
count++;
}
}
char[] buffer = new char[count];
do {
int t = (int) (l & 15);
if (t > 9) {
t = t - 10 + 'a';
} else {
t += '0';
}
buffer[--count] = (char) t;
l >>= 4;
} while (count > 0);
return new String(0, buffer.length, buffer);
}
/**
* Converts the specified long value into its octal string representation.
* The returned string is a concatenation of characters from '0' to '7'.
*
* @param l
* the long value to convert.
* @return the octal string representation of {@code l}.
* @since Android 1.0
*/
public static String toOctalString(long l) {
int count = 1;
long j = l;
if (l < 0) {
count = 22;
} else {
while ((j >>>= 3) != 0) {
count++;
}
}
char[] buffer = new char[count];
do {
buffer[--count] = (char) ((l & 7) + '0');
l >>>= 3;
} while (count > 0);
return new String(0, buffer.length, buffer);
}
@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 l
* the long to convert.
* @return the decimal string representation of {@code l}.
* @since Android 1.0
*/
public static String toString(long l) {
return toString(l, 10);
}
/**
* Converts the specified 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.
*
* @param l
* the long to convert.
* @param radix
* the base to use for the conversion.
* @return the string representation of {@code l}.
* @since Android 1.0
*/
public static String toString(long l, int radix) {
if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
radix = 10;
}
if (l == 0) {
return "0"; //$NON-NLS-1$
}
int count = 2;
long j = l;
boolean negative = l < 0;
if (!negative) {
count = 1;
j = -l;
}
while ((l /= radix) != 0) {
count++;
}
char[] buffer = new char[count];
do {
int ch = 0 - (int) (j % radix);
if (ch > 9) {
ch = ch - 10 + 'a';
} else {
ch += '0';
}
buffer[--count] = (char) ch;
} while ((j /= radix) != 0);
if (negative) {
buffer[0] = '-';
}
return new String(0, buffer.length, buffer);
}
/**
* 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} is {@code null}, has a length of zero or
* can not be parsed as a long value.
* @see #parseLong(String)
* @since Android 1.0
*/
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} is {@code null} or has a length of zero,
* {@code radix < Character.MIN_RADIX},
* {@code radix > Character.MAX_RADIX}, or if {@code string}
* can not be parsed as a long value.
* @see #parseLong(String, int)
* @since Android 1.0
*/
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 lng
* the long to examine.
* @return the bit mask indicating the highest 1 bit in {@code lng}.
* @since Android 1.0
*/
public static long highestOneBit(long lng) {
lng |= (lng >> 1);
lng |= (lng >> 2);
lng |= (lng >> 4);
lng |= (lng >> 8);
lng |= (lng >> 16);
lng |= (lng >> 32);
return (lng & ~(lng >>> 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 lng
* the long to examine.
* @return the bit mask indicating the lowest 1 bit in {@code lng}.
* @since Android 1.0
*/
public static long lowestOneBit(long lng) {
return (lng & (-lng));
}
/**
* Determines the number of leading zeros in the specified long value prior
* to the {@link #highestOneBit(long) highest one bit}.
*
* @param lng
* the long to examine.
* @return the number of leading zeros in {@code lng}.
* @since Android 1.0
*/
public static int numberOfLeadingZeros(long lng) {
lng |= lng >> 1;
lng |= lng >> 2;
lng |= lng >> 4;
lng |= lng >> 8;
lng |= lng >> 16;
lng |= lng >> 32;
return bitCount(~lng);
}
/**
* Determines the number of trailing zeros in the specified long value after
* the {@link #lowestOneBit(long) lowest one bit}.
*
* @param lng
* the long to examine.
* @return the number of trailing zeros in {@code lng}.
* @since Android 1.0
*/
public static int numberOfTrailingZeros(long lng) {
return bitCount((lng & -lng) - 1);
}
/**
* Counts the number of 1 bits in the specified long value; this is also
* referred to as population count.
*
* @param lng
* the long to examine.
* @return the number of 1 bits in {@code lng}.
* @since Android 1.0
*/
public static int bitCount(long lng) {
lng = (lng & 0x5555555555555555L) + ((lng >> 1) & 0x5555555555555555L);
lng = (lng & 0x3333333333333333L) + ((lng >> 2) & 0x3333333333333333L);
// adjust for 64-bit integer
int i = (int) ((lng >>> 32) + lng);
i = (i & 0x0F0F0F0F) + ((i >> 4) & 0x0F0F0F0F);
i = (i & 0x00FF00FF) + ((i >> 8) & 0x00FF00FF);
i = (i & 0x0000FFFF) + ((i >> 16) & 0x0000FFFF);
return i;
}
/**
* Rotates the bits of the specified long value to the left by the specified
* number of bits.
*
* @param lng
* the long value to rotate left.
* @param distance
* the number of bits to rotate.
* @return the rotated value.
* @since Android 1.0
*/
public static long rotateLeft(long lng, int distance) {
if (distance == 0) {
return lng;
}
/*
* According to JLS3, 15.19, the right operand of a shift is always
* implicitly masked with 0x3F, which the negation of 'distance' is
* taking advantage of.
*/
return ((lng << distance) | (lng >>> (-distance)));
}
/**
* Rotates the bits of the specified long value to the right by the
* specified number of bits.
*
* @param lng
* the long value to rotate right.
* @param distance
* the number of bits to rotate.
* @return the rotated value.
* @since Android 1.0
*/
public static long rotateRight(long lng, int distance) {
if (distance == 0) {
return lng;
}
/*
* According to JLS3, 15.19, the right operand of a shift is always
* implicitly masked with 0x3F, which the negation of 'distance' is
* taking advantage of.
*/
return ((lng >>> distance) | (lng << (-distance)));
}
/**
* Reverses the order of the bytes of the specified long value.
*
* @param lng
* the long value for which to reverse the byte order.
* @return the reversed value.
* @since Android 1.0
*/
public static long reverseBytes(long lng) {
long b7 = lng >>> 56;
long b6 = (lng >>> 40) & 0xFF00L;
long b5 = (lng >>> 24) & 0xFF0000L;
long b4 = (lng >>> 8) & 0xFF000000L;
long b3 = (lng & 0xFF000000L) << 8;
long b2 = (lng & 0xFF0000L) << 24;
long b1 = (lng & 0xFF00L) << 40;
long b0 = lng << 56;
return (b0 | b1 | b2 | b3 | b4 | b5 | b6 | b7);
}
/**
* Reverses the order of the bits of the specified long value.
*
* @param lng
* the long value for which to reverse the bit order.
* @return the reversed value.
* @since Android 1.0
*/
public static long reverse(long lng) {
// From Hacker's Delight, 7-1, Figure 7-1
lng = (lng & 0x5555555555555555L) << 1 | (lng >> 1)
& 0x5555555555555555L;
lng = (lng & 0x3333333333333333L) << 2 | (lng >> 2)
& 0x3333333333333333L;
lng = (lng & 0x0F0F0F0F0F0F0F0FL) << 4 | (lng >> 4)
& 0x0F0F0F0F0F0F0F0FL;
return reverseBytes(lng);
}
/**
* Returns the value of the {@code signum} function for the specified long
* value.
*
* @param lng
* the long value to check.
* @return -1 if {@code lng} is negative, 1 if {@code lng} is positive, 0 if
* {@code lng} is zero.
* @since Android 1.0
*/
public static int signum(long lng) {
return (lng == 0 ? 0 : (lng < 0 ? -1 : 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.
* </p>
*
* @param lng
* the long value to store in the instance.
* @return a {@code Long} instance containing {@code lng}.
* @since Android 1.0
*/
public static Long valueOf(long lng) {
if (lng < -128 || lng > 127) {
return new Long(lng);
}
return valueOfCache.CACHE[128+(int)lng];
}
static class valueOfCache {
/**
* <p>
* A cache of instances used by {@link Long#valueOf(long)} and auto-boxing.
* </p>
*/
static final Long[] CACHE = new Long[256];
static {
for(int i=-128; i<=127; i++) {
CACHE[i+128] = new Long(i);
}
}
}
}
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