/*
* Copyright © 2003 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*/
package java.lang;
/**
* The Integer class wraps a value of the primitive type <code>int</code>
* in an object. An object of type <code>Integer</code> contains a
* single field whose type is <code>int</code>.
* <p>
* In addition, this class provides several methods for converting
* an <code>int</code> to a <code>String</code> and a
* <code>String</code> to an <code>int</code>, as well as other
* constants and methods useful when dealing with an
* <code>int</code>.
*
* @author Lee Boynton
* @author Arthur van Hoff
* @version 12/17/01 (CLDC 1.1)
* @since JDK1.0, CLDC 1.0
*/
public final class Integer {
/**
* The smallest value of type <code>int</code>. The constant
* value of this field is <tt>-2147483648</tt>.
*/
public static final int MIN_VALUE = 0x80000000;
/**
* The largest value of type <code>int</code>. The constant
* value of this field is <tt>2147483647</tt>.
*/
public static final int MAX_VALUE = 0x7fffffff;
/**
* All possible chars for representing a number as a String
*/
final static char[] digits = {
'0' , '1' , '2' , '3' , '4' , '5' ,
'6' , '7' , '8' , '9' , 'a' , 'b' ,
'c' , 'd' , 'e' , 'f' , 'g' , 'h' ,
'i' , 'j' , 'k' , 'l' , 'm' , 'n' ,
'o' , 'p' , 'q' , 'r' , 's' , 't' ,
'u' , 'v' , 'w' , 'x' , 'y' , 'z'
};
/**
* Creates a string representation of the first argument in the
* radix specified by the second argument.
* <p>
* If the radix is smaller than <code>Character.MIN_RADIX</code> or
* larger than <code>Character.MAX_RADIX</code>, then the radix
* <code>10</code> is used instead.
* <p>
* If the first argument is negative, the first element of the
* result is the ASCII minus character <code>'-'</code>
* (<tt>'\u002d'</tt>). If the first
* argument is not negative, no sign character appears in the result.
* <p>
* The remaining characters of the result represent the magnitude of
* the first argument. If the magnitude is zero, it is represented by
* a single zero character <tt>'0'</tt> (<tt>'\u0030'</tt>); otherwise,
* the first character of the representation of the magnitude will
* not be the zero character.
* The following ASCII characters are used as digits:
* <blockquote><pre>
* 0123456789abcdefghijklmnopqrstuvwxyz
* </pre></blockquote>
* These are <tt>'\u0030'</tt> through <tt>'\u0039'</tt> and
* <tt>'\u0061'</tt> through <tt>'\u007a'</tt>. If the
* <tt>radix</tt> is <var>N</var>, then the first <var>N</var> of these
* characters are used as radix-<var>N</var> digits in the order shown.
* Thus, the digits for hexadecimal (radix 16) are
* <blockquote><pre>
* <tt>0123456789abcdef</tt>.
* </pre></blockquote>
*
* @param i an integer.
* @param radix the radix.
* @return a string representation of the argument in the specified radix.
* @see java.lang.Character#MAX_RADIX
* @see java.lang.Character#MIN_RADIX
*/
public static String toString(int i, int radix) {
if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
radix = 10;
char buf[] = new char[33];
boolean negative = (i < 0);
int charPos = 32;
if (!negative) {
i = -i;
}
while (i <= -radix) {
buf[charPos--] = digits[-(i % radix)];
i = i / radix;
}
buf[charPos] = digits[-i];
if (negative) {
buf[--charPos] = '-';
}
return new String(buf, charPos, (33 - charPos));
}
/**
* Creates a string representation of the integer argument as an
* unsigned integer in base 16.
* <p>
* The unsigned integer value is the argument plus 2<sup>32</sup> if
* the argument is negative; otherwise, it is equal to the argument.
* This value is converted to a string of ASCII digits in hexadecimal
* (base 16) with no extra leading <code>0</code>s. If the
* unsigned magnitude is zero, it is represented by a single zero
* character <tt>'0'</tt> (<tt>'\u0030'</tt>); otherwise, the first
* character of the representation of the unsigned magnitude will
* not be the zero character. The following characters are used as
* hexadecimal digits:
* <blockquote><pre>
* 0123456789abcdef
* </pre></blockquote>
* These are the characters <tt>'\u0030'</tt> through <tt>'\u0039'</tt>
* and <tt>'u\0039'</tt> through <tt>'\u0066'</tt>.
*
* @param i an integer.
* @return the string representation of the unsigned integer value
* represented by the argument in hexadecimal (base 16).
* @since JDK1.0.2
*/
public static String toHexString(int i) {
return toUnsignedString(i, 4);
}
/**
* Creates a string representation of the integer argument as an
* unsigned integer in base 8.
* <p>
* The unsigned integer value is the argument plus 2<sup>32</sup> if
* the argument is negative; otherwise, it is equal to the argument.
* This value is converted to a string of ASCII digits in octal
* (base 8) with no extra leading <code>0</code>s.
* <p>
* If the unsigned magnitude is zero, it is represented by a single
* zero character <tt>'0'</tt> (<tt>'\u0030'</tt>); otherwise, the
* first character of the representation of the unsigned magnitude will
* not be the zero character. The octal digits are:
* <blockquote><pre>
* 01234567
* </pre></blockquote>
* These are the characters <tt>'\u0030'</tt> through <tt>'\u0037'</tt>.
*
* @param i an integer
* @return the string representation of the unsigned integer value
* represented by the argument in octal (base 8).
* @since JDK1.0.2
*/
public static String toOctalString(int i) {
return toUnsignedString(i, 3);
}
/**
* Creates a string representation of the integer argument as an
* unsigned integer in base 2.
* <p>
* The unsigned integer value is the argument plus 2<sup>32</sup>if
* the argument is negative; otherwise it is equal to the argument.
* This value is converted to a string of ASCII digits in binary
* (base 2) with no extra leading <code>0</code>s.
*
* If the unsigned magnitude is zero, it is represented by a single
* zero character <tt>'0'</tt> (<tt>'\u0030'</tt>); otherwise, the
* first character of the representation of the unsigned magnitude
* will not be the zero character. The characters <tt>'0'</tt>
* (<tt>'\u0030'</tt>) and <tt>'1'</tt> (<tt>'\u0031'</tt>) are used
* as binary digits.
*
* @param i an integer.
* @return the string representation of the unsigned integer value
* represented by the argument in binary (base 2).
* @since JDK1.0.2
*/
public static String toBinaryString(int i) {
return toUnsignedString(i, 1);
}
/**
* Convert the integer to an unsigned number.
*/
private static String toUnsignedString(int i, int shift) {
char[] buf = new char[32];
int charPos = 32;
int radix = 1 << shift;
int mask = radix - 1;
do {
buf[--charPos] = digits[i & mask];
i >>>= shift;
} while (i != 0);
return new String(buf, charPos, (32 - charPos));
}
/**
* Returns a new String object representing the specified integer. The
* argument is converted to signed decimal representation and returned
* as a string, exactly as if the argument and radix <tt>10</tt> were
* given as arguments to the {@link #toString(int, int)} method.
*
* @param i an integer to be converted.
* @return a string representation of the argument in base 10.
*/
public static String toString(int i) {
return toString(i, 10);
}
/**
* Parses the string argument as a signed integer in the radix
* specified by the second argument. The characters in the string
* must all be digits of the specified radix (as determined by
* whether {@link java.lang.Character#digit(char, int)} returns a
* nonnegative value), except that the first character may be an
* ASCII minus sign <code>'-'</code> (<code>'\u002d'</code>) to
* indicate a negative value. The resulting integer value is returned.
* <p>
* An exception of type <tt>NumberFormatException</tt> is thrown if any
* of the following situations occurs:
* <ul>
* <li>The first argument is <tt>null</tt> or is a string of length zero.
* <li>The radix is either smaller than
* {@link java.lang.Character#MIN_RADIX} or
* larger than {@link java.lang.Character#MAX_RADIX}.
* <li>Any character of the string is not a digit of the specified radix,
* except that the first character may be a minus sign <tt>'-'</tt>
* (<tt>'\u002d'</tt>) provided that the string is longer than length 1.
* <li>The integer value represented by the string is not a value of type
* <tt>int</tt>.
* </ul><p>
* Examples:
* <blockquote><pre>
* parseInt("0", 10) returns 0
* parseInt("473", 10) returns 473
* parseInt("-0", 10) returns 0
* parseInt("-FF", 16) returns -255
* parseInt("1100110", 2) returns 102
* parseInt("2147483647", 10) returns 2147483647
* parseInt("-2147483648", 10) returns -2147483648
* parseInt("2147483648", 10) throws a NumberFormatException
* parseInt("99", 8) throws a NumberFormatException
* parseInt("Kona", 10) throws a NumberFormatException
* parseInt("Kona", 27) returns 411787
* </pre></blockquote>
*
* @param s the <code>String</code> containing the integer.
* @param radix the radix to be used.
* @return the integer represented by the string argument in the
* specified radix.
* @exception NumberFormatException if the string does not contain a
* parsable integer.
*/
public static int parseInt(String s, int radix)
throws NumberFormatException
{
if (s == null) {
throw new NumberFormatException("null");
}
if (radix < Character.MIN_RADIX) {
throw new NumberFormatException("radix " + radix +
" less than Character.MIN_RADIX");
}
if (radix > Character.MAX_RADIX) {
throw new NumberFormatException("radix " + radix +
" greater than Character.MAX_RADIX");
}
int result = 0;
boolean negative = false;
int i = 0, max = s.length();
int limit;
int multmin;
int digit;
if (max > 0) {
if (s.charAt(0) == '-') {
negative = true;
limit = Integer.MIN_VALUE;
i++;
} else {
limit = -Integer.MAX_VALUE;
}
multmin = limit / radix;
if (i < max) {
digit = Character.digit(s.charAt(i++),radix);
if (digit < 0) {
throw new NumberFormatException(s);
} else {
result = -digit;
}
}
while (i < max) {
// Accumulating negatively avoids surprises near MAX_VALUE
digit = Character.digit(s.charAt(i++),radix);
if (digit < 0) {
throw new NumberFormatException(s);
}
if (result < multmin) {
throw new NumberFormatException(s);
}
result *= radix;
if (result < limit + digit) {
throw new NumberFormatException(s);
}
result -= digit;
}
} else {
throw new NumberFormatException(s);
}
if (negative) {
if (i > 1) {
return result;
} else { /* Only got "-" */
throw new NumberFormatException(s);
}
} else {
return -result;
}
}
/**
* Parses the string argument as a signed decimal integer. The
* characters in the string must all be decimal digits, except that
* the first character may be an ASCII minus sign <code>'-'</code>
* (<tt>'\u002d'</tt>) to indicate a negative value. The resulting
* integer value is returned, exactly as if the argument and the radix
* 10 were given as arguments to the
* {@link #parseInt(java.lang.String, int)} method.
*
* @param s a string.
* @return the integer represented by the argument in decimal.
* @exception NumberFormatException if the string does not contain a
* parsable integer.
*/
public static int parseInt(String s) throws NumberFormatException {
return parseInt(s,10);
}
/**
* Returns a new Integer object initialized to the value of the
* specified String. The first argument is interpreted as representing
* a signed integer in the radix specified by the second argument,
* exactly as if the arguments were given to the
* {@link #parseInt(java.lang.String, int)} method. The result is an
* <code>Integer</code> object that represents the integer value
* specified by the string.
* <p>
* In other words, this method returns an <code>Integer</code> object
* equal to the value of:
* <blockquote><pre>
* new Integer(Integer.parseInt(s, radix))
* </pre></blockquote>
*
* @param s the string to be parsed.
* @param radix the radix of the integer represented by string
* <tt>s</tt>
* @return a newly constructed <code>Integer</code> initialized to the
* value represented by the string argument in the specified
* radix.
* @exception NumberFormatException if the String cannot be
* parsed as an <code>int</code>.
*/
public static Integer valueOf(String s, int radix) throws NumberFormatException {
return new Integer(parseInt(s,radix));
}
/**
* Returns a new Integer object initialized to the value of the
* specified String. The argument is interpreted as representing a
* signed decimal integer, exactly as if the argument were given to
* the {@link #parseInt(java.lang.String)} method. The result is an
* <tt>Integer</tt> object that represents the integer value specified
* by the string.
* <p>
* In other words, this method returns an <tt>Integer</tt> object equal
* to the value of:
* <blockquote><pre>
* new Integer(Integer.parseInt(s))
* </pre></blockquote>
*
* @param s the string to be parsed.
* @return a newly constructed <code>Integer</code> initialized to the
* value represented by the string argument.
* @exception NumberFormatException if the string cannot be parsed
* as an integer.
*/
public static Integer valueOf(String s) throws NumberFormatException
{
return new Integer(parseInt(s, 10));
}
/**
* The value of the Integer.
*
* @serial
*/
private int value;
/**
* Constructs a newly allocated <code>Integer</code> object that
* represents the primitive <code>int</code> argument.
*
* @param value the value to be represented by the <code>Integer</code>.
*/
public Integer(int value) {
this.value = value;
}
/**
* Returns the value of this Integer as a byte.
*
* @return the value of this Integer as a byte.
*
* @since JDK1.1
*/
public byte byteValue() {
return (byte)value;
}
/**
* Returns the value of this Integer as a short.
*
* @return the value of this Integer as a short.
*
* @since JDK1.1
*/
public short shortValue() {
return (short)value;
}
/**
* Returns the value of this Integer as an int.
*
* @return the <code>int</code> value represented by this object.
*/
public int intValue() {
return value;
}
/**
* Returns the value of this Integer as a <tt>long</tt>.
*
* @return the <code>int</code> value represented by this object that is
* converted to type <code>long</code> and the result of the
* conversion is returned.
*/
public long longValue() {
return (long)value;
}
/**
* Returns the value of this Integer as a <tt>float</tt>.
*
* @return the <code>int</code> value represented by this object is
* converted to type <code>float</code> and the result of the
* conversion is returned.
* @since CLDC 1.1
*/
public float floatValue() {
return (float)value;
}
/**
* Returns the value of this Integer as a <tt>double</tt>.
*
* @return the <code>int</code> value represented by this object is
* converted to type <code>double</code> and the result of the
* conversion is returned.
* @since CLDC 1.1
*/
public double doubleValue() {
return (double)value;
}
/**
* Returns a String object representing this Integer's value. The
* value is converted to signed decimal representation and returned
* as a string, exactly as if the integer value were given as an
* argument to the {@link java.lang.Integer#toString(int)} method.
*
* @return a string representation of the value of this object in
* base 10.
*/
public String toString() {
return String.valueOf(value);
}
/**
* Returns a hashcode for this Integer.
*
* @return a hash code value for this object, equal to the
* primitive <tt>int</tt> value represented by this
* <tt>Integer</tt> object.
*/
public int hashCode() {
return value;
}
/**
* Compares this object to the specified object.
* The result is <code>true</code> if and only if the argument is not
* <code>null</code> and is an <code>Integer</code> object that contains
* the same <code>int</code> value as this object.
*
* @param obj the object to compare with.
* @return <code>true</code> if the objects are the same;
* <code>false</code> otherwise.
*/
public boolean equals(Object obj) {
if (obj instanceof Integer) {
return value == ((Integer)obj).intValue();
}
return false;
}
}
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