Mega Code Archive
This class allows a number to be converted to its unsigned value
<![CDATA[
/*
* Copyright (C) 1999 Jesse E. Peterson
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
*
*/
//package com.jpeterson.util;
import java.text.CharacterIterator;
import java.text.FieldPosition;
import java.text.Format;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.StringCharacterIterator;
/**
* This class allows a number to be converted to it's unsigned value. This works
* for bytes, shorts, and ints, as the value is returned as a long
*
* @author Jesse Peterson <jesse@jpeterson.com>
*
* @version 1.0
*/
public class Unsigned extends Object {
/**
* Return the unsigned value of the number.
*
* @param number
* a byte value
* @return the unsigned value
*/
public static long unsigned(byte number) {
long result = 0;
BinaryFormat format = new BinaryFormat();
String binary = format.format(number);
StringBuffer buffer = new StringBuffer(binary);
buffer.reverse();
int length = buffer.length();
for (int i = 0; i < length; i++) {
result += (buffer.charAt(i) == '1') ? 1 << i : 0;
}
return (result);
}
/**
* Return the unsigned value of the number.
*
* @param number
* a short value
* @return the unsigned value
*/
public static long unsigned(short number) {
long result = 0;
BinaryFormat format = new BinaryFormat();
String binary = format.format(number);
StringBuffer buffer = new StringBuffer(binary);
buffer.reverse();
int length = buffer.length();
for (int i = 0; i < length; i++) {
result += (buffer.charAt(i) == '1') ? 1 << i : 0;
}
return (result);
}
/**
* Return the unsigned value of the number.
*
* @param number
* an int value
* @return the unsigned value
*/
public static long unsigned(int number) {
long result = 0;
BinaryFormat format = new BinaryFormat();
String binary = format.format(number);
StringBuffer buffer = new StringBuffer(binary);
buffer.reverse();
int length = buffer.length();
for (int i = 0; i < length; i++) {
result += (buffer.charAt(i) == '1') ? 1 << i : 0;
}
return (result);
}
// /////////////
// self test //
// /////////////
public static void main(String[] args) {
long expected, result;
byte aByte = (byte) 0xff;
expected = 255;
result = Unsigned.unsigned(aByte);
if (result == expected) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("expected: " + expected + " | result: " + result);
aByte = (byte) 0x80;
expected = 128;
result = Unsigned.unsigned(aByte);
if (result == expected) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("expected: " + expected + " | result: " + result);
short aShort = (short) 0xffff;
expected = 65535;
result = Unsigned.unsigned(aShort);
if (result == expected) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("expected: " + expected + " | result: " + result);
}
}
/**
* This class allows a number to be easily formatted as a binary number. The
* representation uses 1's and 0's.
*
* @author Jesse Peterson <jesse@jpeterson.com>
*
* @version 1.0
*/
class BinaryFormat extends Format {
/**
* spacer between a digit
*/
private String divider;
/**
* Create a new BinaryFormat object with no divider.
*
* @since 1.0
*/
public BinaryFormat() {
divider = "";
}
/**
* Format an object in a binary representation. The object
* <CODE>number</CODE> must be an integer Number; Byte, Short, Integer, or
* Long. If the parameter <CODE>number</CODE> is not one of these, this
* method will throw a <CODE>IllegalArgumentException</CODE>.
*
* @param number
* the number to format
* @param toAppendTo
* where the text is to be appended
* @param pos
* not used
* @return the formatted binary number
*
* @since 1.0
*/
public StringBuffer format(Object number, StringBuffer toAppendTo,
FieldPosition pos) {
if (number instanceof Byte) {
format(((Number) number).byteValue(), toAppendTo, pos);
} else if (number instanceof Short) {
format(((Number) number).shortValue(), toAppendTo, pos);
} else if (number instanceof Integer) {
format(((Number) number).intValue(), toAppendTo, pos);
} else if (number instanceof Long) {
format(((Number) number).longValue(), toAppendTo, pos);
} else {
throw new IllegalArgumentException(
"Cannot format given Object as a Byte, Short, Integer, or Long");
}
return (toAppendTo);
}
/**
* Format a byte, returning an 8 bit binary number.
*
* @param number
* the byte to format
* @return the formatted binary number
*
* @since 1.0
*/
public final String format(byte number) {
return (format(number, new StringBuffer(), new FieldPosition(0))
.toString());
}
/**
* Format a byte, returning an 8 bit binary number.
*
* @param number
* the number to format
* @param toAppendTo
* where the text is to be appended
* @param pos
* not used
* @return the formatted binary number
*
* @since 1.0
*/
public StringBuffer format(byte number, StringBuffer toAppendTo,
FieldPosition pos) {
String prefix = "";
prefix = "";
for (int i = 8; i-- > 0;) {
toAppendTo.append(prefix);
toAppendTo.append(((number & (1 << i)) != 0) ? 1 : 0);
prefix = divider;
}
return (toAppendTo);
}
/**
* Format an array of bytes, returning 8 bits per byte. The byte at index
* zero is the most significant byte, making it possible to enter a stream
* of bytes received from a serial connection very easily.
*
* @param number
* the bytes to format
* @return the formatted binary number
*
* @since 1.0
*/
public final String format(byte[] number) {
return (format(number, new StringBuffer(), new FieldPosition(0))
.toString());
}
/**
* Format an array of bytes, returning 8 bits per bytes. The byte at index
* zero is the most significant byte, making it possible to enter a stream
* of bytes received from a serial connection very easily.
*
* @param number
* the number to format
* @param toAppendTo
* where the text is to be appended
* @param pos
* not used
* @return the formatted binary number
*
* @since 1.0
*/
public StringBuffer format(byte[] number, StringBuffer toAppendTo,
FieldPosition pos) {
String prefix = "";
prefix = "";
for (int i = 0; i < number.length; i++) {
toAppendTo.append(prefix);
format(number[i], toAppendTo, pos);
prefix = divider;
}
return (toAppendTo);
}
/**
* Format a short value, returning a 16 bit binary number.
*
* @param number
* the short to format
* @return the formatted binary number
*
* @since 1.0
*/
public String format(short number) {
return (format(number, new StringBuffer(), new FieldPosition(0))
.toString());
}
/**
* Format a short value, returning a 16 bit binary number.
*
* @param number
* the number to format
* @param toAppendTo
* where the text is to be appended
* @param pos
* not used
* @return the formatted binary number
*
* @since 1.0
*/
public StringBuffer format(short number, StringBuffer toAppendTo,
FieldPosition pos) {
byte[] array = new byte[2];
array[0] = (byte) ((number >>> 8) & 0xff);
array[1] = (byte) (number & 0xff);
return (format(array, toAppendTo, pos));
}
/**
* Format an int value, returning a 32 bit binary number.
*
* @param number
* the int to format
* @return the formatted binary number
*
* @since 1.0
*/
public String format(int number) {
return (format(number, new StringBuffer(), new FieldPosition(0))
.toString());
}
/**
* Format an int value, returning a 32 bit binary number.
*
* @param number
* the number to format
* @param toAppendTo
* where the text is to be appended
* @param pos
* not used
* @return the formatted binary number
*
* @since 1.0
*/
public StringBuffer format(int number, StringBuffer toAppendTo,
FieldPosition pos) {
byte[] array = new byte[4];
array[0] = (byte) ((number >>> 24) & 0xff);
array[1] = (byte) ((number >>> 16) & 0xff);
array[2] = (byte) ((number >>> 8) & 0xff);
array[3] = (byte) (number & 0xff);
return (format(array, toAppendTo, pos));
}
/**
* Format a long value, returning a 64 bit binary number.
*
* @param number
* the long to format
* @return the formatted binary number
*
* @since 1.0
*/
public String format(long number) {
return (format(number, new StringBuffer(), new FieldPosition(0))
.toString());
}
/**
* Format a long value, returning a 64 bit binary number.
*
* @param number
* the number to format
* @param toAppendTo
* where the text is to be appended
* @param pos
* not used
* @return the formatted binary number
*
* @since 1.0
*/
public StringBuffer format(long number, StringBuffer toAppendTo,
FieldPosition pos) {
byte[] array = new byte[8];
array[0] = (byte) ((number >>> 56) & 0xff);
array[1] = (byte) ((number >>> 48) & 0xff);
array[2] = (byte) ((number >>> 40) & 0xff);
array[3] = (byte) ((number >>> 32) & 0xff);
array[4] = (byte) ((number >>> 24) & 0xff);
array[5] = (byte) ((number >>> 16) & 0xff);
array[6] = (byte) ((number >>> 8) & 0xff);
array[7] = (byte) (number & 0xff);
return (format(array, toAppendTo, pos));
}
/**
* Parse a binary number into a Number object. If up to 8 bits are parsed,
* returns a Byte. If more than 8 and up to 16 bits are parsed, return a
* Short. If more than 16 and up to 32 bits are parsed, return an Integer.
* If more than 32 and up to 64 bits are parsed, return a Long.
*
* @param source
* a binary number
* @return return an integer form of Number object if parse is successful
* @exception ParseException
* thrown if source is cannot be converted to a Byte, Short,
* Int, or Long.
*
* @since 1.0
*/
public Number parse(String source) throws ParseException {
int startIndex = 0;
Number result;
ParsePosition parsePosition = new ParsePosition(startIndex);
result = parse(source, parsePosition);
if (result == null) {
throw new ParseException("Unable to parse " + source
+ " using BinaryFormat", parsePosition.getIndex());
}
return (result);
}
/**
* Parse a binary number into a Number object. If up to 8 bits are parsed,
* returns a Byte. If more than 8 and up to 16 bits are parsed, return a
* Short. If more than 16 and up to 32 bits are parsed, return an Integer.
* If more than 32 and up to 64 bits are parsed, return a Long.
*
* @param text
* a binary number
* @param parsePosition
* position to start parsing from
* @return return an integer form of Number object if parse is successful;
* <CODE>null</CODE> otherwise
*
* @since 1.0
*/
public Number parse(String text, ParsePosition parsePosition) {
boolean skipWhitespace = true;
int startIndex, bits;
// remove whitespace
StringCharacterIterator iter = new StringCharacterIterator(text,
parsePosition.getIndex());
for (char c = iter.current(); c != CharacterIterator.DONE; c = iter
.next()) {
if (skipWhitespace && Character.isWhitespace(c)) {
// skip whitespace
continue;
}
}
parsePosition.setIndex(iter.getIndex());
startIndex = parsePosition.getIndex();
Number result = (Number) parseObject(text, parsePosition);
if (result == null) {
return (result);
}
bits = parsePosition.getIndex() - startIndex;
if (bits <= 8) {
result = new Byte(result.byteValue());
} else if (bits <= 16) {
result = new Short(result.shortValue());
} else if (bits <= 32) {
result = new Integer(result.intValue());
} else if (bits <= 64) {
result = new Long(result.longValue());
}
return (result);
}
/**
* Parse a binary number, skipping leading whitespace. Does not throw an
* exception; if no object can be parsed, index is unchanged!
*
* @param source
* the string to parse
* @param status
* the string index to start at
* @return The binary number as a Long object.
*
* @since 1.0
*/
public Object parseObject(String source, ParsePosition status) {
int start = status.getIndex();
boolean success = false;
boolean skipWhitespace = true;
StringBuffer buffer = new StringBuffer();
StringCharacterIterator iter = new StringCharacterIterator(source,
start);
for (char c = iter.current(); c != CharacterIterator.DONE; c = iter
.next()) {
if (skipWhitespace && Character.isWhitespace(c)) {
// skip whitespace
continue;
}
skipWhitespace = false;
if ((c == '1') || (c == '0')) {
success = true;
buffer.append(c);
} else {
break;
}
}
if (!success) {
return (null);
}
// convert binary to long
if (buffer.length() > 64) {
// larger than a long, error
return (null);
}
long result = 0;
buffer.reverse();
int length = buffer.length();
for (int i = 0; i < length; i++) {
result += (buffer.charAt(i) == '1') ? 1 << i : 0;
}
status.setIndex(iter.getIndex());
return (new Long(result));
}
/**
* Set the string used to seperate bits. Is useful some times to insert a
* space between bits for readability.
*
* @param divider
* String to insert between bits
*
* @since 1.0
*/
public void setDivider(String divider) {
this.divider = divider;
}
/**
* Get the string used to seperate bits.
*
* @return the string used to seperate bits
*
* @since 1.0
*/
public String getDivider() {
return (divider);
}
// /////////////
// self test //
// /////////////
public static void main(String[] args) {
String result;
BinaryFormat format = new BinaryFormat();
format.setDivider(" ");
// byte
byte bNumber = 0x33;
result = format.format(bNumber);
if (result.equals("0 0 1 1 0 0 1 1")) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("Byte: " + bNumber + " (" + result + ")");
// byte
bNumber = (byte) 0x85;
result = format.format(bNumber);
if (result.equals("1 0 0 0 0 1 0 1")) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("Byte: " + bNumber + " (" + result + ")");
// short
short sNumber = (short) 0xa2b6;
result = format.format(sNumber);
if (result.equals("1 0 1 0 0 0 1 0 1 0 1 1 0 1 1 0")) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("Byte: " + sNumber + " (" + result + ")");
// int
format.setDivider("");
int iNumber = (int) 0x4321fedc;
result = format.format(iNumber);
if (result.equals("01000011001000011111111011011100")) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("Byte: " + iNumber + " (" + result + ")");
// long
format.setDivider("");
long lNumber = (long) 0x4321fedc4321fedcL;
result = format.format(lNumber);
if (result
.equals("0100001100100001111111101101110001000011001000011111111011011100")) {
System.out.print("Success => ");
} else {
System.out.print("FAILURE => ");
}
System.out.println("Byte: " + lNumber + " (" + result + ")");
}
}
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