HexFormat.java Source code

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/*
 * 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 easily formatted as a hexadecimal number.
 * The representation uses 0-f.
 * 
 * @author Jesse Peterson <jesse@jpeterson.com>
 * 
 * @version 1.0
 */
public class HexFormat extends Format {
    /**
     * should upper case letters be used
     */
    private boolean upperCase;

    private String hexDigits = "0123456789abcdefABCDEF";

    /**
     * Create a new HexFormat object. By default the lower case letters 'a'-'f'
     * are used.
     * 
     * @since 1.0
     */
    public HexFormat() {
        upperCase = false;
    }

    /**
     * Format an object in a hexadecimal 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 hex 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 hex number. (2 digits, with leading
     * zeros)
     * 
     * @param number
     *            the byte to format
     * @return the formatted hex 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 hex number. (2 digits, with leading
     * zeros)
     * 
     * @param number
     *            the number to format
     * @param toAppendTo
     *            where the text is to be appended
     * @param pos
     *            not used
     * @return the formatted binary number
     */
    public StringBuffer format(byte number, StringBuffer toAppendTo, FieldPosition pos) {
        int hiNibble, loNibble;
        String hiDigit, loDigit;

        hiNibble = (number >>> 4) & 0x0f;
        loNibble = number & 0x0f;
        hiDigit = Integer.toHexString(hiNibble);
        loDigit = Integer.toHexString(loNibble);
        if (upperCase) {
            hiDigit = hiDigit.toUpperCase();
            loDigit = loDigit.toUpperCase();
        } else {
            hiDigit = hiDigit.toLowerCase();
            loDigit = loDigit.toLowerCase();
        }
        toAppendTo.append(hiDigit).append(loDigit);

        return (toAppendTo);
    }

    /**
     * Format an array of bytes, returning 8 bits per byte. (2 digits with
     * leading zeros, 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. (2 digits with
     * leading zeros, 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 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) {
        for (int i = 0; i < number.length; i++) {
            format(number[i], toAppendTo, pos);
        }

        return (toAppendTo);
    }

    /**
     * Format a short value, returning a 16 bit hexadecimal number. (4 digits
     * with leading zeros)
     * 
     * @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 hexadecimal number. (4 digits
     * with leading zeros)
     * 
     * @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 hexadecimal number. (8 digits
     * with leading zeros)
     * 
     * @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 hexadecimal number. (8 digits
     * with leading zeros)
     * 
     * @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 hexadecimal number. (16 digits
     * with leading zeros)
     * 
     * @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 hexadecimal number. (16 digits
     * with leading zeros)
     * 
     * @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 hex number into a Number object. Hexadecimal numbers may be
     * indicated with a leading character designation of '0x'. If up to 1 byte
     * is parsed, returns a Byte. If more than 1 and up to 2 bytes are parsed,
     * return a Short. If more than 2 and up to 4 bytes are parsed, return an
     * Integer. If more than 4 and up to 8 bytes 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 HexFormat", parsePosition.getIndex());
        }

        return (result);
    }

    /**
     * Parse a hex number into a Number object. Hexadecimal numbers may be
     * indicated with a leading character designation of '0x'. If up to 1 byte
     * is parsed, returns a Byte. If more than 1 and up to 2 bytes are parsed,
     * return a Short. If more than 2 and up to 4 bytes are parsed, return an
     * Integer. If more than 4 and up to 8 bytes are parsed, return a Long.
     * 
     * @param text
     *            a hexadecimal 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, nibbles;

        // 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;
            }
            break;
        }

        // skip a leading hex designation of the characters '0x'
        if (text.regionMatches(iter.getIndex(), "0x", 0, 2)) {
            parsePosition.setIndex(iter.getIndex() + 2);
        } else {
            parsePosition.setIndex(iter.getIndex());
        }

        startIndex = parsePosition.getIndex();
        Number result = (Number) parseObject(text, parsePosition);

        if (result == null) {
            return (result);
        }

        nibbles = parsePosition.getIndex() - startIndex;
        if (nibbles <= 2) {
            result = new Byte(result.byteValue());
        } else if (nibbles <= 4) {
            result = new Short(result.shortValue());
        } else if (nibbles <= 8) {
            result = new Integer(result.intValue());
        } else if (nibbles <= 16) {
            result = new Long(result.longValue());
        }
        return (result);
    }

    /**
     * Parse a hexadecimal number, skipping leading whitespace. Does not throw
     * an exception; if no object can be parsed, index is unchanged! Hexadecimal
     * numbers may be indicated with a leading character designation of '0x'.
     * 
     * @param source
     *            the string to parse
     * @param status
     *            the string index to start at
     * @return The hexadecimal number as a Long object.
     * 
     * @since 1.0
     */
    public Object parseObject(String source, ParsePosition status) {
        int start = status.getIndex();
        boolean success = false;
        StringBuffer buffer = new StringBuffer();
        char c, c2;
        long result;

        StringCharacterIterator iter = new StringCharacterIterator(source, start);

        for (c = iter.current(); c != CharacterIterator.DONE; c = iter.next()) {
            if (Character.isWhitespace(c)) {
                // skip whitespace
                continue;
            }
            break;
        }

        if (c == CharacterIterator.DONE) {
            return (null);
        }

        if (c == '0') {
            c2 = iter.next();

            if (c2 == CharacterIterator.DONE) {
                return (null);
            }

            if (c2 == 'x') {
                // has a leading '0x' designation, so skip over it
            } else {
                // replace the two characters
                iter.previous();
                iter.previous();
            }
        } else {
            // skip back one character
            iter.previous();
        }

        // gather valid hex digits
        for (c = iter.next(); c != CharacterIterator.DONE; c = iter.next()) {
            if (hexDigits.indexOf(c) != -1) {
                success = true;
                buffer.append(c);
            } else {
                break;
            }
        }

        if (!success) {
            // no valid hex digits
            return (null);
        }

        // convert hex to long
        if (buffer.length() > 16) {
            // larger than a long, error
            // with a buffer full of nibbles, the maximum nibbles in a
            // 64 bit number is 16 nibbles
            return (null);
        }

        // parse number
        try {
            result = Long.parseLong(buffer.toString(), 16);
        } catch (NumberFormatException e) {
            // unable to parse number
            return (null);
        }

        status.setIndex(iter.getIndex());
        return (new Long(result));
    }

    /**
     * Set upper case mode for alpha characters.
     * 
     * @param upperCase
     *            true if upper case alpha characters should be used; false
     *            otherwise
     * 
     * @since 1.0
     */
    public void setUpperCase(boolean upperCase) {
        this.upperCase = upperCase;
    }

    /**
     * Get upper case mode for alpha characters.
     * 
     * @return true if upper case alpha characters should be used; false
     *         otherwise
     * 
     * @since 1.0
     */
    public boolean getUpperCase() {
        return (upperCase);
    }

    /**
     * Is upper case mode for alpha characters in affect?
     * 
     * @return true if upper case alpha characters should be used; false
     *         otherwise
     * 
     * @since 1.0
     */
    public boolean isUpperCase() {
        return (getUpperCase());
    }

    /**
     * Is lower case mode for alpha characters in affect?
     * 
     * @return true if lower case alpha characters should be used; false
     *         otherwise
     * 
     * @since 1.0
     */
    public boolean isLowerCase() {
        return (!getUpperCase());
    }

    // /////////////
    // self test //
    // /////////////
    public static void main(String[] args) {
        String result;
        HexFormat format = new HexFormat();

        // byte
        byte bNumber = 0x33;
        result = format.format(bNumber);
        if (result.equals("33")) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bNumber + " (0x" + result + ")");

        bNumber = (byte) 0x85;
        result = format.format(bNumber);
        if (result.equals("85")) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bNumber + " (0x" + result + ")");

        bNumber = (byte) 0x0f;
        result = format.format(bNumber);
        if (result.equals("0f")) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bNumber + " (0x" + result + ")");

        short sNumber = (short) 0xa2b6;
        result = format.format(sNumber);
        if (result.equals("a2b6")) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bNumber + " (0x" + result + ")");

        format.setUpperCase(true);

        int iNumber = (int) 0x4321fedc;
        result = format.format(iNumber);
        if (result.equals("4321FEDC")) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bNumber + " (0x" + result + ")");

        long lNumber = (long) 0x4321fedc4321fedcL;
        result = format.format(lNumber);
        if (result.equals("4321FEDC4321FEDC")) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bNumber + " (0x" + result + ")");

        String num = "0xfe";
        Number number = null;
        Byte bExpect = new Byte((byte) 0xfe);
        try {
            number = format.parse(num);
        } catch (ParseException e) {
            System.out.println(e);
            e.printStackTrace();
        }
        if ((number instanceof Byte) && (number.equals(bExpect))) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bExpect + " result: " + number);

        num = "0xf";
        number = null;
        bExpect = new Byte((byte) 0xf);
        try {
            number = format.parse(num);
        } catch (ParseException e) {
            System.out.println(e);
            e.printStackTrace();
        }
        if ((number instanceof Byte) && (number.equals(bExpect))) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Byte: " + bExpect + " result: " + number);

        num = "0xf0f0";
        number = null;
        Short sExpect = new Short((short) 0xf0f0);
        try {
            number = format.parse(num);
        } catch (ParseException e) {
            System.out.println(e);
            e.printStackTrace();
        }
        if ((number instanceof Short) && (number.equals(sExpect))) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Short: " + sExpect + " result: " + number);

        num = "0xdEAdbEEf";
        number = null;
        Integer iExpect = new Integer((int) 0xdEAdbEEf);
        try {
            number = format.parse(num);
        } catch (ParseException e) {
            System.out.println(e);
            e.printStackTrace();
        }
        if ((number instanceof Integer) && (number.equals(iExpect))) {
            System.out.print("Success => ");
        } else {
            System.out.print("FAILURE => ");
        }
        System.out.println("Integer: " + iExpect + " result: " + number);
    }
}