hexnumberformat.java

来自「一个用java写的mail.里面的代码值得我们去研究！学习。」· Java 代码 · 共 130 行

/*
** $Id: HexNumberFormat.java,v 1.3 2001/05/07 12:35:09 kunugi Exp $
**
** Copyright (c) 2000-2001 Jeff Gay
** on behalf of ICEMail.org <http://www.icemail.org>
** Copyright (c) 1997-2000 by Timothy Gerard Endres
** 
** This program is free software.
** 
** You may redistribute it and/or modify it under the terms of the GNU
** General Public License as published by the Free Software Foundation.
** Version 2 of the license should be included with this distribution in
** the file LICENSE, as well as License.html. If the license is not
** included with this distribution, you may find a copy at the FSF web
** site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
**
** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,
** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR
** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY
** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR
** REDISTRIBUTION OF THIS SOFTWARE. 
*/

package org.icemail.text;

import java.text.FieldPosition;
import java.text.Format;
import java.text.ParseException;
import java.text.ParsePosition;


/**
 * The HexNumberFormat class implements the code necessary
 * to format and parse Hexidecimal integer numbers.
 *
 * @see java.text.NumberFormat
 */

public class HexNumberFormat
  extends Format
{                        
  private static char[]  lowChars;
  private static char[]  uprChars;

  private int            count;
  private String         pattern;
  private static char[]  hexChars;

  static {
    HexNumberFormat.lowChars = new char[20];
    HexNumberFormat.uprChars = new char[20];
    
    HexNumberFormat.uprChars[0] = HexNumberFormat.lowChars[0] = '0';
    HexNumberFormat.uprChars[1] = HexNumberFormat.lowChars[1] = '1';
    HexNumberFormat.uprChars[2] = HexNumberFormat.lowChars[2] = '2';
    HexNumberFormat.uprChars[3] = HexNumberFormat.lowChars[3] = '3';
    HexNumberFormat.uprChars[4] = HexNumberFormat.lowChars[4] = '4';
    HexNumberFormat.uprChars[5] = HexNumberFormat.lowChars[5] = '5';
    HexNumberFormat.uprChars[6] = HexNumberFormat.lowChars[6] = '6';
    HexNumberFormat.uprChars[7] = HexNumberFormat.lowChars[7] = '7';
    HexNumberFormat.uprChars[8] = HexNumberFormat.lowChars[8] = '8';
    HexNumberFormat.uprChars[9] = HexNumberFormat.lowChars[9] = '9';
    HexNumberFormat.uprChars[10] = 'A'; HexNumberFormat.lowChars[10] = 'a';
    HexNumberFormat.uprChars[11] = 'B'; HexNumberFormat.lowChars[11] = 'b';
    HexNumberFormat.uprChars[12] = 'C'; HexNumberFormat.lowChars[12] = 'c';
    HexNumberFormat.uprChars[13] = 'D'; HexNumberFormat.lowChars[13] = 'd';
    HexNumberFormat.uprChars[14] = 'E'; HexNumberFormat.lowChars[14] = 'e';
    HexNumberFormat.uprChars[15] = 'F'; HexNumberFormat.lowChars[15] = 'f';
    }

  static public final HexNumberFormat
  getInstance() {
    return new HexNumberFormat( "XXXXXXXX" );
  }

  public
  HexNumberFormat( String pattern ) {
    super();
    this.pattern = pattern;
    this.count = pattern.length();
    this.hexChars = ( pattern.charAt(0) == 'X' ? HexNumberFormat.uprChars :
                                                 HexNumberFormat.lowChars );
  }

  public String
  format( int hexNum ) throws IllegalArgumentException
  {
    FieldPosition pos = new FieldPosition(0);
    StringBuffer hexBuf = new StringBuffer(8);

    format( new Integer( hexNum ), hexBuf, pos );

    return hexBuf.toString();
  }

  public StringBuffer
  format( Object hexInt, StringBuffer appendTo, FieldPosition fieldPos )
    throws IllegalArgumentException {
    char[] hexBuf = new char[16];
    
    int end = fieldPos.getEndIndex();
    int beg = fieldPos.getBeginIndex();

    int hexNum = ((Integer) hexInt).intValue();

    for ( int i = 7 ; i >= 0 ; --i ) {
      hexBuf[i] = this.hexChars[ (hexNum & 0x0F) ];
      hexNum = hexNum >> 4;
    }

    for ( int i = (8 - this.count) ; i < 8 ; ++i ) {
      appendTo.append( hexBuf[i] );
    }

    return appendTo;
  }

  public int
  parse( String source ) throws ParseException {
    throw new ParseException( "unimplemented!", 0 );
  }

  public Object
  parseObject( String source, ParsePosition pos ) {
    return null;
  }

}