Source for java.text.Format

   1: /* Format.java -- Abstract superclass for formatting/parsing strings.
   2:    Copyright (C) 1998, 1999, 2000, 2001, 2003, 2005  Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10:  
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.text;
  40: 
  41: import gnu.java.text.FormatCharacterIterator;
  42: 
  43: import java.io.Serializable;
  44: 
  45: /**
  46:  * This class is the abstract superclass of classes that format and parse
  47:  * data to/from <code>Strings</code>.  It is guaranteed that any 
  48:  * <code>String</code> produced by a concrete subclass of <code>Format</code>
  49:  * will be parseable by that same subclass.
  50:  * <p>
  51:  * In addition to implementing the abstract methods in this class, subclasses
  52:  * should provide static factory methods of the form 
  53:  * <code>getInstance()</code> and <code>getInstance(Locale)</code> if the
  54:  * subclass loads different formatting/parsing schemes based on locale.
  55:  * These subclasses should also implement a static method called
  56:  * <code>getAvailableLocales()</code> which returns an array of 
  57:  * available locales in the current runtime environment.
  58:  *
  59:  * @author Aaron M. Renn (arenn@urbanophile.com)
  60:  * @author Per Bothner (bothner@cygnus.com)
  61:  */
  62: public abstract class Format implements Serializable, Cloneable
  63: {
  64:   /**
  65:    * For compatability with Sun's JDK 1.4.2 rev. 5
  66:    */
  67:   static final long serialVersionUID = -299282585814624189L;
  68: 
  69:   public static class Field extends AttributedCharacterIterator.Attribute
  70:   {
  71:     static final long serialVersionUID = 276966692217360283L;
  72:    
  73:     protected Field(String name)
  74:     {
  75:       super(name);
  76:     }
  77:   }
  78:   
  79:   /**
  80:    * This method initializes a new instance of <code>Format</code>.
  81:    * It performs no actions, but acts as a default constructor for
  82:    * subclasses.
  83:    */
  84:   public Format ()
  85:   {
  86:   }
  87: 
  88:   /**
  89:    * This method formats an <code>Object</code> into a <code>String</code>.
  90:    * 
  91:    * @param obj The <code>Object</code> to format.
  92:    *
  93:    * @return The formatted <code>String</code>.
  94:    *
  95:    * @exception IllegalArgumentException If the <code>Object</code>
  96:    * cannot be formatted. 
  97:    */
  98:   public final String format(Object obj) throws IllegalArgumentException
  99:   {
 100:     StringBuffer sb = new StringBuffer ();
 101:     format (obj, sb, new FieldPosition (0));
 102:     return sb.toString ();
 103:   }
 104: 
 105:   /**
 106:    * This method formats an <code>Object</code> into a <code>String</code> and
 107:    * appends the <code>String</code> to a <code>StringBuffer</code>.
 108:    *
 109:    * @param obj The <code>Object</code> to format.
 110:    * @param sb The <code>StringBuffer</code> to append to.
 111:    * @param pos The desired <code>FieldPosition</code>, which is also
 112:    *            updated by this call. 
 113:    *
 114:    * @return The updated <code>StringBuffer</code>.
 115:    *
 116:    * @exception IllegalArgumentException If the <code>Object</code>
 117:    * cannot be formatted. 
 118:    */
 119:   public abstract StringBuffer format (Object obj, StringBuffer sb,
 120:                        FieldPosition pos)
 121:     throws IllegalArgumentException;
 122: 
 123:   /**
 124:    * This method parses a <code>String</code> and converts the parsed 
 125:    * contents into an <code>Object</code>.
 126:    *
 127:    * @param str The <code>String</code> to parse.
 128:    *
 129:    * @return The resulting <code>Object</code>.
 130:    *
 131:    * @exception ParseException If the <code>String</code> cannot be parsed.
 132:    */
 133:   public Object parseObject (String str) throws ParseException
 134:   {
 135:     ParsePosition pos = new ParsePosition(0);
 136:     Object result = parseObject (str, pos);
 137:     if (result == null)
 138:       {
 139:     int index = pos.getErrorIndex();
 140:     if (index < 0)
 141:       index = pos.getIndex();
 142:     throw new ParseException("parseObject failed", index);
 143:       }
 144:     return result;
 145:   }
 146: 
 147:   /**
 148:    * This method parses a <code>String</code> and converts the parsed
 149:    * contents into an <code>Object</code>. 
 150:    *
 151:    * @param str The <code>String</code> to parse.
 152:    * @param pos The starting parse index on input, the ending parse
 153:    *            index on output. 
 154:    *
 155:    * @return The parsed <code>Object</code>, or <code>null</code> in
 156:    *         case of error.
 157:    */
 158:   public abstract Object parseObject (String str, ParsePosition pos);
 159: 
 160:   public AttributedCharacterIterator formatToCharacterIterator(Object obj)
 161:   {
 162:     return new FormatCharacterIterator(format(obj), null, null);
 163:   }
 164: 
 165:   /**
 166:    * Creates a copy of this object.
 167:    *
 168:    * @return The copied <code>Object</code>.
 169:    */
 170:   public Object clone ()
 171:   {
 172:     try
 173:       {
 174:     return super.clone ();
 175:       }
 176:     catch (CloneNotSupportedException e)
 177:       {
 178:     return null;
 179:       }
 180:   }
 181: }