001/* Format.java -- Abstract superclass for formatting/parsing strings.
002   Copyright (C) 1998, 1999, 2000, 2001, 2003, 2005  Free Software Foundation, Inc.
003
004This file is part of GNU Classpath.
005
006GNU Classpath is free software; you can redistribute it and/or modify
007it under the terms of the GNU General Public License as published by
008the Free Software Foundation; either version 2, or (at your option)
009any later version.
010
011GNU Classpath is distributed in the hope that it will be useful, but
012WITHOUT ANY WARRANTY; without even the implied warranty of
013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014General Public License for more details.
015
016You should have received a copy of the GNU General Public License
017along with GNU Classpath; see the file COPYING.  If not, write to the
018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01902110-1301 USA.
020
021Linking this library statically or dynamically with other modules is
022making a combined work based on this library.  Thus, the terms and
023conditions of the GNU General Public License cover the whole
024combination.
025
026As a special exception, the copyright holders of this library give you
027permission to link this library with independent modules to produce an
028executable, regardless of the license terms of these independent
029modules, and to copy and distribute the resulting executable under
030terms of your choice, provided that you also meet, for each linked
031independent module, the terms and conditions of the license of that
032module.  An independent module is a module which is not derived from
033or based on this library.  If you modify this library, you may extend
034this exception to your version of the library, but you are not
035obligated to do so.  If you do not wish to do so, delete this
036exception statement from your version. */
037
038
039package java.text;
040
041import gnu.java.text.FormatCharacterIterator;
042
043import java.io.Serializable;
044
045/**
046 * This class is the abstract superclass of classes that format and parse
047 * data to/from <code>Strings</code>.  It is guaranteed that any
048 * <code>String</code> produced by a concrete subclass of <code>Format</code>
049 * will be parseable by that same subclass.
050 * <p>
051 * In addition to implementing the abstract methods in this class, subclasses
052 * should provide static factory methods of the form
053 * <code>getInstance()</code> and <code>getInstance(Locale)</code> if the
054 * subclass loads different formatting/parsing schemes based on locale.
055 * These subclasses should also implement a static method called
056 * <code>getAvailableLocales()</code> which returns an array of
057 * available locales in the current runtime environment.
058 *
059 * @author Aaron M. Renn (arenn@urbanophile.com)
060 * @author Per Bothner (bothner@cygnus.com)
061 */
062public abstract class Format implements Serializable, Cloneable
063{
064  /**
065   * For compatability with Sun's JDK 1.4.2 rev. 5
066   */
067  static final long serialVersionUID = -299282585814624189L;
068
069  public static class Field extends AttributedCharacterIterator.Attribute
070  {
071    static final long serialVersionUID = 276966692217360283L;
072
073    protected Field(String name)
074    {
075      super(name);
076    }
077  }
078
079  /**
080   * This method initializes a new instance of <code>Format</code>.
081   * It performs no actions, but acts as a default constructor for
082   * subclasses.
083   */
084  protected Format ()
085  {
086  }
087
088  /**
089   * This method formats an <code>Object</code> into a <code>String</code>.
090   *
091   * @param obj The <code>Object</code> to format.
092   *
093   * @return The formatted <code>String</code>.
094   *
095   * @exception IllegalArgumentException If the <code>Object</code>
096   * cannot be formatted.
097   */
098  public final String format(Object obj) throws IllegalArgumentException
099  {
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}