001 /* Format.java -- Abstract superclass for formatting/parsing strings.
002 Copyright (C) 1998, 1999, 2000, 2001, 2003, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package java.text;
040
041 import gnu.java.text.FormatCharacterIterator;
042
043 import 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 */
062 public 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 }