Source Code Cross Referenced for FractionFormat.java in  » Science » Apache-commons-math-1.1 » org » apache » commons » math » fraction » Java Source Code / Java DocumentationJava Source Code and Java Documentation

Java Source Code / Java Documentation
1. 6.0 JDK Core
2. 6.0 JDK Modules
3. 6.0 JDK Modules com.sun
4. 6.0 JDK Modules com.sun.java
5. 6.0 JDK Modules sun
6. 6.0 JDK Platform
7. Ajax
8. Apache Harmony Java SE
9. Aspect oriented
10. Authentication Authorization
11. Blogger System
12. Build
13. Byte Code
14. Cache
15. Chart
16. Chat
17. Code Analyzer
18. Collaboration
19. Content Management System
20. Database Client
21. Database DBMS
22. Database JDBC Connection Pool
23. Database ORM
24. Development
25. EJB Server geronimo
26. EJB Server GlassFish
27. EJB Server JBoss 4.2.1
28. EJB Server resin 3.1.5
29. ERP CRM Financial
30. ESB
31. Forum
32. GIS
33. Graphic Library
34. Groupware
35. HTML Parser
36. IDE
37. IDE Eclipse
38. IDE Netbeans
39. Installer
40. Internationalization Localization
41. Inversion of Control
42. Issue Tracking
43. J2EE
44. JBoss
45. JMS
46. JMX
47. Library
48. Mail Clients
49. Net
50. Parser
51. PDF
52. Portal
53. Profiler
54. Project Management
55. Report
56. RSS RDF
57. Rule Engine
58. Science
59. Scripting
60. Search Engine
61. Security
62. Sevlet Container
63. Source Control
64. Swing Library
65. Template Engine
66. Test Coverage
67. Testing
68. UML
69. Web Crawler
70. Web Framework
71. Web Mail
72. Web Server
73. Web Services
74. Web Services apache cxf 2.0.1
75. Web Services AXIS2
76. Wiki Engine
77. Workflow Engines
78. XML
79. XML UI
Java
Java Tutorial
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Source Code / Java Documentation » Science » Apache commons math 1.1 » org.apache.commons.math.fraction 
Source Cross Referenced  Class Diagram Java Document (Java Doc) 


001:        /*
002:         * Copyright 2005 The Apache Software Foundation.
003:         *
004:         * Licensed under the Apache License, Version 2.0 (the "License");
005:         * you may not use this file except in compliance with the License.
006:         * You may obtain a copy of the License at
007:         *
008:         *      http://www.apache.org/licenses/LICENSE-2.0
009:         *
010:         * Unless required by applicable law or agreed to in writing, software
011:         * distributed under the License is distributed on an "AS IS" BASIS,
012:         * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013:         * See the License for the specific language governing permissions and
014:         * limitations under the License.
015:         */
016:
017:        package org.apache.commons.math.fraction;
018:
019:        import java.io.Serializable;
020:        import java.text.FieldPosition;
021:        import java.text.Format;
022:        import java.text.NumberFormat;
023:        import java.text.ParseException;
024:        import java.text.ParsePosition;
025:        import java.util.Locale;
026:
027:        import org.apache.commons.math.ConvergenceException;
028:
029:        /**
030:         * Formats a Fraction number in proper format or improper format.  The number
031:         * format for each of the whole number, numerator and, denominator can be
032:         * configured.
033:         *
034:         * @since 1.1
035:         * @version $Revision: 348519 $ $Date: 2005-11-23 12:12:18 -0700 (Wed, 23 Nov 2005) $
036:         */
037:        public class FractionFormat extends Format implements  Serializable {
038:
039:            /** Serializable version identifier */
040:            private static final long serialVersionUID = -6337346779577272306L;
041:
042:            /** The format used for the denominator. */
043:            private NumberFormat denominatorFormat;
044:
045:            /** The format used for the numerator. */
046:            private NumberFormat numeratorFormat;
047:
048:            /**
049:             * Create an improper formatting instance with the default number format
050:             * for the numerator and denominator.  
051:             */
052:            public FractionFormat() {
053:                this (getDefaultNumberFormat());
054:            }
055:
056:            /**
057:             * Create an improper formatting instance with a custom number format for
058:             * both the numerator and denominator.
059:             * @param format the custom format for both the numerator and denominator.
060:             */
061:            public FractionFormat(NumberFormat format) {
062:                this (format, (NumberFormat) format.clone());
063:            }
064:
065:            /**
066:             * Create an improper formatting instance with a custom number format for
067:             * the numerator and a custom number format for the denominator.
068:             * @param numeratorFormat the custom format for the numerator.
069:             * @param denominatorFormat the custom format for the denominator.
070:             */
071:            public FractionFormat(NumberFormat numeratorFormat,
072:                    NumberFormat denominatorFormat) {
073:                super ();
074:                this .numeratorFormat = numeratorFormat;
075:                this .denominatorFormat = denominatorFormat;
076:            }
077:
078:            /**
079:             * This static method calls formatFraction() on a default instance of
080:             * FractionFormat.
081:             *
082:             * @param f Fraction object to format
083:             * @return A formatted fraction in proper form.
084:             */
085:            public static String formatFraction(Fraction f) {
086:                return getImproperInstance().format(f);
087:            }
088:
089:            /**
090:             * Get the set of locales for which complex formats are available.  This
091:             * is the same set as the {@link NumberFormat} set. 
092:             * @return available complex format locales.
093:             */
094:            public static Locale[] getAvailableLocales() {
095:                return NumberFormat.getAvailableLocales();
096:            }
097:
098:            /**
099:             * Returns the default complex format for the current locale.
100:             * @return the default complex format.
101:             */
102:            public static FractionFormat getImproperInstance() {
103:                return getImproperInstance(Locale.getDefault());
104:            }
105:
106:            /**
107:             * Returns the default complex format for the given locale.
108:             * @param locale the specific locale used by the format.
109:             * @return the complex format specific to the given locale.
110:             */
111:            public static FractionFormat getImproperInstance(Locale locale) {
112:                NumberFormat f = getDefaultNumberFormat(locale);
113:                return new FractionFormat(f);
114:            }
115:
116:            /**
117:             * Returns the default complex format for the current locale.
118:             * @return the default complex format.
119:             */
120:            public static FractionFormat getProperInstance() {
121:                return getProperInstance(Locale.getDefault());
122:            }
123:
124:            /**
125:             * Returns the default complex format for the given locale.
126:             * @param locale the specific locale used by the format.
127:             * @return the complex format specific to the given locale.
128:             */
129:            public static FractionFormat getProperInstance(Locale locale) {
130:                NumberFormat f = getDefaultNumberFormat(locale);
131:                return new ProperFractionFormat(f);
132:            }
133:
134:            /**
135:             * Create a default number format.  The default number format is based on
136:             * {@link NumberFormat#getNumberInstance(java.util.Locale)} with the only
137:             * customizing is the maximum number of fraction digits, which is set to 0.  
138:             * @return the default number format.
139:             */
140:            protected static NumberFormat getDefaultNumberFormat() {
141:                return getDefaultNumberFormat(Locale.getDefault());
142:            }
143:
144:            /**
145:             * Create a default number format.  The default number format is based on
146:             * {@link NumberFormat#getNumberInstance(java.util.Locale)} with the only
147:             * customizing is the maximum number of fraction digits, which is set to 0.  
148:             * @param locale the specific locale used by the format.
149:             * @return the default number format specific to the given locale.
150:             */
151:            private static NumberFormat getDefaultNumberFormat(Locale locale) {
152:                NumberFormat nf = NumberFormat.getNumberInstance(locale);
153:                nf.setMaximumFractionDigits(0);
154:                nf.setParseIntegerOnly(true);
155:                return nf;
156:            }
157:
158:            /**
159:             * Formats a {@link Fraction} object to produce a string.  The fraction is
160:             * output in improper format.
161:             *
162:             * @param fraction the object to format.
163:             * @param toAppendTo where the text is to be appended
164:             * @param pos On input: an alignment field, if desired. On output: the
165:             *            offsets of the alignment field
166:             * @return the value passed in as toAppendTo.
167:             */
168:            public StringBuffer format(Fraction fraction,
169:                    StringBuffer toAppendTo, FieldPosition pos) {
170:
171:                pos.setBeginIndex(0);
172:                pos.setEndIndex(0);
173:
174:                getNumeratorFormat().format(fraction.getNumerator(),
175:                        toAppendTo, pos);
176:                toAppendTo.append(" / ");
177:                getDenominatorFormat().format(fraction.getDenominator(),
178:                        toAppendTo, pos);
179:
180:                return toAppendTo;
181:            }
182:
183:            /**
184:             * Formats a object to produce a string.  <code>obj</code> must be either a 
185:             * {@link Fraction} object or a {@link Number} object.  Any other type of
186:             * object will result in an {@link IllegalArgumentException} being thrown.
187:             *
188:             * @param obj the object to format.
189:             * @param toAppendTo where the text is to be appended
190:             * @param pos On input: an alignment field, if desired. On output: the
191:             *            offsets of the alignment field
192:             * @return the value passed in as toAppendTo.
193:             * @see java.text.Format#format(java.lang.Object, java.lang.StringBuffer, java.text.FieldPosition)
194:             * @throws IllegalArgumentException is <code>obj</code> is not a valid type.
195:             */
196:            public StringBuffer format(Object obj, StringBuffer toAppendTo,
197:                    FieldPosition pos) {
198:                StringBuffer ret = null;
199:
200:                if (obj instanceof  Fraction) {
201:                    ret = format((Fraction) obj, toAppendTo, pos);
202:                } else if (obj instanceof  Number) {
203:                    try {
204:                        ret = format(
205:                                new Fraction(((Number) obj).doubleValue()),
206:                                toAppendTo, pos);
207:                    } catch (ConvergenceException ex) {
208:                        throw new IllegalArgumentException(
209:                                "Cannot convert given object to a fraction.");
210:                    }
211:                } else {
212:                    throw new IllegalArgumentException(
213:                            "Cannot format given object as a fraction");
214:                }
215:
216:                return ret;
217:            }
218:
219:            /**
220:             * Access the denominator format.
221:             * @return the denominator format.
222:             */
223:            public NumberFormat getDenominatorFormat() {
224:                return denominatorFormat;
225:            }
226:
227:            /**
228:             * Access the numerator format.
229:             * @return the numerator format.
230:             */
231:            public NumberFormat getNumeratorFormat() {
232:                return numeratorFormat;
233:            }
234:
235:            /**
236:             * Parses a string to produce a {@link Fraction} object.
237:             * @param source the string to parse
238:             * @return the parsed {@link Fraction} object.
239:             * @exception ParseException if the beginning of the specified string
240:             *            cannot be parsed.
241:             */
242:            public Fraction parse(String source) throws ParseException {
243:                ParsePosition parsePosition = new ParsePosition(0);
244:                Fraction result = parse(source, parsePosition);
245:                if (parsePosition.getIndex() == 0) {
246:                    throw new ParseException("Unparseable fraction number: \""
247:                            + source + "\"", parsePosition.getErrorIndex());
248:                }
249:                return result;
250:            }
251:
252:            /**
253:             * Parses a string to produce a {@link Fraction} object.  This method
254:             * expects the string to be formatted as an improper fraction.  
255:             * @param source the string to parse
256:             * @param pos input/ouput parsing parameter.
257:             * @return the parsed {@link Fraction} object.
258:             */
259:            public Fraction parse(String source, ParsePosition pos) {
260:                int initialIndex = pos.getIndex();
261:
262:                // parse whitespace
263:                parseAndIgnoreWhitespace(source, pos);
264:
265:                // parse numerator
266:                Number num = getNumeratorFormat().parse(source, pos);
267:                if (num == null) {
268:                    // invalid integer number
269:                    // set index back to initial, error index should already be set
270:                    // character examined.
271:                    pos.setIndex(initialIndex);
272:                    return null;
273:                }
274:
275:                // parse '/'
276:                int startIndex = pos.getIndex();
277:                char c = parseNextCharacter(source, pos);
278:                switch (c) {
279:                case 0:
280:                    // no '/'
281:                    // return num as a fraction
282:                    return new Fraction(num.intValue(), 1);
283:                case '/':
284:                    // found '/', continue parsing denominator
285:                    break;
286:                default:
287:                    // invalid '/'
288:                    // set index back to initial, error index should be the last
289:                    // character examined.
290:                    pos.setIndex(initialIndex);
291:                    pos.setErrorIndex(startIndex);
292:                    return null;
293:                }
294:
295:                // parse whitespace
296:                parseAndIgnoreWhitespace(source, pos);
297:
298:                // parse denominator
299:                Number den = getDenominatorFormat().parse(source, pos);
300:                if (den == null) {
301:                    // invalid integer number
302:                    // set index back to initial, error index should already be set
303:                    // character examined.
304:                    pos.setIndex(initialIndex);
305:                    return null;
306:                }
307:
308:                return new Fraction(num.intValue(), den.intValue());
309:            }
310:
311:            /**
312:             * Parses a string to produce a object.
313:             * @param source the string to parse
314:             * @param pos input/ouput parsing parameter.
315:             * @return the parsed object.
316:             * @see java.text.Format#parseObject(java.lang.String, java.text.ParsePosition)
317:             */
318:            public Object parseObject(String source, ParsePosition pos) {
319:                return parse(source, pos);
320:            }
321:
322:            /**
323:             * Modify the denominator format.
324:             * @param format the new denominator format value.
325:             * @throws IllegalArgumentException if <code>format</code> is
326:             *         <code>null</code>.
327:             */
328:            public void setDenominatorFormat(NumberFormat format) {
329:                if (format == null) {
330:                    throw new IllegalArgumentException(
331:                            "denominator format can not be null.");
332:                }
333:                this .denominatorFormat = format;
334:            }
335:
336:            /**
337:             * Modify the numerator format.
338:             * @param format the new numerator format value.
339:             * @throws IllegalArgumentException if <code>format</code> is
340:             *         <code>null</code>.
341:             */
342:            public void setNumeratorFormat(NumberFormat format) {
343:                if (format == null) {
344:                    throw new IllegalArgumentException(
345:                            "numerator format can not be null.");
346:                }
347:                this .numeratorFormat = format;
348:            }
349:
350:            /**
351:             * Parses <code>source</code> until a non-whitespace character is found.
352:             * @param source the string to parse
353:             * @param pos input/ouput parsing parameter.  On output, <code>pos</code>
354:             *        holds the index of the next non-whitespace character.
355:             */
356:            protected static void parseAndIgnoreWhitespace(String source,
357:                    ParsePosition pos) {
358:                parseNextCharacter(source, pos);
359:                pos.setIndex(pos.getIndex() - 1);
360:            }
361:
362:            /**
363:             * Parses <code>source</code> until a non-whitespace character is found.
364:             * @param source the string to parse
365:             * @param pos input/ouput parsing parameter.
366:             * @return the first non-whitespace character.
367:             */
368:            protected static char parseNextCharacter(String source,
369:                    ParsePosition pos) {
370:                int index = pos.getIndex();
371:                int n = source.length();
372:                char ret = 0;
373:
374:                if (index < n) {
375:                    char c;
376:                    do {
377:                        c = source.charAt(index++);
378:                    } while (Character.isWhitespace(c) && index < n);
379:                    pos.setIndex(index);
380:
381:                    if (index < n) {
382:                        ret = c;
383:                    }
384:                }
385:
386:                return ret;
387:            }
388:        }
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.