| 1 | /* |
| 2 | * Copyright 2001-2005 Stephen Colebourne |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | package org.joda.time.format; |
| 17 | |
| 18 | import java.io.IOException; |
| 19 | import java.io.Writer; |
| 20 | import java.util.Locale; |
| 21 | |
| 22 | import org.joda.time.MutablePeriod; |
| 23 | import org.joda.time.Period; |
| 24 | import org.joda.time.PeriodType; |
| 25 | import org.joda.time.ReadWritablePeriod; |
| 26 | import org.joda.time.ReadablePeriod; |
| 27 | |
| 28 | /** |
| 29 | * Controls the printing and parsing of a time period to and from a string. |
| 30 | * <p> |
| 31 | * This class is the main API for printing and parsing used by most applications. |
| 32 | * Instances of this class are created via one of three factory classes: |
| 33 | * <ul> |
| 34 | * <li>{@link PeriodFormat} - formats by pattern and style</li> |
| 35 | * <li>{@link ISOPeriodFormat} - ISO8601 formats</li> |
| 36 | * <li>{@link PeriodFormatterBuilder} - complex formats created via method calls</li> |
| 37 | * </ul> |
| 38 | * <p> |
| 39 | * An instance of this class holds a reference internally to one printer and |
| 40 | * one parser. It is possible that one of these may be null, in which case the |
| 41 | * formatter cannot print/parse. This can be checked via the {@link #isPrinter()} |
| 42 | * and {@link #isParser()} methods. |
| 43 | * <p> |
| 44 | * The underlying printer/parser can be altered to behave exactly as required |
| 45 | * by using a decorator modifier: |
| 46 | * <ul> |
| 47 | * <li>{@link #withLocale(Locale)} - returns a new formatter that uses the specified locale</li> |
| 48 | * </ul> |
| 49 | * This returns a new formatter (instances of this class are immutable). |
| 50 | * <p> |
| 51 | * The main methods of the class are the <code>printXxx</code> and |
| 52 | * <code>parseXxx</code> methods. These are used as follows: |
| 53 | * <pre> |
| 54 | * // print using the default locale |
| 55 | * String periodStr = formatter.print(period); |
| 56 | * // print using the French locale |
| 57 | * String periodStr = formatter.withLocale(Locale.FRENCH).print(period); |
| 58 | * |
| 59 | * // parse using the French locale |
| 60 | * Period date = formatter.withLocale(Locale.FRENCH).parsePeriod(str); |
| 61 | * </pre> |
| 62 | * |
| 63 | * @author Brian S O'Neill |
| 64 | * @author Stephen Colebourne |
| 65 | * @since 1.0 |
| 66 | */ |
| 67 | public class PeriodFormatter { |
| 68 | |
| 69 | /** The internal printer used to output the datetime. */ |
| 70 | private final PeriodPrinter iPrinter; |
| 71 | /** The internal parser used to output the datetime. */ |
| 72 | private final PeriodParser iParser; |
| 73 | /** The locale to use for printing and parsing. */ |
| 74 | private final Locale iLocale; |
| 75 | /** The period type used in parsing. */ |
| 76 | private final PeriodType iParseType; |
| 77 | |
| 78 | /** |
| 79 | * Creates a new formatter, however you will normally use the factory |
| 80 | * or the builder. |
| 81 | * |
| 82 | * @param printer the internal printer, null if cannot print |
| 83 | * @param parser the internal parser, null if cannot parse |
| 84 | */ |
| 85 | public PeriodFormatter( |
| 86 | PeriodPrinter printer, PeriodParser parser) { |
| 87 | super(); |
| 88 | iPrinter = printer; |
| 89 | iParser = parser; |
| 90 | iLocale = null; |
| 91 | iParseType = null; |
| 92 | } |
| 93 | |
| 94 | /** |
| 95 | * Constructor. |
| 96 | * |
| 97 | * @param printer the internal printer, null if cannot print |
| 98 | * @param parser the internal parser, null if cannot parse |
| 99 | * @param locale the locale to use |
| 100 | * @param type the parse period type |
| 101 | */ |
| 102 | private PeriodFormatter( |
| 103 | PeriodPrinter printer, PeriodParser parser, |
| 104 | Locale locale, PeriodType type) { |
| 105 | super(); |
| 106 | iPrinter = printer; |
| 107 | iParser = parser; |
| 108 | iLocale = locale; |
| 109 | iParseType = type; |
| 110 | } |
| 111 | |
| 112 | //----------------------------------------------------------------------- |
| 113 | /** |
| 114 | * Is this formatter capable of printing. |
| 115 | * |
| 116 | * @return true if this is a printer |
| 117 | */ |
| 118 | public boolean isPrinter() { |
| 119 | return (iPrinter != null); |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * Gets the internal printer object that performs the real printing work. |
| 124 | * |
| 125 | * @return the internal printer |
| 126 | */ |
| 127 | public PeriodPrinter getPrinter() { |
| 128 | return iPrinter; |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * Is this formatter capable of parsing. |
| 133 | * |
| 134 | * @return true if this is a parser |
| 135 | */ |
| 136 | public boolean isParser() { |
| 137 | return (iParser != null); |
| 138 | } |
| 139 | |
| 140 | /** |
| 141 | * Gets the internal parser object that performs the real parsing work. |
| 142 | * |
| 143 | * @return the internal parser |
| 144 | */ |
| 145 | public PeriodParser getParser() { |
| 146 | return iParser; |
| 147 | } |
| 148 | |
| 149 | //----------------------------------------------------------------------- |
| 150 | /** |
| 151 | * Returns a new formatter with a different locale that will be used |
| 152 | * for printing and parsing. |
| 153 | * <p> |
| 154 | * A PeriodFormatter is immutable, so a new instance is returned, |
| 155 | * and the original is unaltered and still usable. |
| 156 | * |
| 157 | * @param locale the locale to use |
| 158 | * @return the new formatter |
| 159 | */ |
| 160 | public PeriodFormatter withLocale(Locale locale) { |
| 161 | if (locale == getLocale() || (locale != null && locale.equals(getLocale()))) { |
| 162 | return this; |
| 163 | } |
| 164 | return new PeriodFormatter(iPrinter, iParser, locale, iParseType); |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * Gets the locale that will be used for printing and parsing. |
| 169 | * |
| 170 | * @return the locale to use |
| 171 | */ |
| 172 | public Locale getLocale() { |
| 173 | return iLocale; |
| 174 | } |
| 175 | |
| 176 | //----------------------------------------------------------------------- |
| 177 | /** |
| 178 | * Returns a new formatter with a different PeriodType for parsing. |
| 179 | * <p> |
| 180 | * A PeriodFormatter is immutable, so a new instance is returned, |
| 181 | * and the original is unaltered and still usable. |
| 182 | * |
| 183 | * @param type the type to use in parsing |
| 184 | * @return the new formatter |
| 185 | */ |
| 186 | public PeriodFormatter withParseType(PeriodType type) { |
| 187 | if (type == iParseType) { |
| 188 | return this; |
| 189 | } |
| 190 | return new PeriodFormatter(iPrinter, iParser, iLocale, type); |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * Gets the PeriodType that will be used for parsing. |
| 195 | * |
| 196 | * @return the parse type to use |
| 197 | */ |
| 198 | public PeriodType getParseType() { |
| 199 | return iParseType; |
| 200 | } |
| 201 | |
| 202 | //----------------------------------------------------------------------- |
| 203 | /** |
| 204 | * Prints a ReadablePeriod to a StringBuffer. |
| 205 | * |
| 206 | * @param buf the formatted period is appended to this buffer |
| 207 | * @param period the period to format, not null |
| 208 | */ |
| 209 | public void printTo(StringBuffer buf, ReadablePeriod period) { |
| 210 | checkPrinter(); |
| 211 | checkPeriod(period); |
| 212 | |
| 213 | getPrinter().printTo(buf, period, iLocale); |
| 214 | } |
| 215 | |
| 216 | /** |
| 217 | * Prints a ReadablePeriod to a Writer. |
| 218 | * |
| 219 | * @param out the formatted period is written out |
| 220 | * @param period the period to format, not null |
| 221 | */ |
| 222 | public void printTo(Writer out, ReadablePeriod period) throws IOException { |
| 223 | checkPrinter(); |
| 224 | checkPeriod(period); |
| 225 | |
| 226 | getPrinter().printTo(out, period, iLocale); |
| 227 | } |
| 228 | |
| 229 | /** |
| 230 | * Prints a ReadablePeriod to a new String. |
| 231 | * |
| 232 | * @param period the period to format, not null |
| 233 | * @return the printed result |
| 234 | */ |
| 235 | public String print(ReadablePeriod period) { |
| 236 | checkPrinter(); |
| 237 | checkPeriod(period); |
| 238 | |
| 239 | PeriodPrinter printer = getPrinter(); |
| 240 | StringBuffer buf = new StringBuffer(printer.calculatePrintedLength(period, iLocale)); |
| 241 | printer.printTo(buf, period, iLocale); |
| 242 | return buf.toString(); |
| 243 | } |
| 244 | |
| 245 | /** |
| 246 | * Checks whether printing is supported. |
| 247 | * |
| 248 | * @throws UnsupportedOperationException if printing is not supported |
| 249 | */ |
| 250 | private void checkPrinter() { |
| 251 | if (iPrinter == null) { |
| 252 | throw new UnsupportedOperationException("Printing not supported"); |
| 253 | } |
| 254 | } |
| 255 | |
| 256 | /** |
| 257 | * Checks whether the period is non-null. |
| 258 | * |
| 259 | * @throws IllegalArgumentException if the period is null |
| 260 | */ |
| 261 | private void checkPeriod(ReadablePeriod period) { |
| 262 | if (period == null) { |
| 263 | throw new IllegalArgumentException("Period must not be null"); |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | //----------------------------------------------------------------------- |
| 268 | /** |
| 269 | * Parses a period from the given text, at the given position, saving the |
| 270 | * result into the fields of the given ReadWritablePeriod. If the parse |
| 271 | * succeeds, the return value is the new text position. Note that the parse |
| 272 | * may succeed without fully reading the text. |
| 273 | * <p> |
| 274 | * The parse type of the formatter is not used by this method. |
| 275 | * <p> |
| 276 | * If it fails, the return value is negative, but the period may still be |
| 277 | * modified. To determine the position where the parse failed, apply the |
| 278 | * one's complement operator (~) on the return value. |
| 279 | * |
| 280 | * @param period a period that will be modified |
| 281 | * @param text text to parse |
| 282 | * @param position position to start parsing from |
| 283 | * @return new position, if negative, parse failed. Apply complement |
| 284 | * operator (~) to get position of failure |
| 285 | * @throws IllegalArgumentException if any field is out of range |
| 286 | */ |
| 287 | public int parseInto(ReadWritablePeriod period, String text, int position) { |
| 288 | checkParser(); |
| 289 | checkPeriod(period); |
| 290 | |
| 291 | return getParser().parseInto(period, text, position, iLocale); |
| 292 | } |
| 293 | |
| 294 | /** |
| 295 | * Parses a period from the given text, returning a new Period. |
| 296 | * |
| 297 | * @param text text to parse |
| 298 | * @return parsed value in a Period object |
| 299 | * @throws IllegalArgumentException if any field is out of range |
| 300 | */ |
| 301 | public Period parsePeriod(String text) { |
| 302 | checkParser(); |
| 303 | |
| 304 | return parseMutablePeriod(text).toPeriod(); |
| 305 | } |
| 306 | |
| 307 | /** |
| 308 | * Parses a period from the given text, returning a new MutablePeriod. |
| 309 | * |
| 310 | * @param text text to parse |
| 311 | * @return parsed value in a MutablePeriod object |
| 312 | * @throws IllegalArgumentException if any field is out of range |
| 313 | */ |
| 314 | public MutablePeriod parseMutablePeriod(String text) { |
| 315 | checkParser(); |
| 316 | |
| 317 | MutablePeriod period = new MutablePeriod(0, iParseType); |
| 318 | int newPos = getParser().parseInto(period, text, 0, iLocale); |
| 319 | if (newPos >= 0) { |
| 320 | if (newPos >= text.length()) { |
| 321 | return period; |
| 322 | } |
| 323 | } else { |
| 324 | newPos = ~newPos; |
| 325 | } |
| 326 | throw new IllegalArgumentException(FormatUtils.createErrorMessage(text, newPos)); |
| 327 | } |
| 328 | |
| 329 | /** |
| 330 | * Checks whether parsing is supported. |
| 331 | * |
| 332 | * @throws UnsupportedOperationException if parsing is not supported |
| 333 | */ |
| 334 | private void checkParser() { |
| 335 | if (iParser == null) { |
| 336 | throw new UnsupportedOperationException("Parsing not supported"); |
| 337 | } |
| 338 | } |
| 339 | |
| 340 | } |