michael@0: /**
michael@0:  * Copyright (c) 2012, Ben Fortuna
michael@0:  * All rights reserved.
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  *
michael@0:  *  o Redistributions of source code must retain the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer.
michael@0:  *
michael@0:  *  o Redistributions in binary form must reproduce the above copyright
michael@0:  * notice, this list of conditions and the following disclaimer in the
michael@0:  * documentation and/or other materials provided with the distribution.
michael@0:  *
michael@0:  *  o Neither the name of Ben Fortuna nor the names of any other contributors
michael@0:  * may be used to endorse or promote products derived from this software
michael@0:  * without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
michael@0:  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
michael@0:  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
michael@0:  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
michael@0:  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
michael@0:  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
michael@0:  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
michael@0:  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
michael@0:  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: package net.fortuna.ical4j.model;
michael@0: 
michael@0: import java.text.FieldPosition;
michael@0: import java.text.NumberFormat;
michael@0: import java.text.ParsePosition;
michael@0: import java.text.SimpleDateFormat;
michael@0: import java.util.Date;
michael@0: import java.util.GregorianCalendar;
michael@0: import java.util.TimeZone;
michael@0: 
michael@0: import org.apache.commons.logging.Log;
michael@0: import org.apache.commons.logging.LogFactory;
michael@0: 
michael@0: /**
michael@0:  * $Id$ [06-Apr-2004]
michael@0:  * 
michael@0:  * Creates DateFormat objects optimized for common iCalendar date patterns.
michael@0:  * 
michael@0:  * @author Dave Nault dnault@laszlosystems.com
michael@0:  * @see #getInstance(String)
michael@0:  */
michael@0: public final class CalendarDateFormatFactory {
michael@0:     private static final Log LOG = LogFactory.getLog(CalendarDateFormatFactory.class);
michael@0: 
michael@0:     private static final String DATETIME_PATTERN = "yyyyMMdd'T'HHmmss";
michael@0:     private static final String DATETIME_UTC_PATTERN = "yyyyMMdd'T'HHmmss'Z'";
michael@0:     private static final String DATE_PATTERN = "yyyyMMdd";
michael@0:     private static final String TIME_PATTERN = "HHmmss";
michael@0:     private static final String TIME_UTC_PATTERN = "HHmmss'Z'";
michael@0: 
michael@0:     /**
michael@0:      * Constructor made private to enforce static nature.
michael@0:      */
michael@0:     private CalendarDateFormatFactory() {
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Returns DateFormat objects optimized for common iCalendar date patterns. The DateFormats are *not* thread safe.
michael@0:      * Attempts to get or set the Calendar or NumberFormat of an optimized DateFormat will result in an
michael@0:      * UnsupportedOperation exception being thrown.
michael@0:      * 
michael@0:      * @param pattern
michael@0:      *            a SimpleDateFormat-compatible pattern
michael@0:      * @return an optimized DateFormat instance if possible, otherwise a normal SimpleDateFormat instance
michael@0:      */
michael@0:     public static java.text.DateFormat getInstance(String pattern) {
michael@0:         java.text.DateFormat instance = null;
michael@0:         
michael@0:         // if (true) {
michael@0:         // return new SimpleDateFormat(pattern);
michael@0:         // }
michael@0: 
michael@0:         if (pattern.equals(DATETIME_PATTERN) || pattern.equals(DATETIME_UTC_PATTERN)) {
michael@0:             instance = new DateTimeFormat(pattern);
michael@0:         }
michael@0:         else if (pattern.equals(DATE_PATTERN)) {
michael@0:             instance = new DateFormat(pattern);
michael@0:         }
michael@0:         else if (pattern.equals(TIME_PATTERN) || pattern.equals(TIME_UTC_PATTERN)) {
michael@0:             instance = new TimeFormat(pattern);
michael@0:         }
michael@0:         else {
michael@0:             if (LOG.isDebugEnabled()) {
michael@0:                 LOG.debug("unexpected date format pattern: " + pattern);
michael@0:             }
michael@0: 
michael@0:             instance = new SimpleDateFormat(pattern);
michael@0:         }
michael@0:         return instance;
michael@0:     }
michael@0: 
michael@0:     private abstract static class CalendarDateFormat extends java.text.DateFormat {
michael@0:         /**
michael@0: 		 * 
michael@0: 		 */
michael@0:         private static final long serialVersionUID = -4191402739860280205L;
michael@0: 
michael@0:         private static final java.util.TimeZone DEFAULT_TIME_ZONE = TimeZone.getDefault();
michael@0: 
michael@0:         private final String pattern;
michael@0: 
michael@0:         private boolean lenient = true;
michael@0: 
michael@0:         private java.util.TimeZone timeZone = DEFAULT_TIME_ZONE;
michael@0: 
michael@0:         public CalendarDateFormat(String pattern) {
michael@0:             this.pattern = pattern;
michael@0:         }
michael@0: 
michael@0:         public java.util.TimeZone getTimeZone() {
michael@0:             return this.timeZone;
michael@0:         }
michael@0: 
michael@0:         public void setTimeZone(java.util.TimeZone tz) {
michael@0:             this.timeZone = tz;
michael@0:         }
michael@0: 
michael@0:         public void setLenient(boolean lenient) {
michael@0:             this.lenient = lenient;
michael@0:         }
michael@0: 
michael@0:         public boolean isLenient() {
michael@0:             return lenient;
michael@0:         }
michael@0: 
michael@0:         public java.util.Calendar getCalendar() {
michael@0:             throw new UnsupportedOperationException();
michael@0:         }
michael@0: 
michael@0:         public void setCalendar(java.util.Calendar c) {
michael@0:             throw new UnsupportedOperationException();
michael@0:         }
michael@0: 
michael@0:         public NumberFormat getNumberFormat() {
michael@0:             throw new UnsupportedOperationException();
michael@0:         }
michael@0: 
michael@0:         public void setNumberFormat(NumberFormat n) {
michael@0:             throw new UnsupportedOperationException();
michael@0:         }
michael@0: 
michael@0:         public Object clone() {
michael@0:             // don't call super.clone()
michael@0:             final CalendarDateFormat f = (CalendarDateFormat) CalendarDateFormatFactory.getInstance(pattern);
michael@0:             f.setTimeZone(getTimeZone());
michael@0:             f.setLenient(isLenient());
michael@0:             return f;
michael@0:         }
michael@0: 
michael@0:         public boolean equals(Object o) {
michael@0:             if (this == o) {
michael@0:                 return true;
michael@0:             }
michael@0:             if (o == null || getClass() != o.getClass()) {
michael@0:                 return false;
michael@0:             }
michael@0:             if (!super.equals(o)) {
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             final CalendarDateFormat that = (CalendarDateFormat) o;
michael@0: 
michael@0:             if (lenient != that.lenient) {
michael@0:                 return false;
michael@0:             }
michael@0:             if (!pattern.equals(that.pattern)) {
michael@0:                 return false;
michael@0:             }
michael@0:             if (!timeZone.equals(that.timeZone)) {
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             return true;
michael@0:         }
michael@0: 
michael@0:         public int hashCode() {
michael@0:             int result = super.hashCode();
michael@0:             result = 31 * result + pattern.hashCode();
michael@0:             result = 31 * result + (lenient ? 1 : 0);
michael@0:             result = 31 * result + timeZone.hashCode();
michael@0:             return result;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * A custom date-time formatter.
michael@0:      * Parses and formats these patterns:
michael@0:      * 
michael@0:      * <pre>
michael@0:      * yyyyMMdd'T'HHmmss
michael@0:      * yyyyMMdd'T'HHmmss'Z'
michael@0:      * </pre>
michael@0:      */
michael@0:     private static class DateTimeFormat extends CalendarDateFormat {
michael@0: 
michael@0:         /**
michael@0: 		 * 
michael@0: 		 */
michael@0:         private static final long serialVersionUID = 3005824302269636122L;
michael@0: 
michael@0:         final boolean patternEndsWithZ;
michael@0: 
michael@0:         public DateTimeFormat(String pattern) {
michael@0:             super(pattern);
michael@0:             patternEndsWithZ = pattern.endsWith("'Z'");
michael@0:         }
michael@0: 
michael@0:         public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
michael@0:             final java.util.Calendar cal = new GregorianCalendar(getTimeZone());
michael@0:             cal.setTimeInMillis(date.getTime());
michael@0: 
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.YEAR), 4);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.MONTH) + 1, 2);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.DAY_OF_MONTH), 2);
michael@0:             toAppendTo.append("T");
michael@0: 
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.HOUR_OF_DAY), 2);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.MINUTE), 2);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.SECOND), 2);
michael@0: 
michael@0:             if (patternEndsWithZ) {
michael@0:                 toAppendTo.append("Z");
michael@0:             }
michael@0: 
michael@0:             return toAppendTo;
michael@0:         }
michael@0: 
michael@0:         public Date parse(String source, ParsePosition pos) {
michael@0:             // if lenient ignore superfluous input..
michael@0:             if (patternEndsWithZ) {
michael@0:                 if (source.length() > DATETIME_UTC_PATTERN.length() && !isLenient()) {
michael@0:                     pos.setErrorIndex(DATETIME_UTC_PATTERN.length());
michael@0:                     return null;
michael@0:                 }
michael@0:             } else if (source.length() > DATETIME_PATTERN.length() && !isLenient()) {
michael@0:                 pos.setErrorIndex(DATETIME_PATTERN.length());
michael@0:                 return null;
michael@0:             }
michael@0: 
michael@0:             try {
michael@0:                 if (source.charAt(8) != 'T') {
michael@0:                     pos.setErrorIndex(8);
michael@0:                     return null;
michael@0:                 }
michael@0:                 if (patternEndsWithZ && source.charAt(15) != 'Z') {
michael@0:                     pos.setErrorIndex(15);
michael@0:                     return null;
michael@0:                 }
michael@0: 
michael@0:                 final int year = Integer.parseInt(source.substring(0, 4));
michael@0:                 final int month = Integer.parseInt(source.substring(4, 6)) - 1;
michael@0:                 final int day = Integer.parseInt(source.substring(6, 8));
michael@0:                 final int hour = Integer.parseInt(source.substring(9, 11));
michael@0:                 final int minute = Integer.parseInt(source.substring(11, 13));
michael@0:                 final int second = Integer.parseInt(source.substring(13, 15));
michael@0: 
michael@0:                 final Date d = makeCalendar(isLenient(), getTimeZone(),
michael@0:                         year, month, day, hour, minute, second).getTime();
michael@0:                 pos.setIndex(15);
michael@0:                 return d;
michael@0:             } catch (Exception e) {
michael@0:                 return null;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Custom date formatter.
michael@0:      * Parses and formats this pattern:
michael@0:      * 
michael@0:      * <pre>
michael@0:      * yyyyMMdd
michael@0:      * </pre>
michael@0:      */
michael@0:     private static class DateFormat extends CalendarDateFormat {
michael@0: 
michael@0:         /**
michael@0: 		 * 
michael@0: 		 */
michael@0:         private static final long serialVersionUID = -7626077667268431779L;
michael@0: 
michael@0:         public DateFormat(String pattern) {
michael@0:             super(pattern);
michael@0:         }
michael@0: 
michael@0:         public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
michael@0:             final java.util.Calendar cal = java.util.Calendar.getInstance(getTimeZone());
michael@0:             cal.setTimeInMillis(date.getTime());
michael@0: 
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.YEAR), 4);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.MONTH) + 1, 2);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.DAY_OF_MONTH), 2);
michael@0: 
michael@0:             return toAppendTo;
michael@0:         }
michael@0: 
michael@0:         public Date parse(String source, ParsePosition pos) {
michael@0:             // if lenient ignore superfluous input..
michael@0:             if (source.length() > DATE_PATTERN.length() && !isLenient()) {
michael@0:                 pos.setErrorIndex(DATE_PATTERN.length());
michael@0:                 return null;
michael@0:             }
michael@0: 
michael@0:             try {
michael@0:                 final int year = Integer.parseInt(source.substring(0, 4));
michael@0:                 final int month = Integer.parseInt(source.substring(4, 6)) - 1;
michael@0:                 final int day = Integer.parseInt(source.substring(6, 8));
michael@0: 
michael@0:                 final Date d = makeCalendar(isLenient(), getTimeZone(), year, month, day).getTime();
michael@0:                 pos.setIndex(8);
michael@0:                 return d;
michael@0:             } catch (Exception e) {
michael@0:                 return null;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Custom time formatter.
michael@0:      * Parses and formats these patterns:
michael@0:      * 
michael@0:      * <pre>
michael@0:      * HHmmss
michael@0:      * HHmmss'Z'
michael@0:      * </pre>
michael@0:      */
michael@0:     private static class TimeFormat extends CalendarDateFormat {
michael@0: 
michael@0:         /**
michael@0: 		 * 
michael@0: 		 */
michael@0:         private static final long serialVersionUID = -1367114409994225425L;
michael@0: 
michael@0:         final boolean patternEndsWithZ;
michael@0: 
michael@0:         public TimeFormat(String pattern) {
michael@0:             super(pattern);
michael@0:             patternEndsWithZ = pattern.endsWith("'Z'");
michael@0:         }
michael@0: 
michael@0:         public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) {
michael@0:             final java.util.Calendar cal = new GregorianCalendar(getTimeZone());
michael@0:             cal.setTimeInMillis(date.getTime());
michael@0: 
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.HOUR_OF_DAY), 2);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.MINUTE), 2);
michael@0:             appendPadded(toAppendTo, cal.get(GregorianCalendar.SECOND), 2);
michael@0: 
michael@0:             if (patternEndsWithZ) {
michael@0:                 toAppendTo.append("Z");
michael@0:             }
michael@0: 
michael@0:             return toAppendTo;
michael@0:         }
michael@0: 
michael@0:         public Date parse(String source, ParsePosition pos) {
michael@0:             // if lenient ignore superfluous input..
michael@0:             if (patternEndsWithZ) {
michael@0:                 if (source.length() > TIME_UTC_PATTERN.length() && !isLenient()) {
michael@0:                     pos.setErrorIndex(TIME_UTC_PATTERN.length());
michael@0:                     return null;
michael@0:                 }
michael@0:             } else if (source.length() > TIME_PATTERN.length() && !isLenient()) {
michael@0:                 pos.setErrorIndex(TIME_PATTERN.length());
michael@0:                 return null;
michael@0:             }
michael@0: 
michael@0:             try {
michael@0:                 if (patternEndsWithZ && source.charAt(6) != 'Z') {
michael@0:                     pos.setErrorIndex(6);
michael@0:                     return null;
michael@0:                 }
michael@0: 
michael@0:                 final int hour = Integer.parseInt(source.substring(0, 2));
michael@0:                 final int minute = Integer.parseInt(source.substring(2, 4));
michael@0:                 final int second = Integer.parseInt(source.substring(4, 6));
michael@0: 
michael@0:                 final Date d = makeCalendar(isLenient(), getTimeZone(), 1970, 0, 1, hour, minute, second).getTime();
michael@0:                 pos.setIndex(6);
michael@0:                 return d;
michael@0:             } catch (Exception e) {
michael@0:                 return null;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private static java.util.Calendar makeCalendar(boolean lenient, java.util.TimeZone timeZone, int year,
michael@0:             int zeroBasedMonth, int day, int hour, int minutes, int seconds) {
michael@0:         final java.util.Calendar cal = new GregorianCalendar(timeZone);
michael@0:         cal.setLenient(lenient);
michael@0:         cal.set(year, zeroBasedMonth, day, hour, minutes, seconds);
michael@0:         cal.set(java.util.Calendar.MILLISECOND, 0);
michael@0:         return cal;
michael@0:     }
michael@0: 
michael@0:     private static java.util.Calendar makeCalendar(boolean lenient, TimeZone timeZone, int year, int month, int day) {
michael@0:         return makeCalendar(lenient, timeZone, year, month, day, 0, 0, 0);
michael@0:     }
michael@0: 
michael@0:     private static void appendPadded(StringBuffer toAppendTo, int value, int fieldWidth) {
michael@0:         final String s = Integer.toString(value);
michael@0:         final int max = fieldWidth - s.length();
michael@0:         for (int i = 0; i < max; i++) {
michael@0:             toAppendTo.append("0");
michael@0:         }
michael@0:         toAppendTo.append(s);
michael@0:     }
michael@0: 
michael@0: }