Java tutorial
/******************************************************************************* * Copyright 2013 Open mHealth * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. ******************************************************************************/ /* * Copyright 2012 John Jenkins * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package io.smalldata.ohmageomh.surveys.domain; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.DeserializationContext; import com.fasterxml.jackson.databind.JsonDeserializer; import org.joda.time.DateTime; import org.joda.time.DateTimeZone; import org.joda.time.format.*; import org.springframework.stereotype.Component; import java.io.IOException; /** * <p> * Factory that creates instances of DateTimeFormatter for the W3C's profile of * the ISO 8601 standard. * </p> * * <p> * ISO8601 is the international standard for data interchange and defines many * formats for representing date and time information. W3C has created a * shorter, more specific list of formats. * </p> * * <p> * One major difference between this and the ISODateTimeFormatter is that this * will always parse non-zone'd values, e.g. year, year-month, and * year-month-day, with a default zone of UTC as opposed to the * ISODateTimeFormatter which will give them JodaTime's configured default time * zone. * </p> * * @author John Jenkins */ @Component public class ISOW3CDateTimeFormat { /** * <p> * A de-serializer for de-serializing text into a DateTime object. * </p> * * @author John Jenkins */ public static class Deserializer extends JsonDeserializer<DateTime> { /* * (non-Javadoc) * @see com.fasterxml.jackson.databind.JsonDeserializer#deserialize(com.fasterxml.jackson.core.JsonParser, com.fasterxml.jackson.databind.DeserializationContext) */ @Override public DateTime deserialize(final JsonParser parser, final DeserializationContext context) throws IOException, JsonProcessingException { try { return any().parseDateTime(parser.getText()); } catch (IllegalArgumentException e) { throw new JsonParseException("The date-time is invalid.", parser.getCurrentLocation(), e); } } } /** * <p> * A DateTimeParser that implements the W3C profile of the ISO 8601 * representation of dates and times * (<a href="http://www.w3.org/TR/NOTE-datetime"> * http://www.w3.org/TR/NOTE-datetime * </a>). * </p> * * <p> * The most common use-case of this library is through the * ISOW3CDateTimeFormat, which will create an instance of this parser. * * <pre>ISOW3CDateTimeFormat.dateTime();</pre> * * For date-only formats, the zone is set to UTC. Like all DateTimeParsers, * the zone information is overridden with JodaTime's default zone. If you * are creating this parser yourself and would like to preserve the zone, * be sure to call 'withOffsetParsed()' on the resulting parser. * * <pre>(new ISOW3CDateTimeParser()).withOffsetParsed();</pre> * * </p> * * @author John Jenkins */ public static class ISOW3CDateTimeParser implements DateTimeParser { /** * The date-time formatter for the W3C's specifications for date-only * values. */ private static final DateTimeParser ISO_W3C_DATE_PARSER; static { // The W3C defines 3 formats as valid ISO date values. DateTimeParser[] parsers = new DateTimeParser[3]; // Just the year. parsers[0] = ISOW3CDateTimeFormat.year().getParser(); // The year and month. parsers[1] = ISOW3CDateTimeFormat.yearMonth().getParser(); // The year, month, and day. parsers[2] = ISOW3CDateTimeFormat.yearMonthDay().getParser(); // Build the parser with the 3 sub-parsers. DateTimeFormatterBuilder builder = new DateTimeFormatterBuilder(); builder.append(null, parsers); ISO_W3C_DATE_PARSER = builder.toParser(); } /** * The date-time formatter for the W3C's specifications for date-time * values. */ private static final DateTimeParser ISO_W3C_DATE_TIME_PARSER; static { // The W3C defines 3 formats as valid ISO date-time values. DateTimeParser[] parsers = new DateTimeParser[3]; // The year, month, day, hour, minute, and time zone. // Build the parser from the existing ISODateTimeParser for the // year, month, day, hour, and minute and add the time zone. parsers[0] = ISOW3CDateTimeFormat.dateHourMinuteZone().getParser(); // The year, month, day, hour, minute, second, and time zone. parsers[1] = ISOW3CDateTimeFormat.dateHourMinuteSecondZone().getParser(); // The year, month, day, hour, minute, and time zone. // Build the parser from the existing ISODateTimeParser for the // year, month, day, hour, and minute and add the time zone. parsers[2] = ISOW3CDateTimeFormat.dateTime().getParser(); // Build the parser with the 3 sub-parsers. DateTimeFormatterBuilder builder = new DateTimeFormatterBuilder(); builder.append(null, parsers); ISO_W3C_DATE_TIME_PARSER = builder.toParser(); } /* * (non-Javadoc) * @see org.joda.time.format.DateTimeParser#estimateParsedLength() */ @Override public int estimateParsedLength() { return Math.max(ISO_W3C_DATE_PARSER.estimateParsedLength(), ISO_W3C_DATE_TIME_PARSER.estimateParsedLength()); } /* * (non-Javadoc) * @see org.joda.time.format.DateTimeParser#parseInto(org.joda.time.format.DateTimeParserBucket, java.lang.String, int) */ @Override public int parseInto(final DateTimeParserBucket bucket, final String text, final int position) { // Save the current state of the bucket. Object bucketState = bucket.saveState(); // Attempt to parse the text with the date-only parser. int newPosition = ISO_W3C_DATE_PARSER.parseInto(bucket, text, position); // If the parser returned a negative number, that represents an // error and should be propagated. if (newPosition < 0) { return newPosition; } // If the new position is the length of the text, then the entire // string was parsed. We must set the time zone to UTC for these // values. else if (newPosition == text.length()) { bucket.setZone(DateTimeZone.UTC); return newPosition; } // Otherwise, this parser is inadequate and we must reset the // bucket and use the other parser. else { // FIXME: This shouldn't be necessary, and we should be able to // just continue parsing where we left off. If that were the // case, then this Parser could be removed as could the any() // function in the ISOW3CDateTimeFormat function, and users // could create any combination of the ISOW3CDateTimeFormats. bucket.restoreState(bucketState); return ISO_W3C_DATE_TIME_PARSER.parseInto(bucket, text, position); } } } // Lazily instantiate the internal formatters. private static DateTimeFormatter year, yearMonth, yearMonthDay, yearMonthDayHourMinuteZone, yearMonthDayHourMinuteSecondZone, yearMonthDayHourMinuteSecondMillisZone, any; /** * Default constructor. Does nothing. */ protected ISOW3CDateTimeFormat() { super(); } /** * Returns a formatter for the four digit year with a time zone of UTC. * * @return A formatter for the year with a time zone of UTC. */ public static DateTimeFormatter year() { if (year == null) { year = ISODateTimeFormat.year().withZoneUTC(); } return year; } /** * Returns a formatter for the four digit year and two digit month of * the year with a time zone of UTC. * * @return A formatter for the year and month with a time zone of UTC. */ public static DateTimeFormatter yearMonth() { if (yearMonth == null) { yearMonth = ISODateTimeFormat.yearMonth().withZoneUTC(); } return yearMonth; } /** * Returns a formatter for the four digit year, two digit month of the * year, and two digit day of the month with a time zone of UTC. * * @return A formatter for the year, month, and day with a time zone of * UTC. */ public static DateTimeFormatter yearMonthDay() { if (yearMonthDay == null) { yearMonthDay = ISODateTimeFormat.yearMonthDay().withZoneUTC(); } return yearMonthDay; } /** * Returns a formatter for the four digit year, two digit month of the * year, and two digit day of the month with a time zone of UTC. * * @return A formatter for the year, month, and day with a time zone of * UTC. */ public static DateTimeFormatter date() { return yearMonthDay(); } /** * Returns a formatter that combines a full date, two digit hour of the * day, two digit minute of the hour and a time zone. * * @return A formatter for the date, hour, minute, and time zone. */ public static DateTimeFormatter dateHourMinuteZone() { if (yearMonthDayHourMinuteZone == null) { DateTimeFormatterBuilder dateHourMinuteTimezone = new DateTimeFormatterBuilder(); dateHourMinuteTimezone.append(ISODateTimeFormat.dateHourMinute()); dateHourMinuteTimezone.append(DateTimeFormat.forPattern("ZZ")); yearMonthDayHourMinuteZone = dateHourMinuteTimezone.toFormatter().withOffsetParsed(); } return yearMonthDayHourMinuteZone; } /** * Returns a formatter that combines a full date, two digit hour of the * day, two digit minute of the hour, two digit second of the minute * and a time zone. * * @return A formatter for the date, hour, minute, second, and time * zone. */ public static DateTimeFormatter dateHourMinuteSecondZone() { if (yearMonthDayHourMinuteSecondZone == null) { yearMonthDayHourMinuteSecondZone = ISODateTimeFormat.dateTimeNoMillis().withOffsetParsed(); } return yearMonthDayHourMinuteSecondZone; } /** * Returns a formatter that combines a full date, two digit hour of the * day, two digit minute of the hour, two digit second of the minute * and a time zone. * * @return A formatter for the date, hour, minute, second, and time * zone. */ public static DateTimeFormatter dateTimeNoMillis() { return dateHourMinuteSecondZone(); } /** * Returns a formatter that combines a full date, two digit hour of the * day, two digit minute of the hour, two digit second of the minute, * three digit milliseconds of the second and a time zone. * * @return A formatter for the date, hour, minute, second, millisecond, * and time zone. */ public static DateTimeFormatter dateHourMinuteSecondMillisZone() { if (yearMonthDayHourMinuteSecondMillisZone == null) { yearMonthDayHourMinuteSecondMillisZone = ISODateTimeFormat.dateTime().withOffsetParsed(); } return yearMonthDayHourMinuteSecondMillisZone; } /** * Returns a formatter that combines a full date, two digit hour of the * day, two digit minute of the hour, two digit second of the minute, * three digit milliseconds of the second and a time zone. * * @return A formatter for the date, hour, minute, second, millisecond, * and time zone. */ public static DateTimeFormatter dateTime() { return dateHourMinuteSecondMillisZone(); } /** * Returns a formatter that combines all ISOW3CDateTimeFormats. This * formatter will correctly parse any of the other formatters and will only * fail if the value doesn't match any of them. * * @return A universal DateTimeFormatter for all ISO W3C date-time formats. * * @see #year() * @see #yearMonth() * @see #yearMonthDay() * @see #dateHourMinuteZone() * @see #dateHourMinuteSecondZone() * @see #dateHourMinuteSecondMillisZone() */ public static DateTimeFormatter any() { if (any == null) { any = new DateTimeFormatter(ISODateTimeFormat.dateTime().getPrinter(), new ISOW3CDateTimeParser()) .withOffsetParsed(); } return any; } }