Java tutorial
package com.cloudhopper.commons.util; /* * #%L * ch-commons-util * %% * Copyright (C) 2012 Cloudhopper by Twitter * %% * 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. * #L% */ import java.sql.Timestamp; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.joda.time.DateTime; import org.joda.time.DateTimeZone; import org.joda.time.format.DateTimeFormat; import org.joda.time.format.DateTimeFormatter; /** * * @author joelauer (twitter: @jjlauer or <a href="http://twitter.com/jjlauer" target=window>http://twitter.com/jjlauer</a>) */ public class DateTimeUtil { /** * Null-safe method of converting a SQL Timestamp into a DateTime that * it set specifically to be in UTC. * <br> * NOTE: The timestamp also should be in UTC. * @return A UTC DateTime */ public static DateTime toDateTime(Timestamp value) { if (value == null) { return null; } else { return new DateTime(value.getTime(), DateTimeZone.UTC); } } /** * Null-safe method of copying a DateTime * <br> * NOTE: The timestamp also should be in UTC. * @return A UTC DateTime */ public static DateTime copy(DateTime value) { if (value == null) { return null; } else { return new DateTime(value.getMillis(), DateTimeZone.UTC); } } /** * Null-safe method of converting a DateTime to a Timestamp. * <br> * NOTE: The timestamp also should be in UTC. * @return A UTC DateTime */ public static Timestamp toTimestamp(DateTime dt) { if (dt == null) { return null; } else { return new Timestamp(dt.getMillis()); } } /** * Get the current time as a DateTime. * * @return A UTC DateTime */ public static DateTime now() { return new DateTime(DateTimeZone.UTC); } /** * Parses a string for an embedded date and/or time contained within a * string such as "app.2008-05-01.log". This method expects the string * to contain a pattern of "yyyy-MM-dd". All dates will be interpreted to * be in the UTC timezone. * @param string0 The string to parse * @return The parsed DateTime value * @throws IllegalArgumentException Thrown if the string did not contain * an embedded date. */ public static DateTime parseEmbedded(String string0) throws IllegalArgumentException { return parseEmbedded(string0, "yyyy-MM-dd", DateTimeZone.UTC); } /** * Parses a string for an embedded date and/or time contained within a * string such as "app.2008-05-01.log" or "app-20090624-051112.log.gz". * This method accepts a variety of date and time patterns that are valid * within the Joda DateTime library. For example, the string "app.2008-05-01.log" * would be a pattern of "yyyy-MM-dd" and the string "app-20090624-151112.log.gz" * would be a pattern of "yyyy-MM-dd-HHmmss". * @param string0 The string to parse * @param pattern The DateTime pattern embedded in the string such as * "yyyy-MM-dd". The pattern must be a valid DateTime Joda pattern. * @param zone The timezone the parsed date will be in * @return The parsed DateTime value * @throws IllegalArgumentException Thrown if the pattern is invalid or if * string did not contain an embedded date. */ public static DateTime parseEmbedded(String string0, String pattern, DateTimeZone zone) throws IllegalArgumentException { // compile a date time formatter -- which also will check that pattern DateTimeFormatter fmt = DateTimeFormat.forPattern(pattern).withZone(zone); // // use the pattern to generate a regular expression now -- we'll do a // simple replacement of ascii characters with \\d // StringBuilder regex = new StringBuilder(pattern.length() * 2); for (int i = 0; i < pattern.length(); i++) { char c = pattern.charAt(i); if (Character.isLetter(c)) { regex.append("\\d"); } else { regex.append(c); } } // extract the date from the string Pattern p = Pattern.compile(regex.toString()); // Compiles regular expression into Pattern. Matcher m = p.matcher(string0); // Creates Matcher with subject s and Pattern p. if (!m.find()) { // if we get here, then no valid grouping was found throw new IllegalArgumentException( "String '" + string0 + "' did not contain an embedded date [regexPattern='" + regex.toString() + "', datePattern='" + pattern + "']"); } //logger.debug("Matching date: " + m.group()); // this group represents a string in the format YYYY-MM-DD String dateString = m.group(); // parse the string and return the Date return fmt.parseDateTime(dateString); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest year. Note that the nearest valid year is actually * the first of that given year (Jan 1). The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-01-01 00:00:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest year. */ public static DateTime floorToYear(DateTime value) { if (value == null) { return null; } return new DateTime(value.getYear(), 1, 1, 0, 0, 0, 0, value.getZone()); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest month. Note that the nearest valid month is actually * the first of that given month (1st day of month). The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-06-01 00:00:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest month. */ public static DateTime floorToMonth(DateTime value) { if (value == null) { return null; } return new DateTime(value.getYear(), value.getMonthOfYear(), 1, 0, 0, 0, 0, value.getZone()); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest day. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-06-24 00:00:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest day. */ public static DateTime floorToDay(DateTime value) { if (value == null) { return null; } return new DateTime(value.getYear(), value.getMonthOfYear(), value.getDayOfMonth(), 0, 0, 0, 0, value.getZone()); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest hour. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-06-24 13:00:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest hour. */ public static DateTime floorToHour(DateTime value) { if (value == null) { return null; } return new DateTime(value.getYear(), value.getMonthOfYear(), value.getDayOfMonth(), value.getHourOfDay(), 0, 0, 0, value.getZone()); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest half hour (30 minutes). The time zone of the * returned DateTime instance will be the same as the argument. Similar to a * floor() function on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:29:51.476 -8:00" -> "2009-06-24 13:00:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest 30 minutes. */ public static DateTime floorToHalfHour(DateTime value) { return floorToMinutePeriod(value, 30); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest 15 minutes. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:29:51.476 -8:00" -> "2009-06-24 13:15:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest 15 minutes. */ public static DateTime floorToQuarterHour(DateTime value) { return floorToMinutePeriod(value, 15); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest 10 minutes. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:29:51.476 -8:00" -> "2009-06-24 13:20:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest 10 minutes. */ public static DateTime floorToTenMinutes(DateTime value) { return floorToMinutePeriod(value, 10); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest 5 minutes. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-06-24 13:20:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest 5 minutes. */ public static DateTime floorToFiveMinutes(DateTime value) { return floorToMinutePeriod(value, 5); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest specified period in minutes. For example, if * a period of 5 minutes is requested, a time of "2009-06-24 13:24:51.476 -8:00" * would return a datetime of "2009-06-24 13:20:00.000 -8:00". The time zone of the * returned DateTime instance will be the same as the argument. Similar to a * floor() function on a float.<br> * NOTE: While any period in minutes between 1 and 59 can be passed into this * method, its only useful if the value can be evenly divided into 60 to make * it as useful as possible.<br> * Examples: * <ul> * <li>null -> null * <li>5: "2009-06-24 13:39:51.476 -8:00" -> "2009-06-24 13:35:00.000 -8:00" * <li>10: "2009-06-24 13:39:51.476 -8:00" -> "2009-06-24 13:30:00.000 -8:00" * <li>15: "2009-06-24 13:39:51.476 -8:00" -> "2009-06-24 13:30:00.000 -8:00" * <li>20: "2009-06-24 13:39:51.476 UTC" -> "2009-06-24 13:20:00.000 UTC" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest period in minutes. */ public static DateTime floorToMinutePeriod(DateTime value, int periodInMinutes) { if (value == null) { return null; } if (periodInMinutes <= 0 || periodInMinutes > 59) { throw new IllegalArgumentException("period in minutes must be > 0 and <= 59"); } int min = value.getMinuteOfHour(); min = (min / periodInMinutes) * periodInMinutes; return new DateTime(value.getYear(), value.getMonthOfYear(), value.getDayOfMonth(), value.getHourOfDay(), min, 0, 0, value.getZone()); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest minute. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-06-24 13:24:00.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest minute. */ public static DateTime floorToMinute(DateTime value) { if (value == null) { return null; } return new DateTime(value.getYear(), value.getMonthOfYear(), value.getDayOfMonth(), value.getHourOfDay(), value.getMinuteOfHour(), 0, 0, value.getZone()); } /** * Null-safe method that returns a new instance of a DateTime object rounded * downwards to the nearest second. The time zone of the returned DateTime * instance will be the same as the argument. Similar to a floor() function * on a float.<br> * Examples: * <ul> * <li>null -> null * <li>"2009-06-24 13:24:51.476 -8:00" -> "2009-06-24 13:24:51.000 -8:00" * </ul> * @param value The DateTime value to round downward * @return Null if the argument is null or a new instance of the DateTime * value rounded downwards to the nearest second. */ public static DateTime floorToSecond(DateTime value) { if (value == null) { return null; } return new DateTime(value.getYear(), value.getMonthOfYear(), value.getDayOfMonth(), value.getHourOfDay(), value.getMinuteOfHour(), value.getSecondOfMinute(), 0, value.getZone()); } }