Java tutorial
/* * This is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * */ package org.rockholla.date; import java.util.ArrayList; import java.util.Calendar; import java.util.regex.Pattern; import org.joda.time.DateTime; import org.joda.time.format.DateTimeFormat; import org.joda.time.format.DateTimeFormatter; import org.rockholla.number.NumberUtility; /** * Helper class for Dates (utilizes Joda date time classes) * * @author rockholla * @see org.joda.time.DateTime * */ public class DateUtility { /** * Formats a datetime * * @param dateTime the org.joda.time.DateTime value to format * @param format the string format instruction * @return the formatted datetime */ public static String getFormattedDate(DateTime dateTime, String format) { DateTimeFormatter formatter = DateTimeFormat.forPattern(format); return formatter.print(dateTime); } /** * Formats the current date time * * @param format the string format instruction * @return the formatted datetime */ public static String getFormattedDate(String format) { DateTimeFormatter formatter = DateTimeFormat.forPattern(format); return formatter.print(new DateTime()); } /** * Formats a datetime for use in a MySQL datetime field * * @param dateTime the org.joda.time.DateTime value to format * @return the formatted datetime */ public static String getMySqlDate(DateTime dateTime) { return getMySqlDate(dateTime, 0); } /** * Formats a datetime for use in a MySQL datetime field * * @param dateTime the org.joda.time.DateTime value to format * @param offset offset the input datetime by this amount of hours * @return the formatted datetime */ public static String getMySqlDate(DateTime dateTime, int offset) { if (offset > 0 || offset < 0) { dateTime = dateTime.plusHours(offset); } String result = String.valueOf(dateTime.getYear()) + "-" + NumberUtility.format(dateTime.getMonthOfYear(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + "-" + NumberUtility.format(dateTime.getDayOfMonth(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + " " + NumberUtility.format(dateTime.getHourOfDay(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + ":" + NumberUtility.format(dateTime.getMinuteOfHour(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + ":" + NumberUtility.format(dateTime.getSecondOfMinute(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER); return result; } /** * Determines if the input CharSequence is a valid date representation * * @param date a CharSequence * @return true indicates the input sequence is a valid date */ public static Boolean isDate(CharSequence date) { // some regular expression String time = "(\\s(([01]?\\d)|(2[0123]))[:](([012345]\\d)|(60))" + "[:](([012345]\\d)|(60)))?"; // with a space before, zero or one time // no check for leap years (Schaltjahr) // and 31.02.2006 will also be correct String day = "(([12]\\d)|(3[01])|(0?[1-9])|([1-31]))"; // 01 up to 31 or 1 to 31 String month = "((1[012])|(0\\d)|([1-12]))"; // 01 up to 12 or 1 to 12 String year = "\\d{4}"; // define here all date format ArrayList<Pattern> patterns = new ArrayList<Pattern>(); patterns.add(Pattern.compile(day + "[\\-\\.]" + month + "[\\-\\.]" + year + time)); patterns.add(Pattern.compile(year + "\\-" + month + "\\-" + day + time)); // here you can add more date formats if you want patterns.add(Pattern.compile(day + "\\/" + month + "\\/" + year)); // check dates for (Pattern p : patterns) { if (p.matcher(date).matches()) { return true; } } return false; } /** * Gets the calendar date from a Julian day of a particular year * * @param dayOfYear the julian day * @param year the year * @return the org.joda.time.DateTime */ public static DateTime getDateFromDayOfYear(int dayOfYear, int year) { Calendar calendar = Calendar.getInstance(); calendar.set(Calendar.YEAR, year); calendar.set(Calendar.DAY_OF_YEAR, dayOfYear); return new DateTime(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH) + 1, calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0, 0); } /** * Returns a unique string based on a timestamp (DateTime must be precise to the second * to ensure uniqueness) * * @param dateTime the org.joda.time.DateTime to use to create the ID * @return a unique string representation of the date */ public static String getTimestampId(DateTime dateTime) { String id = ""; id = NumberUtility.format(dateTime.getYear(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + NumberUtility.format(dateTime.getMonthOfYear(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + NumberUtility.format(dateTime.getDayOfMonth(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + NumberUtility.format(dateTime.getHourOfDay(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + NumberUtility.format(dateTime.getMinuteOfHour(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + NumberUtility.format(dateTime.getSecondOfMinute(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER) + NumberUtility.format(dateTime.getMillisOfSecond(), NumberUtility.FORMAT.TWO_CHARACTER_INTEGER); return id; } }