Here you can find the source of isValidDate(String dateString)
| Parameter | Description |
|---|---|
| dateString | The date string. |
public static boolean isValidDate(String dateString)
//package com.java2s; /*// w w w .ja v a 2 s .co m * net/balusc/util/DateUtil.java * * Copyright (C) 2007 BalusC * * This program 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 2 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. */ import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Date; import java.util.HashMap; import java.util.Map; public class Main { private static final Map<String, String> DATE_FORMAT_REGEXPS = new HashMap<String, String>() { { put("^\\d{8}$", "yyyyMMdd"); put("^\\d{1,2}-\\d{1,2}-\\d{4}$", "dd-MM-yyyy"); put("^\\d{4}-\\d{1,2}-\\d{1,2}$", "yyyy-MM-dd"); put("^\\d{1,2}/\\d{1,2}/\\d{4}$", "MM/dd/yyyy"); put("^\\d{4}/\\d{1,2}/\\d{1,2}$", "yyyy/MM/dd"); put("^\\d{1,2}\\s[a-z]{3}\\s\\d{4}$", "dd MMM yyyy"); put("^\\d{1,2}\\s[a-z]{4,}\\s\\d{4}$", "dd MMMM yyyy"); put("^\\d{12}$", "yyyyMMddHHmm"); put("^\\d{8}\\s\\d{4}$", "yyyyMMdd HHmm"); put("^\\d{1,2}-\\d{1,2}-\\d{4}\\s\\d{1,2}:\\d{2}$", "dd-MM-yyyy HH:mm"); put("^\\d{4}-\\d{1,2}-\\d{1,2}\\s\\d{1,2}:\\d{2}$", "yyyy-MM-dd HH:mm"); put("^\\d{1,2}/\\d{1,2}/\\d{4}\\s\\d{1,2}:\\d{2}$", "MM/dd/yyyy HH:mm"); put("^\\d{4}/\\d{1,2}/\\d{1,2}\\s\\d{1,2}:\\d{2}$", "yyyy/MM/dd HH:mm"); put("^\\d{1,2}\\s[a-z]{3}\\s\\d{4}\\s\\d{1,2}:\\d{2}$", "dd MMM yyyy HH:mm"); put("^\\d{1,2}\\s[a-z]{4,}\\s\\d{4}\\s\\d{1,2}:\\d{2}$", "dd MMMM yyyy HH:mm"); put("^\\d{14}$", "yyyyMMddHHmmss"); put("^\\d{8}\\s\\d{6}$", "yyyyMMdd HHmmss"); put("^\\d{1,2}-\\d{1,2}-\\d{4}\\s\\d{1,2}:\\d{2}:\\d{2}$", "dd-MM-yyyy HH:mm:ss"); put("^\\d{4}-\\d{1,2}-\\d{1,2}\\s\\d{1,2}:\\d{2}:\\d{2}$", "yyyy-MM-dd HH:mm:ss"); put("^\\d{1,2}/\\d{1,2}/\\d{4}\\s\\d{1,2}:\\d{2}:\\d{2}$", "MM/dd/yyyy HH:mm:ss"); put("^\\d{4}/\\d{1,2}/\\d{1,2}\\s\\d{1,2}:\\d{2}:\\d{2}$", "yyyy/MM/dd HH:mm:ss"); put("^\\d{1,2}\\s[a-z]{3}\\s\\d{4}\\s\\d{1,2}:\\d{2}:\\d{2}$", "dd MMM yyyy HH:mm:ss"); put("^\\d{1,2}\\s[a-z]{4,}\\s\\d{4}\\s\\d{1,2}:\\d{2}:\\d{2}$", "dd MMMM yyyy HH:mm:ss"); put("^\\d{4},\\d{4}-\\d{1,2}-\\d{1,2}$", "yyyy,yyyy-MM-dd"); put("^\\d{4},\\d{4}-\\d{1,2}$", "yyyy,yyyy-MM"); put("^\\d{4}$", "yyyy"); put("^\\d{4},\\d{4}$", "yyyy,yyyy"); put("^\\d{4}-\\d{1,2}$", "yyyy-MM"); put("^\\d{4}-\\d{1,2},\\d{4}-\\d{1,2}-\\d{1,2}$", "yyyy-MM,yyyy-MM-dd"); put("^\\d{4}-\\d{1,2},\\d{4}-\\d{1,2}$", "yyyy-MM,yyyy-MM"); put("^\\d{4}-\\d{1,2}-\\d{1,2},\\d{4}-\\d{1,2}-\\d{1,2}$", "yyyy-MM-dd,yyyy-MM-dd"); put("^\\d{4}-\\d{1,2}-\\d{1,2},\\d{4}$", "yyyy-MM-dd,yyyy"); put("^\\d{4}-\\d{1,2}-\\d{1,2},\\d{4},\\d{4}$", "yyyy-MM-dd,yyyy,yyyy"); put("^\\d{4}-\\d{1,2}-\\d{1,2},\\d{4}-\\d{1,2}$", "yyyy-MM-dd,yyyy-MM"); } }; /** * Checks whether the actual date of the given date string is valid. This * makes use of the {@link DateUtil#determineDateFormat(String)} to * determine the SimpleDateFormat pattern to be used for parsing. * * @param dateString * The date string. * @return True if the actual date of the given date string is valid. */ public static boolean isValidDate(String dateString) { try { parse(dateString); return true; } catch (ParseException e) { return false; } } /** * Checks whether the actual date of the given date string is valid based on * the given date format pattern. * * @param dateString * The date string. * @param dateFormat * The date format pattern which should respect the * SimpleDateFormat rules. * @return True if the actual date of the given date string is valid based * on the given date format pattern. * @see SimpleDateFormat */ public static boolean isValidDate(String dateString, String dateFormat) { try { parse(dateString, dateFormat); return true; } catch (ParseException e) { return false; } } /** * Parse the given date string to date object and return a date instance * based on the given date string. This makes use of the * {@link DateUtil#determineDateFormat(String)} to determine the * SimpleDateFormat pattern to be used for parsing. * * @param dateString * The date string to be parsed to date object. * @return The parsed date object. * @throws ParseException * If the date format pattern of the given date string is * unknown, or if the given date string or its actual date is * invalid based on the date format pattern. */ public static Date parse(String dateString) throws ParseException { String dateFormat = determineDateFormat(dateString); if (dateFormat == null) { throw new ParseException("Unknown date format.", 0); } return parse(dateString, dateFormat); } /** * Validate the actual date of the given date string based on the given date * format pattern and return a date instance based on the given date string. * * @param dateString * The date string. * @param dateFormat * The date format pattern which should respect the * SimpleDateFormat rules. * @return The parsed date object. * @throws ParseException * If the given date string or its actual date is invalid based * on the given date format pattern. * @see SimpleDateFormat */ public static Date parse(String dateString, String dateFormat) throws ParseException { SimpleDateFormat simpleDateFormat = new SimpleDateFormat(dateFormat); simpleDateFormat.setLenient(false); // Don't automatically convert // invalid date. return simpleDateFormat.parse(dateString); } /** * Determine SimpleDateFormat pattern matching with the given date string. * Returns null if format is unknown. You can simply extend DateUtil with * more formats if needed. * * @param dateString * The date string to determine the SimpleDateFormat pattern for. * @return The matching SimpleDateFormat pattern, or null if format is * unknown. * @see SimpleDateFormat */ public static String determineDateFormat(String dateString) { for (String regexp : DATE_FORMAT_REGEXPS.keySet()) { if (dateString.toLowerCase().matches(regexp)) { return DATE_FORMAT_REGEXPS.get(regexp); } } return null; // Unknown format. } }