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Javaの正規表現の日付形式の検証

Javaデスクトップアプリへの入力が「YYYY-MM-DD」という形式の文字列であることを検証する方法(正規表現を使用する場合など)があるかどうか疑問に思っています。

検索しましたが、成功しませんでした。

ありがとうございました

55
Sheldon

次の正規表現を使用します。

^\d{4}-\d{2}-\d{2}$

のように

if (str.matches("\\d{4}-\\d{2}-\\d{2}")) {
    ...
}

matchesメソッドでは、アンカー^および$(それぞれ文字列の先頭と末尾)が暗黙的に存在します。

78
Greg Bacon

regex以上が必要です。たとえば、「9999-99-00」は有効な日付ではありません。これを行うために構築されたSimpleDateFormatクラスがあります。より重いが、より包括的な。

例えば.

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

boolean isValidDate(string input) {
     try {
          format.parse(input);
          return true;
     }
     catch(ParseException e){
          return false;
     }
}

残念ながら、SimpleDateFormatは重量級であり、スレッドセーフではありません。

29
Steve B.

すべてを一緒に入れて:

  • REGEXは値を検証しません( "2010-19-19"など)
  • SimpleDateFormatは形式をチェックしません( "2010-1-2"、 "1-0002-003"は受け入れられます)

形式と値を検証するために両方を使用する必要があります。

public static boolean isValid(String text) {
    if (text == null || !text.matches("\\d{4}-[01]\\d-[0-3]\\d"))
        return false;
    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
    df.setLenient(false);
    try {
        df.parse(text);
        return true;
    } catch (ParseException ex) {
        return false;
    }
}




private static final ThreadLocal<SimpleDateFormat> format = new ThreadLocal<SimpleDateFormat>() {
    @Override
    protected SimpleDateFormat initialValue() {
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
        df.setLenient(false);
        System.out.println("created");
        return df;
    }
};

public static boolean isValid(String text) {
    if (text == null || !text.matches("\\d{4}-[01]\\d-[0-3]\\d"))
        return false;
    try {
        format.get().parse(text);
        return true;
    } catch (ParseException ex) {
        return false;
    }
}

(Matcherでも同じことができますが、これもスレッドセーフではありません)

22

これにより、正規表現が実行されます。"^((19|20)\\d\\d)-(0?[1-9]|1[012])-(0?[1-9]|[12][0-9]|3[01])$"これにより、有効な形式と有効な日付が処理されます。月の正しい日、つまりうるう年は検証されません。

String regex = "^((19|20)\\d\\d)-(0?[1-9]|1[012])-(0?[1-9]|[12][0-9]|3[01])$";

Assert.assertTrue("Date: matched.", Pattern.matches(regex, "2011-1-1"));
Assert.assertFalse("Date (month): not matched.", Pattern.matches(regex, "2011-13-1"));

幸運を!

11
CKuharski

単純な正規表現を使用して、日が31日を超えないこと、および月が12日を超えないことを確認します。

(0?[1-9]|[12][0-9]|3[01])-(0?[1-9]|1[012])-((18|19|20|21)\\d\\d)

これは「dd-MM-yyyy」の形式です。ニーズに合わせて微調整することができます(たとえば、?を外して先頭の0を必須にします-現在はオプションです)。その後、カスタムロジックを使用して、うるう年2月の日数などの特定のルールを削減できます。日数の月数。以下のDateCheckerコードを参照してください。

パフォーマンスを考慮した場合、これが最良のアプローチであるとテストしたため、このアプローチを選択しています。この(1番目の)アプローチと、他のユースケースを処理する正規表現に対して日付を検証する2番目のアプローチと、SimpleDateFormat.parse(date)と組み合わせて上記と同じ単純な正規表現を使用する3番目のアプローチを比較しました。
1番目のアプローチは2番目のアプローチより4倍、3番目のアプローチより8倍高速でした。下部にある自己完結型の日付チェッカーとパフォーマンステスターのメインクラスを参照してください。私が未チェックのままにしたことの1つは、joda時間アプローチです。 (より効率的な日付/時刻ライブラリ)。

日付チェッカーコード:

class DateChecker {

    private Matcher matcher;
    private Pattern pattern;

    public DateChecker(String regex) {
        pattern = Pattern.compile(regex);
    }

    /**
     * Checks if the date format is a valid.
     * Uses the regex pattern to match the date first. 
     * Than additionally checks are performed on the boundaries of the days taken the month into account (leap years are covered).
     * 
     * @param date the date that needs to be checked.
     * @return if the date is of an valid format or not.
     */
    public boolean check(final String date) {
        matcher = pattern.matcher(date);
        if (matcher.matches()) {
            matcher.reset();
            if (matcher.find()) {
                int day = Integer.parseInt(matcher.group(1));
                int month = Integer.parseInt(matcher.group(2));
                int year = Integer.parseInt(matcher.group(3));

                switch (month) {
                case 1:
                case 3:
                case 5:
                case 7:
                case 8:
                case 10:
                case 12: return day < 32;
                case 4:
                case 6:
                case 9:
                case 11: return day < 31;
                case 2: 
                    int modulo100 = year % 100;
                    //http://science.howstuffworks.com/science-vs-myth/everyday-myths/question50.htm
                    if ((modulo100 == 0 && year % 400 == 0) || (modulo100 != 0 && year % LEAP_STEP == 0)) {
                        //its a leap year
                        return day < 30;
                    } else {
                        return day < 29;
                    }
                default:
                    break;
                }
            }
        }
        return false;
    }

    public String getRegex() {
        return pattern.pattern();
    }
}

日付チェック/テストおよびパフォーマンステスト:

import Java.text.ParseException;
import Java.text.SimpleDateFormat;
import Java.util.ArrayList;
import Java.util.List;
import Java.util.regex.Matcher;
import Java.util.regex.Pattern;

public class Tester {

    private static final String[] validDateStrings = new String[]{
        "1-1-2000", //leading 0s for day and month optional
        "01-1-2000", //leading 0 for month only optional
        "1-01-2000", //leading 0 for day only optional
        "01-01-1800", //first accepted date
        "31-12-2199", //last accepted date
        "31-01-2000", //January has 31 days
        "31-03-2000", //March has 31 days
        "31-05-2000", //May has 31 days
        "31-07-2000", //July has 31 days
        "31-08-2000", //August has 31 days
        "31-10-2000", //October has 31 days
        "31-12-2000", //December has 31 days
        "30-04-2000", //April has 30 days
        "30-06-2000", //June has 30 days
        "30-09-2000", //September has 30 days
        "30-11-2000", //November has 30 days
    };
    private static final String[] invalidDateStrings = new String[]{
        "00-01-2000", //there is no 0-th day
        "01-00-2000", //there is no 0-th month
        "31-12-1799", //out of lower boundary date
        "01-01-2200", //out of high boundary date
        "32-01-2000", //January doesn't have 32 days
        "32-03-2000", //March doesn't have 32 days
        "32-05-2000", //May doesn't have 32 days
        "32-07-2000", //July doesn't have 32 days
        "32-08-2000", //August doesn't have 32 days
        "32-10-2000", //October doesn't have 32 days
        "32-12-2000", //December doesn't have 32 days
        "31-04-2000", //April doesn't have 31 days
        "31-06-2000", //June doesn't have 31 days
        "31-09-2000", //September doesn't have 31 days
        "31-11-2000", //November doesn't have 31 days
        "001-02-2000", //SimpleDateFormat valid date (day with leading 0s) even with lenient set to false
        "1-0002-2000", //SimpleDateFormat valid date (month with leading 0s) even with lenient set to false
        "01-02-0003", //SimpleDateFormat valid date (year with leading 0s) even with lenient set to false
        "01.01-2000", //. invalid separator between day and month
        "01-01.2000", //. invalid separator between month and year
        "01/01-2000", /// invalid separator between day and month
        "01-01/2000", /// invalid separator between month and year
        "01_01-2000", //_ invalid separator between day and month
        "01-01_2000", //_ invalid separator between month and year
        "01-01-2000-12345", //only whole string should be matched
        "01-13-2000", //month bigger than 13
    };

    /**
     * These constants will be used to generate the valid and invalid boundary dates for the leap years. (For no leap year, Feb. 28 valid and Feb. 29 invalid; for a leap year Feb. 29 valid and Feb. 30 invalid)   
     */
    private static final int LEAP_STEP = 4;
    private static final int YEAR_START = 1800;
    private static final int YEAR_END = 2199;

    /**
     * This date regex will find matches for valid dates between 1800 and 2199 in the format of "dd-MM-yyyy".
     * The leading 0 is optional.
     */
    private static final String DATE_REGEX = "((0?[1-9]|[12][0-9]|3[01])-(0?[13578]|1[02])-(18|19|20|21)[0-9]{2})|((0?[1-9]|[12][0-9]|30)-(0?[469]|11)-(18|19|20|21)[0-9]{2})|((0?[1-9]|1[0-9]|2[0-8])-(0?2)-(18|19|20|21)[0-9]{2})|(29-(0?2)-(((18|19|20|21)(04|08|[2468][048]|[13579][26]))|2000))";

    /**
     * This date regex is similar to the first one, but with the difference of matching only the whole string. So "01-01-2000-12345" won't pass with a match.
     * Keep in mind that String.matches tries to match only the whole string.
     */
    private static final String DATE_REGEX_ONLY_WHOLE_STRING = "^" + DATE_REGEX + "$";

    /**
     * The simple regex (without checking for 31 day months and leap years):
     */
    private static final String DATE_REGEX_SIMPLE = "(0?[1-9]|[12][0-9]|3[01])-(0?[1-9]|1[012])-((18|19|20|21)\\d\\d)";

    /**
     * This date regex is similar to the first one, but with the difference of matching only the whole string. So "01-01-2000-12345" won't pass with a match.
     */
    private static final String DATE_REGEX_SIMPLE_ONLY_WHOLE_STRING = "^" + DATE_REGEX_SIMPLE + "$";

    private static final SimpleDateFormat SDF = new SimpleDateFormat("dd-MM-yyyy");
    static {
        SDF.setLenient(false);
    }

    private static final DateChecker dateValidatorSimple = new DateChecker(DATE_REGEX_SIMPLE);
    private static final DateChecker dateValidatorSimpleOnlyWholeString = new DateChecker(DATE_REGEX_SIMPLE_ONLY_WHOLE_STRING);

    /**
     * @param args
     */
    public static void main(String[] args) {
        DateTimeStatistics dateTimeStatistics = new DateTimeStatistics();
        boolean shouldMatch = true;
        for (int i = 0; i < validDateStrings.length; i++) {
            String validDate = validDateStrings[i];
            matchAssertAndPopulateTimes(
                    dateTimeStatistics,
                    shouldMatch, validDate);
        }

        shouldMatch = false;
        for (int i = 0; i < invalidDateStrings.length; i++) {
            String invalidDate = invalidDateStrings[i];

            matchAssertAndPopulateTimes(dateTimeStatistics,
                    shouldMatch, invalidDate);
        }

        for (int year = YEAR_START; year < (YEAR_END + 1); year++) {
            FebruaryBoundaryDates februaryBoundaryDates = createValidAndInvalidFebruaryBoundaryDateStringsFromYear(year);
            shouldMatch = true;
            matchAssertAndPopulateTimes(dateTimeStatistics,
                    shouldMatch, februaryBoundaryDates.getValidFebruaryBoundaryDateString());
            shouldMatch = false;
            matchAssertAndPopulateTimes(dateTimeStatistics,
                    shouldMatch, februaryBoundaryDates.getInvalidFebruaryBoundaryDateString());
        }

        dateTimeStatistics.calculateAvarageTimesAndPrint();
    }

    private static void matchAssertAndPopulateTimes(
            DateTimeStatistics dateTimeStatistics,
            boolean shouldMatch, String date) {
        dateTimeStatistics.addDate(date);
        matchAndPopulateTimeToMatch(date, DATE_REGEX, shouldMatch, dateTimeStatistics.getTimesTakenWithDateRegex());
        matchAndPopulateTimeToMatch(date, DATE_REGEX_ONLY_WHOLE_STRING, shouldMatch, dateTimeStatistics.getTimesTakenWithDateRegexOnlyWholeString());
        boolean matchesSimpleDateFormat = matchWithSimpleDateFormatAndPopulateTimeToMatchAndReturnMatches(date, dateTimeStatistics.getTimesTakenWithSimpleDateFormatParse());
        matchAndPopulateTimeToMatchAndReturnMatchesAndCheck(
                dateTimeStatistics.getTimesTakenWithDateRegexSimple(), shouldMatch,
                date, matchesSimpleDateFormat, DATE_REGEX_SIMPLE);
        matchAndPopulateTimeToMatchAndReturnMatchesAndCheck(
                dateTimeStatistics.getTimesTakenWithDateRegexSimpleOnlyWholeString(), shouldMatch,
                date, matchesSimpleDateFormat, DATE_REGEX_SIMPLE_ONLY_WHOLE_STRING);

        matchAndPopulateTimeToMatch(date, dateValidatorSimple, shouldMatch, dateTimeStatistics.getTimesTakenWithdateValidatorSimple());
        matchAndPopulateTimeToMatch(date, dateValidatorSimpleOnlyWholeString, shouldMatch, dateTimeStatistics.getTimesTakenWithdateValidatorSimpleOnlyWholeString());
    }

    private static void matchAndPopulateTimeToMatchAndReturnMatchesAndCheck(
            List<Long> times,
            boolean shouldMatch, String date, boolean matchesSimpleDateFormat, String regex) {
        boolean matchesFromRegex = matchAndPopulateTimeToMatchAndReturnMatches(date, regex, times);
        assert !((matchesSimpleDateFormat && matchesFromRegex) ^ shouldMatch) : "Parsing with SimpleDateFormat and date:" + date + "\nregex:" + regex + "\nshouldMatch:" + shouldMatch;
    }

    private static void matchAndPopulateTimeToMatch(String date, String regex, boolean shouldMatch, List<Long> times) {
        boolean matches = matchAndPopulateTimeToMatchAndReturnMatches(date, regex, times);
        assert !(matches ^ shouldMatch) : "date:" + date + "\nregex:" + regex + "\nshouldMatch:" + shouldMatch;
    }

    private static void matchAndPopulateTimeToMatch(String date, DateChecker dateValidator, boolean shouldMatch, List<Long> times) {
        long timestampStart;
        long timestampEnd;
        boolean matches;
        timestampStart = System.nanoTime();
        matches = dateValidator.check(date);
        timestampEnd = System.nanoTime();
        times.add(timestampEnd - timestampStart);
        assert !(matches ^ shouldMatch) : "date:" + date + "\ndateValidator with regex:" + dateValidator.getRegex() + "\nshouldMatch:" + shouldMatch;
    }

    private static boolean matchAndPopulateTimeToMatchAndReturnMatches(String date, String regex, List<Long> times) {
        long timestampStart;
        long timestampEnd;
        boolean matches;
        timestampStart = System.nanoTime();
        matches = date.matches(regex);
        timestampEnd = System.nanoTime();
        times.add(timestampEnd - timestampStart);
        return matches;
    }

    private static boolean matchWithSimpleDateFormatAndPopulateTimeToMatchAndReturnMatches(String date, List<Long> times) {
        long timestampStart;
        long timestampEnd;
        boolean matches = true;
        timestampStart = System.nanoTime();
        try {
            SDF.parse(date);
        } catch (ParseException e) {
            matches = false;
        } finally {
            timestampEnd = System.nanoTime();
            times.add(timestampEnd - timestampStart);
        }
        return matches;
    }

    private static FebruaryBoundaryDates createValidAndInvalidFebruaryBoundaryDateStringsFromYear(int year) {
        FebruaryBoundaryDates februaryBoundaryDates;
        int modulo100 = year % 100;
        //http://science.howstuffworks.com/science-vs-myth/everyday-myths/question50.htm
        if ((modulo100 == 0 && year % 400 == 0) || (modulo100 != 0 && year % LEAP_STEP == 0)) {
            februaryBoundaryDates = new FebruaryBoundaryDates(
                    createFebruaryDateFromDayAndYear(29, year), 
                    createFebruaryDateFromDayAndYear(30, year)
                    );
        } else {
            februaryBoundaryDates = new FebruaryBoundaryDates(
                    createFebruaryDateFromDayAndYear(28, year), 
                    createFebruaryDateFromDayAndYear(29, year)
                    );
        }
        return februaryBoundaryDates;
    }

    private static String createFebruaryDateFromDayAndYear(int day, int year) {
        return String.format("%d-02-%d", day, year);
    }

    static class FebruaryBoundaryDates {
        private String validFebruaryBoundaryDateString;
        String invalidFebruaryBoundaryDateString;
        public FebruaryBoundaryDates(String validFebruaryBoundaryDateString,
                String invalidFebruaryBoundaryDateString) {
            super();
            this.validFebruaryBoundaryDateString = validFebruaryBoundaryDateString;
            this.invalidFebruaryBoundaryDateString = invalidFebruaryBoundaryDateString;
        }
        public String getValidFebruaryBoundaryDateString() {
            return validFebruaryBoundaryDateString;
        }
        public void setValidFebruaryBoundaryDateString(
                String validFebruaryBoundaryDateString) {
            this.validFebruaryBoundaryDateString = validFebruaryBoundaryDateString;
        }
        public String getInvalidFebruaryBoundaryDateString() {
            return invalidFebruaryBoundaryDateString;
        }
        public void setInvalidFebruaryBoundaryDateString(
                String invalidFebruaryBoundaryDateString) {
            this.invalidFebruaryBoundaryDateString = invalidFebruaryBoundaryDateString;
        }
    }

    static class DateTimeStatistics {
        private List<String> dates = new ArrayList<String>();
        private List<Long> timesTakenWithDateRegex = new ArrayList<Long>();
        private List<Long> timesTakenWithDateRegexOnlyWholeString = new ArrayList<Long>();
        private List<Long> timesTakenWithDateRegexSimple = new ArrayList<Long>();
        private List<Long> timesTakenWithDateRegexSimpleOnlyWholeString = new ArrayList<Long>();
        private List<Long> timesTakenWithSimpleDateFormatParse = new ArrayList<Long>();
        private List<Long> timesTakenWithdateValidatorSimple = new ArrayList<Long>();
        private List<Long> timesTakenWithdateValidatorSimpleOnlyWholeString = new ArrayList<Long>();
        public List<String> getDates() {
            return dates;
        }
        public List<Long> getTimesTakenWithDateRegex() {
            return timesTakenWithDateRegex;
        }
        public List<Long> getTimesTakenWithDateRegexOnlyWholeString() {
            return timesTakenWithDateRegexOnlyWholeString;
        }
        public List<Long> getTimesTakenWithDateRegexSimple() {
            return timesTakenWithDateRegexSimple;
        }
        public List<Long> getTimesTakenWithDateRegexSimpleOnlyWholeString() {
            return timesTakenWithDateRegexSimpleOnlyWholeString;
        }
        public List<Long> getTimesTakenWithSimpleDateFormatParse() {
            return timesTakenWithSimpleDateFormatParse;
        }
        public List<Long> getTimesTakenWithdateValidatorSimple() {
            return timesTakenWithdateValidatorSimple;
        }
        public List<Long> getTimesTakenWithdateValidatorSimpleOnlyWholeString() {
            return timesTakenWithdateValidatorSimpleOnlyWholeString;
        }
        public void addDate(String date) {
            dates.add(date);
        }
        public void addTimesTakenWithDateRegex(long time) {
            timesTakenWithDateRegex.add(time);
        }
        public void addTimesTakenWithDateRegexOnlyWholeString(long time) {
            timesTakenWithDateRegexOnlyWholeString.add(time);
        }
        public void addTimesTakenWithDateRegexSimple(long time) {
            timesTakenWithDateRegexSimple.add(time);
        }
        public void addTimesTakenWithDateRegexSimpleOnlyWholeString(long time) {
            timesTakenWithDateRegexSimpleOnlyWholeString.add(time);
        }
        public void addTimesTakenWithSimpleDateFormatParse(long time) {
            timesTakenWithSimpleDateFormatParse.add(time);
        }
        public void addTimesTakenWithdateValidatorSimple(long time) {
            timesTakenWithdateValidatorSimple.add(time);
        }
        public void addTimesTakenWithdateValidatorSimpleOnlyWholeString(long time) {
            timesTakenWithdateValidatorSimpleOnlyWholeString.add(time);
        }

        private void calculateAvarageTimesAndPrint() {
            long[] sumOfTimes = new long[7];
            int timesSize = timesTakenWithDateRegex.size();
            for (int i = 0; i < timesSize; i++) {
                sumOfTimes[0] += timesTakenWithDateRegex.get(i);
                sumOfTimes[1] += timesTakenWithDateRegexOnlyWholeString.get(i);
                sumOfTimes[2] += timesTakenWithDateRegexSimple.get(i);
                sumOfTimes[3] += timesTakenWithDateRegexSimpleOnlyWholeString.get(i);
                sumOfTimes[4] += timesTakenWithSimpleDateFormatParse.get(i);
                sumOfTimes[5] += timesTakenWithdateValidatorSimple.get(i);
                sumOfTimes[6] += timesTakenWithdateValidatorSimpleOnlyWholeString.get(i);
            }
            System.out.println("AVG from timesTakenWithDateRegex (in nanoseconds):" + (double) sumOfTimes[0] / timesSize);
            System.out.println("AVG from timesTakenWithDateRegexOnlyWholeString (in nanoseconds):" + (double) sumOfTimes[1] / timesSize);
            System.out.println("AVG from timesTakenWithDateRegexSimple (in nanoseconds):" + (double) sumOfTimes[2] / timesSize);
            System.out.println("AVG from timesTakenWithDateRegexSimpleOnlyWholeString (in nanoseconds):" + (double) sumOfTimes[3] / timesSize);
            System.out.println("AVG from timesTakenWithSimpleDateFormatParse (in nanoseconds):" + (double) sumOfTimes[4] / timesSize);
            System.out.println("AVG from timesTakenWithDateRegexSimple + timesTakenWithSimpleDateFormatParse (in nanoseconds):" + (double) (sumOfTimes[2] + sumOfTimes[4]) / timesSize);
            System.out.println("AVG from timesTakenWithDateRegexSimpleOnlyWholeString + timesTakenWithSimpleDateFormatParse (in nanoseconds):" + (double) (sumOfTimes[3] + sumOfTimes[4]) / timesSize);
            System.out.println("AVG from timesTakenWithdateValidatorSimple (in nanoseconds):" + (double) sumOfTimes[5] / timesSize);
            System.out.println("AVG from timesTakenWithdateValidatorSimpleOnlyWholeString (in nanoseconds):" + (double) sumOfTimes[6] / timesSize);
        }
    }

    static class DateChecker {

        private Matcher matcher;
        private Pattern pattern;

        public DateChecker(String regex) {
            pattern = Pattern.compile(regex);
        }

        /**
         * Checks if the date format is a valid.
         * Uses the regex pattern to match the date first. 
         * Than additionally checks are performed on the boundaries of the days taken the month into account (leap years are covered).
         * 
         * @param date the date that needs to be checked.
         * @return if the date is of an valid format or not.
         */
        public boolean check(final String date) {
            matcher = pattern.matcher(date);
            if (matcher.matches()) {
                matcher.reset();
                if (matcher.find()) {
                    int day = Integer.parseInt(matcher.group(1));
                    int month = Integer.parseInt(matcher.group(2));
                    int year = Integer.parseInt(matcher.group(3));

                    switch (month) {
                    case 1:
                    case 3:
                    case 5:
                    case 7:
                    case 8:
                    case 10:
                    case 12: return day < 32;
                    case 4:
                    case 6:
                    case 9:
                    case 11: return day < 31;
                    case 2: 
                        int modulo100 = year % 100;
                        //http://science.howstuffworks.com/science-vs-myth/everyday-myths/question50.htm
                        if ((modulo100 == 0 && year % 400 == 0) || (modulo100 != 0 && year % LEAP_STEP == 0)) {
                            //its a leap year
                            return day < 30;
                        } else {
                            return day < 29;
                        }
                    default:
                        break;
                    }
                }
            }
            return false;
        }

        public String getRegex() {
            return pattern.pattern();
        }
    }
}

便利なメモ:
-アサーション(アサートチェック)を有効にするには、テスターの実行時に-ea引数を使用する必要があります。 (Eclipseでは、実行/デバッグ構成->引数タブ-> VM引数-> "-ea"を挿入して編集します。
-上記の正規表現は1800〜2199年に制限されています
-日付文字列全体とのみ一致させるために、先頭に^を、末尾に$を使用する必要はありません。 String.matchesがそれを処理します。
-有効なケースと無効なケースを確認し、ルールに従って変更してください。
-各正規表現の「文字列全体のみ」バージョンは、「通常」バージョン(^および$のないバージョン)と同じ速度を提供します。パフォーマンスの違いが見られる場合、これはJavaが同じ命令の処理に「慣れる」ため、時間が短縮されるためです。 「通常」バージョンと「文字列全体のみ」バージョンが実行される行を切り替えると、これが証明されていることがわかります。

これが誰かを助けることを願っています!
乾杯、
デポ

9
despot

Java.time

Java 8+を使用して日付/時刻の検証を行う適切な(そして簡単な)方法は、 Java.time.format.DateTimeFormatter クラスを使用することです。検証に正規表現を使用することは、日付にはあまり理想的ではありません。この質問の例の場合:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

try {
    LocalDate date = formatter.parse(text, LocalDate::from);
} catch (DateTimeParseException e) {
    // Thrown if text could not be parsed in the specified format
}

このコードは、テキストを解析し、有効な日付であることを検証し、日付を LocalDate オブジェクトとして返します。 DateTimeFormatterクラスには、ユースケースがそれらのいずれかに一致する場合、ISO標準に一致する静的な定義済みの日付形式がいくつかあることに注意してください。

4
Mike

マスクを使用してSimpleDateFormatを作成し、次に呼び出します:SimpleDateFormat.parse(String s、ParsePosition p)

2
Keilly

細かく制御するには、Steve Bが提案するSimpleDateFormat("YYYY-MM-dd")を使用して InputVerifier を検討してください。

1
trashgod

単純な正規表現が必要な場合は、正確ではありません。 https://www.freeformatter.com/Java-regex-tester.html#ad-output は、Java正規表現をテストするツールを提供します。また、下部には、日付を検証するためのいくつかの推奨正規表現があります。

ISO日付形式(yyyy-mm-dd):

^[0-9]{4}-(((0[13578]|(10|12))-(0[1-9]|[1-2][0-9]|3[0-1]))|(02-(0[1-9]|[1-2][0-9]))|((0[469]|11)-(0[1-9]|[1-2][0-9]|30)))$

ISO日付形式(yyyy-mm-dd)、区切り文字「-」または「/」または「。」または ' '。日付全体で同じセパレーターを強制的に使用します。

^[0-9]{4}([- /.])(((0[13578]|(10|12))\1(0[1-9]|[1-2][0-9]|3[0-1]))|(02\1(0[1-9]|[1-2][0-9]))|((0[469]|11)\1(0[1-9]|[1-2][0-9]|30)))$

米国の日付形式(mm/dd/yyyy)

^(((0[13578]|(10|12))/(0[1-9]|[1-2][0-9]|3[0-1]))|(02/(0[1-9]|[1-2][0-9]))|((0[469]|11)/(0[1-9]|[1-2][0-9]|30)))/[0-9]{4}$

時間と分、24時間形式(HH:MM):

^(20|21|22|23|[01]\d|\d)((:[0-5]\d){1,2})$

幸運を

0
Ali

パターンdd-MM-yyyyを使用している場合、以下の追加コードが機能します。

public boolean isValidDate(String date) {
        boolean check;
        String date1 = "^(0?[1-9]|[12][0-9]|3[01])-(0?[1-9]|1[012])-([12][0-9]{3})$";
        check = date.matches(date1);

        return check;
    }
0
JoboFive

次の正規表現は、うるう年を考慮してYYYY-MM-DD(1600-2999年の範囲内)形式の日付を受け入れます。

 ^((?:(?:1[6-9]|2[0-9])\d{2})(-)(?:(?:(?:0[13578]|1[02])(-)31)|((0[1,3-9]|1[0-2])(-)(29|30))))$|^(?:(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00)))(-)02(-)29)$|^(?:(?:1[6-9]|2[0-9])\d{2})(-)(?:(?:0[1-9])|(?:1[0-2]))(-)(?:0[1-9]|1\d|2[0-8])$

例:

Date regex examples

テストできます here

注:1桁を月または日として受け入れる場合は、次を使用できます。

 ^((?:(?:1[6-9]|2[0-9])\d{2})(-)(?:(?:(?:0?[13578]|1[02])(-)31)|((0?[1,3-9]|1[0-2])(-)(29|30))))$|^(?:(?:(?:(?:1[6-9]|[2-9]\d)?(?:0[48]|[2468][048]|[13579][26])|(?:(?:16|[2468][048]|[3579][26])00)))(-)0?2(-)29)$|^(?:(?:1[6-9]|2[0-9])\d{2})(-)(?:(?:0?[1-9])|(?:1[0-2]))(-)(?:0?[1-9]|1\d|2[0-8])$

これから始まる上記の正規表現を作成しました solution

0
Yahya Hussein