检查月份或日期或年份是否在字符串格式的两个日期范围内

Check if month or day or year is in range of two dates in string format

但现在我意识到我可以有更多案例来解决这个问题。

我有一个过滤器,它是一个字符串,只能接受 3 种日期格式 - YYYYYYYY-MMYYYY-MM-DD

我想检查请求的字符串是否在两个字符串值日期的范围内。

比方说,我有两个日期字符串,可以是上述 3 种日期格式中的任何一种


用例 1

开始日期:2010-05-15 & 结束日期:2020-05

以下所有requested String 都在结果范围内:

201020202010-052020-052020-05-222010-05-152010-05-222015-02-25

下面的所有 requested String

范围内

2009, 2021, 2010-04, 2020-06, 2010-05-14, 2020-06-01


用例 2

开始日期:2010 & 结束日期:2020-05-15

以下所有值都在结果范围内:

201020202010-052020-052010-05-222010-01-012020-05-152015-02-25

以下所有值

范围内

200920212020-062020-05-162020-06-01


用例 3

开始日期:NULL & 结束日期:2020-05

2020-05-31 之前的所有请求日期都在结果范围内:

2020-05-31 之后的所有值都不在范围内。


用例 4

开始日期:2010-05-15 & 结束日期:NULL

2010-05-15 之后 的所有请求日期都在结果范围内:

2010-05-15 之前的所有值都不在范围内。


我正在使用 Java 时间来检查日期是在给定日期之前还是之后,但在我的例子中,我有一个字符串作为请求日期、开始日期和结束日期,它可能是采用 3 种日期格式中的任何一种。

我不确定这是否是一个有效的解决方案,但这就是我的想法

只需将所有日期(请求日期、开始日期和结束日期)分解为数字并将请求年份与开始和结束年份进行比较,如果请求日期中的月份可用且开始和结束日期也可用,则比较是否月份在范围内,日期也一样。

有人可以帮忙解决这个问题吗?

    Date min, max;   // assume these are set to something
    Date d;          // the date in question

   return d.after(min) && d.before(max);

将所有字符串输入转换为 LocalDate 个对象

别再用字符串思考了。这些字符串仅用于用户界面和将值序列化到存储。当您的应用程序是 运行 时,您应该使用对象执行您的逻辑,java.time 个对象,最终 LocalDate

将所有输入转换为 LocalDate

检查输入的长度。

if( input.length() = 4 ) {…}

如果输入长度为4个字符,则解析为Year. Trap for exception thrown in case faulty input gets past your filter. From the year, get a LocalDate by calling atDay

try{
    Year year = Year.parse( "2020" ) ; 
     LocalDate ld = year.atDay( 1 ) ;
} catch ( DateTimeParseException e ) {
    …
}

如果输入是七个字符,则解析为 YearMonth。通过 atDay 方法获得 LocalDate 的表单。

try{
    YearMonth YearMonth = YearMonth.parse( "2020-05" ) ; 
     LocalDate ld = yearMonth.atDay( 1 ) ;
} catch ( DateTimeParseException e ) {
    …
}

如果输入是 10 个字符,则解析为 LocalDate

try{
    LocalDate localDate = LocalDate.parse( "2020-05-23" ) ; 
} catch ( DateTimeParseException e ) {
    …
}

所有 LocalDate 对象就位后,进行比较。在定义时间跨度时始终使用半开放方法。开头包含,结尾不包含

提示:“不早于”是询问“等于或晚于”的简写方式。

( ! target.isBefore( start ) ) && target.isBefore( stop ) 

由于您的日期采用 yyyy-MM-dd 格式,您应该能够执行字符串比较,确保只比较相同长度的字符串(注意比较不同日期的规则长度):

private static boolean isDateInRange(String startDate, String endDate, String date) {
    return (null == startDate || compareDateString(startDate, date) <= 0)
            && (null == endDate || compareDateString(date, endDate) <= 0);
}

private static int compareDateString(String date1, String date2) {
    if (date1.length() == date2.length())
        return date1.compareTo(date2);

    int length = Math.min(date1.length(), date2.length());
    return date1.substring(0, length).compareTo(date2.substring(0, length));
}

您可以通过以下方式查看:

String startDate = "2010-05-15";
String endDate = "2020-05";
String date = "2020-06";

boolean inRange = isDateInRange(startDate, endDate, date);

简洁明了,因此您应该使用它,但它之所以有效,是因为日期格式是简单的 ISO-8601 文本。如果格式不同,您需要先解析它们,然后才能比较它们。这里有一个解析字符串的方案,当然逻辑会比较复杂。

我将从创建一个助手开始 class:

/**
 * Class for storing a {@code Temporal} of varying precision,
 * {@code Year}, {@code YearMonth}, or {@code LocalDate}.
 */
class DynamicTemporal {

    private enum Precision {
        YEAR {
            @Override
            protected int compare(Temporal a, Temporal b) {
                return widen(a).compareTo(widen(b));
            }
            private Year widen(Temporal value) {
                return Year.from(value);
            }
        },
        MONTH {
            @Override
            protected int compare(Temporal a, Temporal b) {
                return widen(a).compareTo(widen(b));
            }
            private YearMonth widen(Temporal value) {
                return YearMonth.from(value);
            }
        },
        DAY {
            @Override
            protected int compare(Temporal a, Temporal b) {
                return widen(a).compareTo(widen(b));
            }
            private LocalDate widen(Temporal value) {
                return (LocalDate) value;
            }
        };
        protected abstract int compare(Temporal a, Temporal b);
    }

    private final Temporal value;
    private final Precision precision;

    public static DynamicTemporal parse(String text) {
        if (text == null || text.equals("NULL"))
            return null;
        if (text.length() >= 10)
            return new DynamicTemporal(LocalDate.parse(text), Precision.DAY);
        if (text.length() >= 7)
            return new DynamicTemporal(YearMonth.parse(text), Precision.MONTH);
        return new DynamicTemporal(Year.parse(text), Precision.YEAR);
    }

    private DynamicTemporal(Temporal value, Precision precision) {
        this.value = value;
        this.precision = precision;
    }

    public int compareTo(DynamicTemporal other) {
        Precision effectivePrecision = (this.precision.compareTo(other.precision) <= 0 ? this.precision : other.precision);
        return effectivePrecision.compare(this.value, other.value);
    }
}

现在您可以轻松实现isDateInRange()方法:

private static boolean isDateInRange(String start, String end, String date) {
    DynamicTemporal dateTemporal = DynamicTemporal.parse(date);
    DynamicTemporal startTemporal = DynamicTemporal.parse(start);
    DynamicTemporal endTemporal = DynamicTemporal.parse(end);
    if (startTemporal != null && dateTemporal.compareTo(startTemporal) < 0)
        return false; // date is before start
    if (endTemporal != null && dateTemporal.compareTo(endTemporal) > 0)
        return false; // date is after end
    return true;
}

测试(来自问题)

public static void main(String[] args) {
    test("2010-05-15", "2020-05", true, "2010", "2020", "2010-05", "2020-05", "2020-05-22", "2010-05-15", "2010-05-22", "2015-02-25");
    test("2010-05-15", "2020-05", false, "2009", "2021", "2010-04", "2020-06", "2010-05-14", "2020-06-01");

    test("2010", "2020-05-15", true, "2010", "2020", "2010-05", "2020-05", "2010-05-22", "2010-01-01", "2020-05-15", "2015-02-25");
    test("2010", "2020-05-15", false, "2009", "2021", "2020-06", "2020-05-16", "2020-06-01");

    test("NULL", "2020-05", true, "2020-05-31", "2020-05", "2020", "2020-05-30", "2020-04", "2019");
    test("NULL", "2020-05", false, "2020-06-01", "2020-06", "2021", "2020-06-02", "2020-07", "2022");

    test("2010-05-15", "NULL", true, "2010-05-15", "2010-05", "2010", "2010-05-16", "2010-06", "2011");
    test("2010-05-15", "NULL", false, "2010-05-14", "2010-04", "2009", "2010-05-13", "2010-03", "2008");
}
private static void test(String start, String end, boolean expected, String... dates) {
    for (String date : dates) {
        boolean actual = isDateInRange(start, end, date);
        System.out.printf("isDateInRange(%-10s, %-10s, %-10s) = %-5s   %s%n",
                          start, end, date, actual, (actual == expected ? "OK" : "FAILED!"));
    }
}

输出

isDateInRange(2010-05-15, 2020-05   , 2010      ) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2020      ) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2010-05   ) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2020-05   ) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2020-05-22) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2010-05-15) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2010-05-22) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2015-02-25) = true    OK
isDateInRange(2010-05-15, 2020-05   , 2009      ) = false   OK
isDateInRange(2010-05-15, 2020-05   , 2021      ) = false   OK
isDateInRange(2010-05-15, 2020-05   , 2010-04   ) = false   OK
isDateInRange(2010-05-15, 2020-05   , 2020-06   ) = false   OK
isDateInRange(2010-05-15, 2020-05   , 2010-05-14) = false   OK
isDateInRange(2010-05-15, 2020-05   , 2020-06-01) = false   OK
isDateInRange(2010      , 2020-05-15, 2010      ) = true    OK
isDateInRange(2010      , 2020-05-15, 2020      ) = true    OK
isDateInRange(2010      , 2020-05-15, 2010-05   ) = true    OK
isDateInRange(2010      , 2020-05-15, 2020-05   ) = true    OK
isDateInRange(2010      , 2020-05-15, 2010-05-22) = true    OK
isDateInRange(2010      , 2020-05-15, 2010-01-01) = true    OK
isDateInRange(2010      , 2020-05-15, 2020-05-15) = true    OK
isDateInRange(2010      , 2020-05-15, 2015-02-25) = true    OK
isDateInRange(2010      , 2020-05-15, 2009      ) = false   OK
isDateInRange(2010      , 2020-05-15, 2021      ) = false   OK
isDateInRange(2010      , 2020-05-15, 2020-06   ) = false   OK
isDateInRange(2010      , 2020-05-15, 2020-05-16) = false   OK
isDateInRange(2010      , 2020-05-15, 2020-06-01) = false   OK
isDateInRange(NULL      , 2020-05   , 2020-05-31) = true    OK
isDateInRange(NULL      , 2020-05   , 2020-05   ) = true    OK
isDateInRange(NULL      , 2020-05   , 2020      ) = true    OK
isDateInRange(NULL      , 2020-05   , 2020-05-30) = true    OK
isDateInRange(NULL      , 2020-05   , 2020-04   ) = true    OK
isDateInRange(NULL      , 2020-05   , 2019      ) = true    OK
isDateInRange(NULL      , 2020-05   , 2020-06-01) = false   OK
isDateInRange(NULL      , 2020-05   , 2020-06   ) = false   OK
isDateInRange(NULL      , 2020-05   , 2021      ) = false   OK
isDateInRange(NULL      , 2020-05   , 2020-06-02) = false   OK
isDateInRange(NULL      , 2020-05   , 2020-07   ) = false   OK
isDateInRange(NULL      , 2020-05   , 2022      ) = false   OK
isDateInRange(2010-05-15, NULL      , 2010-05-15) = true    OK
isDateInRange(2010-05-15, NULL      , 2010-05   ) = true    OK
isDateInRange(2010-05-15, NULL      , 2010      ) = true    OK
isDateInRange(2010-05-15, NULL      , 2010-05-16) = true    OK
isDateInRange(2010-05-15, NULL      , 2010-06   ) = true    OK
isDateInRange(2010-05-15, NULL      , 2011      ) = true    OK
isDateInRange(2010-05-15, NULL      , 2010-05-14) = false   OK
isDateInRange(2010-05-15, NULL      , 2010-04   ) = false   OK
isDateInRange(2010-05-15, NULL      , 2009      ) = false   OK
isDateInRange(2010-05-15, NULL      , 2010-05-13) = false   OK
isDateInRange(2010-05-15, NULL      , 2010-03   ) = false   OK
isDateInRange(2010-05-15, NULL      , 2008      ) = false   OK

将所有内容转换为日期范围。将日期范围表示为从开始日期到结束日期不包括 的半开间隔。并将开始日期和结束日期表示为两个 LocalDate 对象。

例如,从您的用例 1

Start date: 2010-05-15 & end date: 2020-05

作为日期范围,这变为 从 2010-05-15(含)到 2020-06-01(不含)

要测试 2010 是否在范围内,请将 2010 转换为 从 2010-01-01 到 2011-01-01 exclusive 的范围。现在,当且仅当这两个范围重叠时,2010 年才在范围内。当且仅当第一个起始日期早于第二个日期 第二个起始日期早于第一个日期时,他们才会这样做。使用 LocalDate.isBefore()。我们需要“strict before”,而这个方法正好给了我们这个。由于 2010-05-15 在 2011-01-01 之前 2010-01-01 在 2020-06-01 之前,范围重叠,因此我们得出结论 2010 在范围内.

案例1的另一个例子,为了测试2010-05-14是否在同一范围内,将其转换为范围从2010-05-14到2010-05-15(不包括) 。查看 2010-05-15 是否早于 2010-05-15 2010-05-14 是否早于 2020-06-01。前半部分已经是假的,所以我们断定日期不在范围内。

实施说明:我可能会使用此格式化程序来解析您的所有字符串:

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("uuuu[-MM[-dd]]");

您可以使用此格式化程序的 parseBest 方法从您提到的任何字符串中获取 LocalDateYearMonthYear。在每种情况下,您都可以从那里转换。

Link: Determine Whether Two Date Ranges Overlap

I am not sure if this is a valid solution but this is what I am thinking

Simply break all the dates (requested, start, & end) into numbers and compare requested year with years in start & end, if months in requested date is available and also available in the start and end then compare if the month is in range, and same for the dates.

是的,你的方法是有效的。 java.time 中的 类 没有提供完美的支持,但是使用低级 TemporalAccessor 接口有一个方法:

class IsInRangeWithMissingFields {

    @Test
    void useCase1() {
        assertTrue(isInRange("2010-05-15", "2020-05", "2010"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2020"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2010-05"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2020-05"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2020-05-22"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2010-05-15"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2010-05-22"));
        assertTrue(isInRange("2010-05-15", "2020-05", "2015-02-25"));
        assertFalse(isInRange("2010-05-15", "2020-05", "2009"));
        assertFalse(isInRange("2010-05-15", "2020-05", "2021"));
        assertFalse(isInRange("2010-05-15", "2020-05", "2010-04"));
        assertFalse(isInRange("2010-05-15", "2020-05", "2020-06"));
        assertFalse(isInRange("2010-05-15", "2020-05", "2010-05-14"));
        assertFalse(isInRange("2010-05-15", "2020-05", "2020-06-01"));
    }

    @Test
    void useCase2() {
        assertTrue(isInRange("2010", "2020-05-15", "2010"));
        assertTrue(isInRange("2010", "2020-05-15", "2020"));
        assertTrue(isInRange("2010", "2020-05-15", "2010-05"));
        assertTrue(isInRange("2010", "2020-05-15", "2020-05"));
        assertTrue(isInRange("2010", "2020-05-15", "2010-05-22"));
        assertTrue(isInRange("2010", "2020-05-15", "2010-01-01"));
        assertTrue(isInRange("2010", "2020-05-15", "2020-05-15"));
        assertTrue(isInRange("2010", "2020-05-15", "2015-02-25"));
        assertFalse(isInRange("2010", "2020-05-15", "2009"));
        assertFalse(isInRange("2010", "2020-05-15", "2021"));
        assertFalse(isInRange("2010", "2020-05-15", "2020-06"));
        assertFalse(isInRange("2010", "2020-05-15", "2020-05-16"));
        assertFalse(isInRange("2010", "2020-05-15", "2020-06-01"));
    }

    @Test
    void useCase3() {
        assertTrue(isInRange(null, "2020-05", "2020-05-31"));
        assertFalse(isInRange(null, "2020-05", "2020-06-01"));
    }

    @Test
    void useCase4() {
        assertTrue(isInRange("2010-05-15", null, "2010-05-15"));
        assertFalse(isInRange("2010-05-15", null, "2010-05-14"));
    }

    private static DateTimeFormatter formatter = DateTimeFormatter.ofPattern("uuuu[-MM[-dd]]");

    public static boolean isInRange(String startStr, String endStr, String requestStr) {
        TemporalAccessor request = formatter.parse(requestStr);

        // is request before start?
        if (startStr != null) {
            TemporalAccessor start = formatter.parse(startStr);
            if (request.get(ChronoField.YEAR)
                    < start.get(ChronoField.YEAR)) {
                return false;
            }
            if (request.get(ChronoField.YEAR)
                    == start.get(ChronoField.YEAR)) {
                if (request.isSupported(ChronoField.MONTH_OF_YEAR)
                        && start.isSupported(ChronoField.MONTH_OF_YEAR)) {
                    if (request.get(ChronoField.MONTH_OF_YEAR)
                            < start.get(ChronoField.MONTH_OF_YEAR)) {
                        return false;
                    }
                    if (request.get(ChronoField.MONTH_OF_YEAR)
                            == start.get(ChronoField.MONTH_OF_YEAR)) {
                        if (request.isSupported(ChronoField.DAY_OF_MONTH)
                                && start.isSupported(ChronoField.DAY_OF_MONTH)) {
                            if (request.get(ChronoField.DAY_OF_MONTH)
                                    < start.get(ChronoField.DAY_OF_MONTH)) {
                                return false;
                            }
                        }
                    }
                }
            }
        }

        // is request after end?
        if (endStr != null) {
            TemporalAccessor end = formatter.parse(endStr);
            if (request.get(ChronoField.YEAR) > end.get(ChronoField.YEAR)) {
                return false;
            }
            if (request.get(ChronoField.YEAR) == end.get(ChronoField.YEAR)) {
                if (request.isSupported(ChronoField.MONTH_OF_YEAR)
                        && end.isSupported(ChronoField.MONTH_OF_YEAR)) {
                    if (request.get(ChronoField.MONTH_OF_YEAR)
                            > end.get(ChronoField.MONTH_OF_YEAR)) {
                        return false;
                    }
                    if (request.get(ChronoField.MONTH_OF_YEAR)
                            == end.get(ChronoField.MONTH_OF_YEAR)) {
                        if (request.isSupported(ChronoField.DAY_OF_MONTH)
                                && end.isSupported(ChronoField.DAY_OF_MONTH)) {
                            if (request.get(ChronoField.DAY_OF_MONTH)
                                    > end.get(ChronoField.DAY_OF_MONTH)) {
                                return false;
                            }
                        }
                    }
                }
            }
        }

        return true;
    }

}

此单元测试在我的计算机上运行时出现绿色障碍。