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Separated out all regex groups so that they are visible literals, mak…
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…ing the regex's easier to read.
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@jdereg
jdereg committed Jan 23, 2024
1 parent 278099d commit 80dc959
Showing 1 changed file with 24 additions and 28 deletions.
52 changes: 24 additions & 28 deletions src/main/java/com/cedarsoftware/util/DateUtilities.java
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/**
* Utility for parsing String dates with optional times, especially when the input String formats
* may be inconsistent. This will parse the following formats (constrained only by java.util.Date limitations...best
* time resolution is milliseconds):<br/>
* may be inconsistent. This will parse the following formats:<br/>
* <pre>
* 12-31-2023, 12/31/2023, 12.31.2023 mm is 1-12 or 01-12, dd is 1-31 or 01-31, and yyyy can be 0000 to 9999.
*
* 2023-12-31, 2023/12/31, 2023.12.31 mm is 1-12 or 01-12, dd is 1-31 or 01-31, and yyyy can be 0000 to 9999.
*
* January 6th, 2024 Month (3-4 digit abbreviation or full English name), white-space and optional comma,
* day of month (1-31 or 0-31) with optional suffixes 1st, 3rd, 22nd, whitespace and
* day of month (1-31) with optional suffixes 1st, 3rd, 22nd, whitespace and
* optional comma, and yyyy (0000-9999)
*
* 17th January 2024 day of month (1-31 or 0-31) with optional suffixes (e.g. 1st, 3rd, 22nd),
* 17th January 2024 day of month (1-31) with optional suffixes (e.g. 1st, 3rd, 22nd),
* Month (3-4 digit abbreviation or full English name), whites space and optional comma,
* and yyyy (0000-9999)
*
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*
* hh:mm:ss hours (00-23), minutes (00-59), seconds (00-59). 24 hour format.
*
* hh:mm:ss.sssss hh:mm:ss and fractional seconds. Variable fractional seconds supported. Date only
* supports up to millisecond precision, so anything after 3 decimal places is ignored.
* hh:mm:ss.sssss hh:mm:ss and fractional seconds. Variable fractional seconds supported.
*
* hh:mm:offset -or- offset can be specified as +HH:mm, +HHmm, +HH, -HH:mm, -HHmm, -HH, or Z (GMT)
* hh:mm:ss.sss:offset which will match: "12:34", "12:34:56", "12:34.789", "12:34:56.789", "12:34+01:00",
* "12:34:56+1:00", "12:34-01", "12:34:56-1", "12:34Z", "12:34:56Z"
*
* hh:mm:zone -or- Zone can be specified as Z (Zulu = UTC), older short forms: GMT, EST, CST, MST,
* hh:mm:ss.sss:zone PST, IST, JST, BST etc. as well as the long forms: "America/New York", "Asia/Saigon",
* hh:mm:ss.sss:zone PST, IST, JST, BST etc. as well as the long forms: "America/New_York", "Asia/Saigon",
* etc. See ZoneId.getAvailableZoneIds().
* </pre>
* DateUtilities will parse Epoch-based integer-based value. It is considered number of milliseconds since Jan, 1970 GMT.
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*/
public final class DateUtilities {
private static final Pattern allDigits = Pattern.compile("^\\d+$");
private static final String days = "\\b(monday|mon|tuesday|tues|tue|wednesday|wed|thursday|thur|thu|friday|fri|saturday|sat|sunday|sun)\\b"; // longer before shorter matters
private static final String mos = "\\b(January|Jan|February|Feb|March|Mar|April|Apr|May|June|Jun|July|Jul|August|Aug|September|Sept|Sep|October|Oct|November|Nov|December|Dec)\\b";
private static final String yr = "(\\d{4})";
private static final String dig1or2 = "\\d{1,2}";
private static final String dig1or2grp = "(" + dig1or2 + ")";
private static final String ord = dig1or2grp + "(st|nd|rd|th)?";
private static final String dig2 = "\\d{2}";
private static final String sep = "([./-])";
private static final String days = "monday|mon|tuesday|tues|tue|wednesday|wed|thursday|thur|thu|friday|fri|saturday|sat|sunday|sun"; // longer before shorter matters
private static final String mos = "January|Jan|February|Feb|March|Mar|April|Apr|May|June|Jun|July|Jul|August|Aug|September|Sept|Sep|October|Oct|November|Nov|December|Dec";
private static final String yr = "\\d{4}";
private static final String d1or2 = "\\d{1,2}";
private static final String d2 = "\\d{2}";
private static final String ord = "st|nd|rd|th";
private static final String sep = "[./-]";
private static final String ws = "\\s+";
private static final String wsOp = "\\s*";
private static final String wsOrComma = "[ ,]+";
private static final String tzUnix = "([A-Z]{1,3})?";
private static final String nano = "\\.\\d+";
private static final String dayOfMon = dig1or2grp;
private static final String tzUnix = "[A-Z]{1,3}";
private static final String tz_Hh_MM = "[+-]\\d{1,2}:\\d{2}";
private static final String tz_HHMM = "[+-]\\d{4}";
private static final String tz_Hh = "[+-]\\d{1,2}";
private static final String tzNamed = wsOp + "\\[?[A-Za-z][A-Za-z0-9~\\/._+-]+]?";
private static final String nano = "\\.\\d+";

// Patterns defined in BNF-style using above named elements
// Patterns defined in BNF influenced style using above named elements
private static final Pattern isoDatePattern = Pattern.compile( // Regex's using | (OR)
yr + sep + dig1or2grp + "\\2" + dig1or2grp + "|" + // 2024/01/21 (yyyy/mm/dd -or- yyyy-mm-dd -or- yyyy.mm.dd) [optional time, optional day of week] \2 references 1st separator (ensures both same)
dig1or2grp + sep + dig1or2grp + "\\6" + yr); // 01/21/2024 (mm/dd/yyyy -or- mm-dd-yyyy -or- mm.dd.yyyy) [optional time, optional day of week] \6 references 1st separator (ensures both same)
"(" + yr + ")(" + sep + ")(" + d1or2 + ")" + "\\2" + "(" + d1or2 + ")|" + // 2024/01/21 (yyyy/mm/dd -or- yyyy-mm-dd -or- yyyy.mm.dd) [optional time, optional day of week] \2 references 1st separator (ensures both same)
"(" + d1or2 + ")(" + sep + ")(" + d1or2 + ")" + "\\6(" + yr + ")"); // 01/21/2024 (mm/dd/yyyy -or- mm-dd-yyyy -or- mm.dd.yyyy) [optional time, optional day of week] \6 references 1st separator (ensures both same)

private static final Pattern alphaMonthPattern = Pattern.compile(
mos + wsOrComma + ord + wsOrComma + yr + "|" + // Jan 21st, 2024 (comma optional between all, day of week optional, time optional, ordinal text optional [st, nd, rd, th])
ord + wsOrComma + mos + wsOrComma + yr + "|" + // 21st Jan, 2024 (ditto)
yr + wsOrComma + mos + wsOrComma + ord, // 2024 Jan 21st (ditto)
"\\b(" + mos + ")\\b" + wsOrComma + "(" + d1or2 + ")(" + ord + ")?" + wsOrComma + "(" + yr + ")|" + // Jan 21st, 2024 (comma optional between all, day of week optional, time optional, ordinal text optional [st, nd, rd, th])
"(" + d1or2 + ")(" + ord + ")?" + wsOrComma + "\\b(" + mos + ")\\b" + wsOrComma + "(" + yr + ")|" + // 21st Jan, 2024 (ditto)
"(" + yr + ")" + wsOrComma + "\\b(" + mos + "\\b)" + wsOrComma + "(" + d1or2 + ")(" + ord + ")?", // 2024 Jan 21st (ditto)
Pattern.CASE_INSENSITIVE);

private static final Pattern unixDateTimePattern = Pattern.compile(
days + ws + mos + ws + dayOfMon + ws + "(" + dig2 + ":" + dig2 + ":" + dig2 + ")" + wsOp + tzUnix + wsOp + yr,
"\\b(" + days + ")\\b" + ws + "\\b(" + mos + ")\\b" + ws + "(" + d1or2 + ")" + ws + "(" + d2 + ":" + d2 + ":" + d2 + ")" + wsOp + "(" + tzUnix + ")?" + wsOp + "(" + yr + ")",
Pattern.CASE_INSENSITIVE);

private static final Pattern timePattern = Pattern.compile(
"(" + dig2 + "):(" + dig2 + "):?(" + dig2 + ")?(" + nano + ")?(" + tz_Hh_MM + "|" + tz_HHMM + "|" + tz_Hh + "|Z|" + tzNamed + ")?", // 5 groups
"(" + d2 + "):(" + d2 + "):?(" + d2 + ")?(" + nano + ")?(" + tz_Hh_MM + "|" + tz_HHMM + "|" + tz_Hh + "|Z|" + tzNamed + ")?",
Pattern.CASE_INSENSITIVE);

private static final Pattern dayPattern = Pattern.compile(days, Pattern.CASE_INSENSITIVE);
private static final Pattern dayPattern = Pattern.compile("\\b(" + days + ")\\b", Pattern.CASE_INSENSITIVE);
private static final Map<String, Integer> months = new ConcurrentHashMap<>();

static {
Expand Down Expand Up @@ -254,7 +250,7 @@ public static ZonedDateTime parseDate(String dateStr, ZoneId defaultZoneId, bool
sec = matcher.group(3);
}
if (matcher.group(4) != null) {
fracSec = "0." + matcher.group(4).substring(1);
fracSec = "0" + matcher.group(4);
}
if (matcher.group(5) != null) {
tz = stripBrackets(matcher.group(5).trim());
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