- * Cron expressions are comprised of 6 required fields and one optional field - * separated by white space. The fields respectively are described as follows: + * Cron 表达式由 6 个必填字段和 1 个可选字段组成，字段之间通过空格分隔。各字段的详细说明如下： * *
| Field Name | + *字段名称 | *- * | Allowed Values | + *允许值 | *- * | Allowed Special Characters | + *允许的特殊字符 | *
|---|---|---|---|---|---|---|---|
Seconds |
+ * 秒（Seconds） |
* * | 0-59 |
* * | , - * / |
* ||
Minutes |
+ * 分（Minutes） |
* * | 0-59 |
* * | , - * / |
* ||
Hours |
+ * 时（Hours） |
* * | 0-23 |
* * | , - * / |
* ||
Day-of-month |
+ * 日（Day-of-month） |
* * | 1-31 |
* * | , - * ? / L W |
* ||
Month |
+ * 月（Month） |
* - * | 0-11 or JAN-DEC |
+ * 0-11 或 JAN-DEC（一月至十二月） |
* * | , - * / |
* |
Day-of-Week |
+ * 周（Day-of-Week） |
* - * | 1-7 or SUN-SAT |
+ * 1-7 或 SUN-SAT（周日至周六） |
* * | , - * ? / L # |
* |
Year (Optional) |
+ * 年（Year，可选） |
* - * | empty, 1970-2199 |
+ * 空值、1970-2199 |
* * | , - * / |
*
- * The '*' character is used to specify all values. For example, "*" - * in the minute field means "every minute". + * '*' 字符用于指定“所有可能的值”。例如，在“分钟”字段中使用 "*" 表示“每分钟”。 *
- * The '?' character is allowed for the day-of-month and day-of-week fields. It - * is used to specify 'no specific value'. This is useful when you need to - * specify something in one of the two fields, but not the other. + * '?' 字符仅允许在“日（Day-of-month）”和“周（Day-of-Week）”字段中使用， + * 用于表示“不指定具体值”。当你需要在这两个字段中的一个指定条件，而另一个无需指定时，该字符非常有用。 *
- * The '-' character is used to specify ranges For example "10-12" in - * the hour field means "the hours 10, 11 and 12". + * '-' 字符用于指定时间范围。例如，在“小时”字段中使用 "10-12" 表示“上午 10 点、11 点和中午 12 点”。 *
- * The ',' character is used to specify additional values. For example - * "MON,WED,FRI" in the day-of-week field means "the days Monday, - * Wednesday, and Friday". + * ',' 字符用于指定多个额外的取值。例如，在“周”字段中使用 "MON,WED,FRI" 表示“周一、周三和周五”。 *
- * The '/' character is used to specify increments. For example "0/15" - * in the seconds field means "the seconds 0, 15, 30, and 45". And - * "5/15" in the seconds field means "the seconds 5, 20, 35, and - * 50". Specifying '*' before the '/' is equivalent to specifying 0 is - * the value to start with. Essentially, for each field in the expression, there - * is a set of numbers that can be turned on or off. For seconds and minutes, - * the numbers range from 0 to 59. For hours 0 to 23, for days of the month 0 to - * 31, and for months 0 to 11 (JAN to DEC). The "/" character simply helps you turn - * on every "nth" value in the given set. Thus "7/6" in the - * month field only turns on month "7", it does NOT mean every 6th - * month, please note that subtlety. + * '/' 字符用于指定递增步长。例如，在“秒”字段中使用 "0/15" 表示“第 0 秒、15 秒、30 秒和 45 秒”； + * 而 "5/15" 在“秒”字段中表示“第 5 秒、20 秒、35 秒和 50 秒”。在 '/' 前指定 '*' 等价于以 0 作为起始值。 + * 本质上，表达式的每个字段都对应一组可启用或禁用的数字集合：秒和分的范围是 0-59，小时是 0-23， + * 日是 1-31，月是 0-11（对应 JAN 至 DEC）。'/' 字符的作用是在指定集合中启用“每隔 n 个”的取值。 + * 需要注意一个细节：在“月”字段中使用 "7/6" 仅会启用“7 月”，并不表示“每 6 个月”。 *
- * The 'L' character is allowed for the day-of-month and day-of-week fields. - * This character is short-hand for "last", but it has different - * meaning in each of the two fields. For example, the value "L" in - * the day-of-month field means "the last day of the month" - day 31 - * for January, day 28 for February on non-leap years. If used in the - * day-of-week field by itself, it simply means "7" or - * "SAT". But if used in the day-of-week field after another value, it - * means "the last xxx day of the month" - for example "6L" - * means "the last friday of the month". You can also specify an offset - * from the last day of the month, such as "L-3" which would mean the third-to-last - * day of the calendar month. When using the 'L' option, it is important not to - * specify lists, or ranges of values, as you'll get confusing/unexpected results. + * 'L' 字符仅允许在“日（Day-of-month）”和“周（Day-of-Week）”字段中使用，是“last（最后一个）”的缩写， + * 但在两个字段中的含义有所不同。例如，在“日”字段中使用 "L" 表示“当月的最后一天”——1 月对应 31 日， + * 非闰年的 2 月对应 28 日。若在“周”字段中单独使用 "L"，仅表示“7”或“SAT（周六）”； + * 若在其他值后使用，则表示“当月最后一个指定星期几”，例如 "6L" 表示“当月最后一个周五”。 + * 你也可以指定相对于月末的偏移量，例如 "L-3" 表示“当月的倒数第三天”。 + * 注意：使用 'L' 选项时，请勿同时指定多个取值（列表）或范围，否则会得到混乱或不符合预期的结果。 *
- * The 'W' character is allowed for the day-of-month field. This character - * is used to specify the weekday (Monday-Friday) nearest the given day. As an - * example, if you were to specify "15W" as the value for the - * day-of-month field, the meaning is: "the nearest weekday to the 15th of - * the month". So if the 15th is a Saturday, the trigger will fire on - * Friday the 14th. If the 15th is a Sunday, the trigger will fire on Monday the - * 16th. If the 15th is a Tuesday, then it will fire on Tuesday the 15th. - * However if you specify "1W" as the value for day-of-month, and the - * 1st is a Saturday, the trigger will fire on Monday the 3rd, as it will not - * 'jump' over the boundary of a month's days. The 'W' character can only be - * specified when the day-of-month is a single day, not a range or list of days. + * 'W' 字符仅允许在“日（Day-of-month）”字段中使用，用于指定“距离给定日期最近的工作日（周一至周五）”。 + * 例如，若在“日”字段中指定 "15W"，含义是“当月 15 日附近最近的工作日”：如果 15 日是周六， + * 则触发时间为 14 日（周五）；如果 15 日是周日，则触发时间为 16 日（周一）；如果 15 日是周二， + * 则触发时间为 15 日（周二）本身。若指定 "1W" 且 1 日是周六，触发时间会是 3 日（周一）， + * 因为该字符不会“跨越”月份的边界。'W' 字符仅能在“日”字段指定单个日期时使用， + * 不能用于日期范围或多个日期列表。 *
- * The 'L' and 'W' characters can also be combined for the day-of-month - * expression to yield 'LW', which translates to "last weekday of the - * month". + * 'L' 和 'W' 字符可在“日（Day-of-month）”字段中组合使用，形成 "LW"，含义是“当月的最后一个工作日”。 *
- * The '#' character is allowed for the day-of-week field. This character is - * used to specify "the nth" XXX day of the month. For example, the - * value of "6#3" in the day-of-week field means the third Friday of - * the month (day 6 = Friday and "#3" = the 3rd one in the month). - * Other examples: "2#1" = the first Monday of the month and - * "4#5" = the fifth Wednesday of the month. Note that if you specify - * "#5" and there is not 5 of the given day-of-week in the month, then - * no firing will occur that month. If the '#' character is used, there can - * only be one expression in the day-of-week field ("3#1,6#3" is - * not valid, since there are two expressions). + * '#' 字符仅允许在“周（Day-of-Week）”字段中使用，用于指定“当月第 n 个星期几”。 + * 例如，在“周”字段中使用 "6#3" 表示“当月第三个周五”（6 对应周五，"#3" 对应第三个）。 + * 其他示例："2#1" 表示“当月第一个周一”，"4#5" 表示“当月第五个周三”。 + * 注意：若指定了 "#5" 但当月不存在对应的第 5 个星期几，则该月不会触发任务。 + * 此外，使用 '#' 字符时，“周”字段中只能包含一个表达式（例如 "3#1,6#3" 是无效的，因为它包含两个表达式）。 *
- * + * *
- * The legal characters and the names of months and days of the week are not - * case sensitive. + * 所有合法字符以及月份、星期几的名称均不区分大小写。 * *
- * NOTES: + * 注意事项： *
- * Borrowed from quartz v2.3.1 + * 源自 Quartz 框架 v2.3.1 版本 */ public final class CronExpression { @@ -1160,13 +1119,6 @@ public final class CronExpression { return integer; } - //////////////////////////////////////////////////////////////////////////// - // - // Computation Functions - // - - /// ///////////////////////////////////////////////////////////////////////// - public Date getTimeAfter(Date afterTime) { // Computation is based on Gregorian year only.