pig-master.zip

/* * All content copyright Terracotta, Inc., unless otherwise indicated. All rights reserved. * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy * of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. * */ package com.xxl.job.admin.core.cron; import java.io.Serializable; import java.text.ParseException; import java.util.*; /** * Provides a parser and evaluator for unix-like cron expressions. Cron expressions * provide the ability to specify complex time combinations such as &quot;At 8:00am every * Monday through Friday&quot; or &quot;At 1:30am every last Friday of the month&quot;. * <P> * Cron expressions are comprised of 6 required fields and one optional field separated by * white space. The fields respectively are described as follows: * * <table cellspacing="8"> * <tr> * <th align="left">Field Name</th> * <th align="left">&nbsp;</th> * <th align="left">Allowed Values</th> * <th align="left">&nbsp;</th> * <th align="left">Allowed Special Characters</th> * </tr> * <tr> * <td align="left"><code>Seconds</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>0-59</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * /</code></td> * </tr> * <tr> * <td align="left"><code>Minutes</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>0-59</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * /</code></td> * </tr> * <tr> * <td align="left"><code>Hours</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>0-23</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * /</code></td> * </tr> * <tr> * <td align="left"><code>Day-of-month</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>1-31</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * ? / L W</code></td> * </tr> * <tr> * <td align="left"><code>Month</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>0-11 or JAN-DEC</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * /</code></td> * </tr> * <tr> * <td align="left"><code>Day-of-Week</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>1-7 or SUN-SAT</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * ? / L #</code></td> * </tr> * <tr> * <td align="left"><code>Year (Optional)</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>empty, 1970-2199</code></td> * <td align="left">&nbsp;</th> * <td align="left"><code>, - * /</code></td> * </tr> * </table> * <P> * The '*' character is used to specify all values. For example, &quot;*&quot; in the * minute field means &quot;every minute&quot;. * <P> * 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. * <P> * The '-' character is used to specify ranges For example &quot;10-12&quot; in the hour * field means &quot;the hours 10, 11 and 12&quot;. * <P> * The ',' character is used to specify additional values. For example * &quot;MON,WED,FRI&quot; in the day-of-week field means &quot;the days Monday, * Wednesday, and Friday&quot;. * <P> * The '/' character is used to specify increments. For example &quot;0/15&quot; in the * seconds field means &quot;the seconds 0, 15, 30, and 45&quot;. And &quot;5/15&quot; in * the seconds field means &quot;the seconds 5, 20, 35, and 50&quot;. 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 &quot;/&quot; * character simply helps you turn on every &quot;nth&quot; value in the given set. Thus * &quot;7/6&quot; in the month field only turns on month &quot;7&quot;, it does NOT mean * every 6th month, please note that subtlety. * <P> * The 'L' character is allowed for the day-of-month and day-of-week fields. This * character is short-hand for &quot;last&quot;, but it has different meaning in each of * the two fields. For example, the value &quot;L&quot; in the day-of-month field means * &quot;the last day of the month&quot; - 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 * &quot;7&quot; or &quot;SAT&quot;. But if used in the day-of-week field after another * value, it means &quot;the last xxx day of the month&quot; - for example &quot;6L&quot; * means &quot;the last friday of the month&quot;. 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. <i>When using the 'L' option, it is important not to specify lists, or * ranges of values, as you'll get confusing/unexpected results.</i> * <P> * 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 &quot;15W&quot; as the value for the day-of-month field, the meaning is: * &quot;the nearest weekday to the 15th of the month&quot;. 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 &quot;1W&quot; 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. * <P> * The 'L' and 'W' characters can also be combined for the day-of-month expression to * yield 'LW', which translates to &quot;last weekday of the month&quot;. * <P> * The '#' character is allowed for the day-of-week field. This character is used to * specify &quot;the nth&quot; XXX day of the month. For example, the value of * &quot;6#3&quot; in the day-of-week field means the third Friday of the month (day 6 = * Friday and &quot;#3&quot; = the 3rd one in the month). Other examples: &quot;2#1&quot; * = the first Monday of the month and &quot;4#5&quot; = the fifth Wednesday of the month. * Note that if you specify &quot;#5&quot; 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 (&quot;3#1,6#3&quot; is not valid, * since there are two expressions). * <P> * <!--The 'C' character is allowed for the day-of-month and day-of-week fields. This * character is short-hand for "calendar". This means values are calculated against the * associated calendar, if any. If no calendar is associated, then it is equivalent to * having an all-inclusive calendar. A value of "5C" in the day-of-month field means "the * first day included by the calendar on or after the 5th". A value of "1C" in the * day-of-week field means "the first day included by the calendar on or after Sunday".--> * <P> * The legal characters and the names of months and days of the week are not case * sensitive. * * <p> * <b>NOTES:</b> * <ul> * <li>Support for specifying bo