spring 定时任务的具体实现

spring 定时任务用MethodInvokingJobDetailFactoryBean，CronTriggerBean和SchedulerFactoryBean具体实现

MethodInvokingJobDetailFactoryBean 一般用于经常需要执行的定时任务，

具体配置如下

<bean id="exampleJob" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">  <property name="targetObject" ref="exampleBusinessObject" />  <property name="targetMethod" value="doIt" />  <property name="concurrent" value="false" /></bean><bean id="exampleBusinessObject" class="examples.ExampleBusinessObject"/>

注：声明了一个bean 具体执行哪个类的哪个方法，并且是以非并发的情况下执行，默认是并发执行，
设置非并发的好处，是在有两个或者以上的相同名字的jobDetail执行时，等一个执行完毕，在执行另外一个，不会造成冲突，

ExampleBusinessObject 类的结构

public class ExampleBusinessObject {  // properties and collaborators  public void doIt() {    // do the actual work  }}

上面只是声明了一个任务，但是没有说明这个任务什么时候执行，这个时候就要用到CronTriggerBean

<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">    <property name="jobDetail" ref="exampleJob" />    <!-- run every morning at 6 AM -->    <property name="cronExpression" value="0 0 6 * * ?" /></bean>

到了这里，就得用到SchedulerFactoryBean用来管理triggers，这样在spring容器启动的时候绑定好这些triggers

具体配置

<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">    <property name="triggers">        <list>            <ref bean="cronTrigger" />        </list>    </property></bean>

SchedulerFactoryBean更多的属性可以用来配置，例如任务要用到的日历，自定义自己的任务，想要更多信息请查看SchedulerFactoryBean Javadoc

网址为 http://static.springsource.org/spring-framework/docs/current/javadoc-api/org/springframework/scheduling/quartz/SchedulerFactoryBean.html

最后只要写一个main方法，加载好这些配置文件就行了,等到了作业的具体运行时间，就会运行作业了

public static void main(String[] args) {  ApplicationContext context = new ClassPathXmlApplicationContext("classpath:spring-*.xml");}

拓展一下 CronTriggerBean 里面一个属性 coreExpression 的具体语法

参照官网的api文档：http://quartz-scheduler.org/api/1.8.5/

属性 值范围 字符范围秒 0-59 , - * /分 0-59 , - * /时 0-23 , - * /天 1-31 , - * ? / L W月 1-12 or JAN-DEC , - * /星期 1-7 or SUN-SAT , - * ? / L #年(可选) empty, 1970-2199 , - * /

'*' 字符 值都可用。例如， "*"是分属性的值时，表示每分钟

 '?' 字符只可用于星期和天，用来表达没有固定的值，在两个可用的地方，不能同时出现?

 '-' 字符常用于指定特定的范围，例如"10-12"在时间域上表示10, 11 和 12"。

 ',' 字符常用于指定特殊的值，例如 "MON,WED,FRI" 意味着："the days Monday, Wednesday, and Friday"。

 '/' 字符常用于指定特殊的增量，例如"0/15" 在秒上表示"the seconds 0, 15, 30, and 45"。另外一个例子"5/15"在秒上表示"the seconds 5, 20, 35, and 50"。比如说'0/*'和*是一样的意思。并且要知道'/'字符前面的那个也是有范围的，在秒里面有0-59个选择，在星期里就只有1-7个选择，在天里就只有1-31个选择，还有一点'/'前面那个是多少，表示从这个开始。

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". When using the 'L' option, it is important not to specify lists, or ranges of values, as you'll get confusing results.

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.

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".

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).

The legal characters and the names of months and days of the week are not case sensitive.

NOTES:

• Support for specifying both a day-of-week and a day-of-month value is not complete (you'll need to use the '?' character in one of these fields).
• Overflowing ranges is supported - that is, having a larger number on the left hand side than the right. You might do 22-2 to catch 10 o'clock at night until 2 o'clock in the morning, or you might have NOV-FEB. It is very important to note that overuse of overflowing ranges creates ranges that don't make sense and no effort has been made to determine which interpretation CronExpression chooses. An example would be "0 0 14-6 ? * FRI-MON".

Here are some full examples:

Expression Meaning"0 0 12 * * ?" Fire at 12pm (noon) every day"0 15 10 ? * *" Fire at 10:15am every day"0 15 10 * * ?" Fire at 10:15am every day"0 15 10 * * ? *" Fire at 10:15am every day"0 15 10 * * ? 2005" Fire at 10:15am every day during the year 2005"0 * 14 * * ?" Fire every minute starting at 2pm and ending at 2:59pm, every day"0 0/5 14 * * ?" Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day"0 0/5 14,18 * * ?" Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day"0 0-5 14 * * ?" Fire every minute starting at 2pm and ending at 2:05pm, every day"0 10,44 14 ? 3 WED" Fire at 2:10pm and at 2:44pm every Wednesday in the month of March."0 15 10 ? * MON-FRI" Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday"0 15 10 15 * ?" Fire at 10:15am on the 15th day of every month"0 15 10 L * ?" Fire at 10:15am on the last day of every month"0 15 10 ? * 6L" Fire at 10:15am on the last Friday of every month"0 15 10 ? * 6L" Fire at 10:15am on the last Friday of every month"0 15 10 ? * 6L 2002-2005" Fire at 10:15am on every last Friday of every month during the years 2002, 2003, 2004 and 2005"0 15 10 ? * 6#3" Fire at 10:15am on the third Friday of every month

Pay attention to the effects of '?' and '*' in the day-of-week and day-of-month fields!

NOTES:

• Support for specifying both a day-of-week and a day-of-month value is not complete (you'll need to use the '?' character in on of these fields).
• Be careful when setting fire times between mid-night and 1:00 AM - "daylight savings" can cause a skip or a repeat depending on whether the time moves back or jumps forward.