http://www.xeclipse.com/?p=1053

Timer是常用的定時組件，下面簡單講解一下這個組件的基礎用法。

作用：定時產生一條Message。

注意：這個組件僅僅能用作consumer，不能用作producer。簡單地說，就是只能放在from()里面，不能放在to()里面。

Timer用法

1	timer:name[?options]

非常簡單，需要一個名字，以及必要的參數：

NameDefault ValueDescription

time	null	A?java.util.Date?the?first?event should be generated. If using the URI, the pattern expected is:?yyyy-MM-dd HH:mm:ss?or?yyyy-MM-dd'T'HH:mm:ss.
pattern	null	Allows you to specify a custom?Date?pattern to use for setting the time option using URI syntax.
period	1000	If greater than 0, generate periodic events every?period?milliseconds.
delay	0	The number of milliseconds to wait before the first event is generated. Should not be used in conjunction with the?time?option.
fixedRate	false	Events take place at approximately regular intervals, separated by the specified period.
daemon	true	Specifies whether or not the thread associated with the timer endpoint runs as a daemon.
repeatCount	0	Camel 2.8:?Specifies a maximum limit of number of fires. So if you set it to 1, the timer will only fire once. If you set it to 5, it will only fire five times. A value of zero or negative means fire forever.

Timer產生的Message，帶著特定的Properties，這些Properties分別為：

NameTypeDescription

Exchange.TIMER_NAME	String	The value of the?name?option.
Exchange.TIMER_TIME	Date	The value of the?time?option.
Exchange.TIMER_PERIOD	long	The value of the?period?option.
Exchange.TIMER_FIRED_TIME	Date	The time when the consumer fired.
Exchange.TIMER_COUNTER	Long	Camel 2.8:?The current fire counter. Starts from 1.

同時Message也有一個Header：

NameTypeDescription

Exchange.TIMER_FIRED_TIME	java.util.Date	The time when the consumer fired

Timer示例

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import org.apache.camel.CamelContext; import org.apache.camel.builder.RouteBuilder; import org.apache.camel.impl.DefaultCamelContext; ?? /** ?* A Camel Router ?*/ public class TimerRouteBuilder extends RouteBuilder { ?? ????/** ?????* A main() so we can easily run these routing rules in our IDE ?????*/ ????public static void main(String... args) throws Exception { ?? ????????CamelContext camelContext = new DefaultCamelContext(); ????????camelContext.addRoutes(new TimerRouteBuilder()); ????????camelContext.start(); ?? ????????Thread.sleep(100000000); ????} ?? ????/** ?????* Lets configure the Camel routing rules using Java code... ?????*/ ????public void configure() { ????????from("timer://myTimer?period=2000").setBody() ????????????????.simple("Current time is ${header.firedTime}").to("log:out"); ????} ?? }

每隔2秒鐘，產生一條Message，并將消息的內容設為Timer觸發的時間：

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[????????????????????????? main] 12 Feb 10 14:41:16,985 DefaultCamelContext??????????? INFO? Apache Camel 2.8.0 (CamelContext: camel-1) is starting [????????????????????????? main] 12 Feb 10 14:41:16,985 DefaultCamelContext??????????? INFO? JMX enabled. Using ManagedManagementStrategy. [????????????????????????? main] 12 Feb 10 14:41:17,315 AnnotationTypeConverterLoader? INFO? Found 3 packages with 14 @Converter classes to load [????????????????????????? main] 12 Feb 10 14:41:17,355 DefaultTypeConverter?????????? INFO? Loaded 153 core type converters (total 153 type converters) [????????????????????????? main] 12 Feb 10 14:41:17,375 AnnotationTypeConverterLoader? INFO? Loaded 4 @Converter classes [????????????????????????? main] 12 Feb 10 14:41:17,395 DefaultTypeConverter?????????? INFO? Loaded additional 22 type converters (total 175 type converters) in 0.040 seconds [????????????????????????? main] 12 Feb 10 14:41:17,805 DefaultCamelContext??????????? INFO? Route: route1 started and consuming from: Endpoint[timer://myTimer?period=2000] [????????????????????????? main] 12 Feb 10 14:41:17,805 DefaultCamelContext??????????? INFO? Total 1 routes, of which 1 is started. [????????????????????????? main] 12 Feb 10 14:41:17,805 DefaultCamelContext??????????? INFO? Apache Camel 2.8.0 (CamelContext: camel-1) started in 0.820 seconds [?????????????????????? myTimer] 12 Feb 10 14:41:17,846 out??????????????????????????? INFO? Exchange[ExchangePattern:InOnly, BodyType:String, Body:Current time is Fri Feb 10 14:41:17 CST 2012] [?????????????????????? myTimer] 12 Feb 10 14:41:19,806 out??????????????????????????? INFO? Exchange[ExchangePattern:InOnly, BodyType:String, Body:Current time is Fri Feb 10 14:41:19 CST 2012] [?????????????????????? myTimer] 12 Feb 10 14:41:21,807 out??????????????????????????? INFO? Exchange[ExchangePattern:InOnly, BodyType:String, Body:Current time is Fri Feb 10 14:41:21 CST 2012] [?????????????????????? myTimer] 12 Feb 10 14:41:23,808 out??????????????????????????? INFO? Exchange[ExchangePattern:InOnly, BodyType:String, Body:Current time is Fri Feb 10 14:41:23 CST 2012] [?????????????????????? myTimer] 12 Feb 10 14:41:25,809 out??????????????????????????? INFO? Exchange[ExchangePattern:InOnly, BodyType:String, Body:Current time is Fri Feb 10 14:41:25 CST 2012]

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