此内容没有您所选择的语言版本。
Chapter 176. Timer
Timer Component
The timer: component is used to generate message exchanges when a timer fires You can only consume events from this endpoint.
URI format
timer:name[?options]
Where
name is the name of the Timer object, which is created and shared across endpoints. So if you use the same name for all your timer endpoints, only one Timer object and thread will be used.
You can append query options to the URI in the following format,
?option=value&option=value&...
Note: The IN body of the generated exchange is
null. So exchange.getIn().getBody() returns null.
Advanced Scheduler
See also the Quartz component that supports much more advanced scheduling.
Specify time in human friendly format
In Camel 2.3 onwards you can specify the time in human friendly syntax.
Options
| Name | Default Value | Description |
|---|---|---|
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
|
1000
|
The number of milliseconds to wait before the first event is generated. Should not be used in conjunction with the time option. From Camel 2.17 is possible to specify a negative delay. In this scenario the timer will generate and fire events as soon as possible.
|
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. |
Exchange Properties
When the timer is fired, it adds the following information as properties to the
Exchange:
| Name | Type | Description |
|---|---|---|
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. |
Message Headers
When the timer is fired, it adds the following information as headers to the IN message
| Name | Type | Description |
|---|---|---|
Exchange.TIMER_FIRED_TIME
|
java.util.Date
|
The time when the consumer fired |
Sample
To set up a route that generates an event every 60 seconds:
from("timer://foo?fixedRate=true&period=60000").to("bean:myBean?method=someMethodName");Tip
Instead of 60000 you can specify the more readable,
period=60s.
The above route will generate an event and then invoke the
someMethodName method on the bean called myBean in the Registry such as JNDI or Spring.
And the route in Spring DSL:
<route>
<from uri="timer://foo?fixedRate=true&period=60000"/>
<to uri="bean:myBean?method=someMethodName"/>
</route>Firing as soon as possible
Camel 2.17: You may want to fire messages in a Camel route as soon as possible you can use a negative delay:
<route>
<from uri="timer://foo?delay=-1"/>
<to uri="bean:myBean?method=someMethodName"/>
</route>
In this way the timer will fire messages immediately. You can also specify a
repeatCount parameter in conjunction with a negative delay to stop firing messages after a fixed number has been reached. If you don't specify a repeatCount, the timer will continue firing messages until the route is stopped.
Firing only once
Available as of Camel 2.8
You may want to fire a message in a Apache Camel route only once, such as when starting the route. To do that, you use the
repeatCount option as follows:
<route>
<from uri="timer://foo?repeatCount=1"/>
<to uri="bean:myBean?method=someMethodName"/>
</route>
See also:
