[[timer-component]]
== Timer Component

*Available as of Camel version 1.0*

The *timer:* component is used to generate message exchanges when a
timer fires You can only consume events from this endpoint.

=== URI format

[source]
----
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`.

TIP:*Advanced Scheduler*
See also the <<quartz-component,Quartz>> component that supports much more
advanced scheduling.

TIP:*Specify time in human friendly format*
In *Camel 2.3* onwards you can specify the time in
link:how-do-i-specify-time-period-in-a-human-friendly-syntax.html[human
friendly syntax].


=== Options

// component options: START
The Timer component has no options.
// component options: END


// endpoint options: START
The Timer endpoint is configured using URI syntax:

----
timer:timerName
----

with the following path and query parameters:

==== Path Parameters (1 parameters):


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|===
| Name | Description | Default | Type
| *timerName* | *Required* The name of the timer |  | String
|===


==== Query Parameters (12 parameters):


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|===
| Name | Description | Default | Type
| *bridgeErrorHandler* (consumer) | Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN/ERROR level and ignored. | false | boolean
| *delay* (consumer) | The number of milliseconds to wait before the first event is generated. Should not be used in conjunction with the time option. The default value is 1000. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour). | 1000 | long
| *fixedRate* (consumer) | Events take place at approximately regular intervals, separated by the specified period. | false | boolean
| *period* (consumer) | If greater than 0, generate periodic events every period milliseconds. The default value is 1000. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour). | 1000 | long
| *repeatCount* (consumer) | 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. | 0 | long
| *exceptionHandler* (consumer) | To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions, that will be logged at WARN/ERROR level and ignored. |  | ExceptionHandler
| *exchangePattern* (consumer) | Sets the default exchange pattern when creating an exchange. |  | ExchangePattern
| *daemon* (advanced) | Specifies whether or not the thread associated with the timer endpoint runs as a daemon. The default value is true. | true | boolean
| *pattern* (advanced) | Allows you to specify a custom Date pattern to use for setting the time option using URI syntax. |  | String
| *synchronous* (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean
| *time* (advanced) | 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. |  | Date
| *timer* (advanced) | To use a custom Timer |  | Timer
|===
// endpoint options: END


=== Exchange Properties

When the timer is fired, it adds the following information as properties
to the `Exchange`:

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|===
|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.
|===

=== Sample

To set up a route that generates an event every 60 seconds:

[source,java]
----
from("timer://foo?fixedRate=true&period=60000").to("bean:myBean?method=someMethodName");
----

TIP: Instead of 60000 you can use period=60s which is more friendly to read.

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:

[source,xml]
-----
<route>
  <from uri="timer://foo?fixedRate=true&amp;period=60000"/>
  <to uri="bean:myBean?method=someMethodName"/>
</route>
-----

=== Firing as soon as possible

*Available as of Camel 2.17*

You may want to fire messages in a Camel route as soon as possible you
can use a negative delay:

[source,xml]
----
<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 then the timer will continue firing
messages until the route will be stopped. 

=== Firing only once

*Available as of Camel 2.8*

You may want to fire a message in a Camel route only once, such as when
starting the route. To do that you use the repeatCount option as shown:

[source,xml]
----
<route>
  <from uri="timer://foo?repeatCount=1"/>
  <to uri="bean:myBean?method=someMethodName"/>
</route>
----

=== See Also

* <<scheduler-component,Scheduler>>
* <<quartz-component,Quartz>>
