Camel 组件之 Timer
http://www.xeclipse.com/?p=1053
Timer是常用的定时组件，下面简单讲解一下这个组件的基础用法。
作用：定时产生一条Message。
注意：这个组件仅仅能用作consumer，不能用作producer。简单地说，就是只能放在from()里面，不能放在to()里面。
Timer用法
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1
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timer:name[?options]
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非常简单，需要一个名字，以及必要的参数：
| 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 | 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产生的Message，带着特定的Properties，这些Properties分别为：
| 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. |
同时Message也有一个Header：
| Name | Type | Description |
|---|---|---|
| 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秒钟，产生一条Message，并将消息的内容设为Timer触发的时间：
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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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