Apache Camel - 17 - Timer组件
Apache Camel Timer定时器组件
我将整理好的代码，上传了，有兴趣的同学可以下载下来跑跑看....
Apache Camel Timer组件 代码Demo
Apache Camel相关代码已经上传GitHub，需要的自取：GitHub - Apache Camel 完整Demo
如果觉得还行，麻烦点个Star
Timer Component定时器组件
The timer: component is used to generate message exchanges when a timer fires You can only consume events from this endpoint.
timer：组件用于在定时器触发时生成消息交换。您只能使用此端点的事件。
URI format URI格式
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.
其中，name是定时器对象的名称，它是通过端点创建和共享的。
所以，如果你为所有的定时器端点使用相同的名字，将只使用一个Timer对象和线程。
You can append query options to the URI in the following format,?option=value&option=value&...
您可以按照以下格式将查询选项追加到URI中：?option=value&option=value&...
Note: The IN body of the generated exchange is null. So exchange.getIn().getBody() returns null.
注意：生成的交换的in body为空。 所以exchange.getIn().getBody()返回null。
Advanced Scheduler
See also the Quartz component that supports much more advanced scheduling.
高级调度程序
另请参阅支持更多高级调度的Quartz组件。
Options选项
| Option |
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. 一个java.util.Date应该生成第一个事件。 如果使用URI，预期的模式是：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. 允许您指定自定义日期模式，以使用URI语法设置时间选项。 |
| period |
1000 |
If greater than 0, generate periodic events every period milliseconds. 如果大于0，则在每个毫秒时间内生成周期性事件。 |
| delay |
0 |
The number of milliseconds to wait before the first event is generated. Should not be used in conjunction with the time option. 生成第一个事件之前要等待的毫秒数。 不应该与时间选项一起使用。 |
| fixedRate |
false |
Events take place at approximately regular intervals, separated by the specified period. 事件发生在大约固定的时间间隔，由指定的时间隔开。 |
| daemon |
true |
Specifies whether or not the thread associated with the timer endpoint runs as a daemon. 指定与定时器端点关联的线程是否作为守护程序运行。 |
| 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交换属性
When the timer is fired, it adds the following information as properties to the Exchange:
计时器启动后，它将以下信息作为属性添加到Exchange中：
| 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 消息头
When the timer is fired, it adds the following information as headers to the IN message
当定时器被触发时，它将以下信息作为标题添加到in message中
| name |
type |
Description |
| Exchange.TIMER_FIRED_TIME |
java.util.Date |
The time when the consumer fired |
Sample样品
To set up a route that generates an event every 60 seconds:
要设置每60秒生成一个事件的路由，请执行以下操作：
from("timer://foo?fixedRate=true&period=60000").to("bean:myBean?method=someMethodName");Instead of 60000 you can use period=60s which is more friendly to read.
而不是60000，你可以使用周期= 60s，这是更友好的阅读。
----------------------------------------------------------------------------------------------------------------------------------------
下面看看《Camel in Action》书中内容
Automating tasks (Timer and Quartz components)
自动化任务（定时器和Quartz组件）
Often in enterprise projects you’ll need to schedule tasks to occur either at a specified time or at regular intervals.
通常在企业项目中，您需要安排任务在指定的时间或定期进行。
Camel supports this kind of service with the Timer and Quartz components.
Camel支持使用Timer和Quartz组件的这种服务。
The Timer component is useful for simple recurring tasks, but when you need more control of when things get started, the Quartz component is a must.
Timer组件对于简单的循环任务是有用的，但是当你需要更多的控制什么时候开始的时候，Quartz组件是必须的。
In this section, we’re first going to look at the Timer component and then move on to the more advanced Quartz component.
在本节中，我们将首先看看Timer组件，然后转到更高级的Quartz组件。
Using the Timer component使用Timer组件
The Timer component comes with Camel’s core library and uses the JRE’s built-in timer mechanism to generate message exchanges at regular intervals.
Timer组件带有Camel的核心库，并使用JRE的内置定时器机制来定期生成消息交换。
This component only supports consuming, because sending to a timer doesn’t really make sense.
这个组件只支持消费，因为发送到一个定时器并没有什么意义。
As an example, let’s print a message stating the time to the console every 2 seconds.
The route looks like this:
作为一个例子，让我们每2秒打一条消息给控制台。
路线如下所示：
from("timer://myTimer?period=2000").setBody().simple("Current time is ${header.firedTime}").to("stream:out");The timer URI is configuring the underlying java.util.Timer to have the name myTimer and an execution interval of 2000 milliseconds.
计时器URI正在配置底层的java.util.Timer，名称为myTimer，执行间隔为2000毫秒。
TIP When the value of milliseconds gets large, you can opt for a shorter notation using the s, m, and h keywords.
提示当毫秒值变大时，可以使用s，m和h关键字选择较短的记法。
For example, 2000 milliseconds can be written as 2s, meaning 2 seconds. 90000 milliseconds can be written as 1m30s,and so on
例如，2000毫秒可以写成2秒，意思是2秒。 90000毫秒可以写成1m30s等等
下面看看Demo代码：
package com.camel.timer.server;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.camel.model.ModelCamelContext;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
public class CamelTimerServer {
public static final Logger logger = Logger.getLogger(CamelTimerServer.class);
public static void main(String[] args) {
// 日志
PropertyConfigurator.configure("./conf/log4j.properties");
PropertyConfigurator.configureAndWatch("./conf/log4j.properties", 1000);
try {
// 这是camel上下文对象，整个路由的驱动全靠它了。
ModelCamelContext camelContext = new DefaultCamelContext();
// 启动route
camelContext.start();
camelContext.addRoutes(new RouteBuilder() {
@Override
public void configure() throws Exception {
from("timer://myTimer?period=2s")
.setBody().simple("Current time is ${header.firedTime}")
.to("log:CamelTimerServer?showExchangeId=true");
}
});
// 通用没有具体业务意义的代码，只是为了保证主线程不退出
synchronized (CamelTimerServer.class) {
CamelTimerServer.class.wait();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}
运行之后的结果：
再来一个Demo
定时器 运行定时业务代码：
package com.camel.timer.server;
import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.impl.DefaultCamelContext;
import org.apache.camel.model.ModelCamelContext;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
public class CamelTimerServer2 {
public static final Logger logger = Logger.getLogger(CamelTimerServer2.class);
public static void main(String[] args) {
// 日志
PropertyConfigurator.configure("./conf/log4j.properties");
PropertyConfigurator.configureAndWatch("./conf/log4j.properties", 1000);
try {
ModelCamelContext camelContext = new DefaultCamelContext();
camelContext.start();
camelContext.addRoutes(new RouteBuilder() {
@Override
public void configure() throws Exception {
from("timer://foo?period=2s").process(new Processor() {
public void process(Exchange exchange) throws Exception {
logger.info("Hello world :" + System.currentTimeMillis());
}
});
}
});
// 没有具体业务意义的代码，只是为了保证主线程不退出
synchronized (CamelTimerServer2.class) {
CamelTimerServer2.class.wait();
}
} catch (Exception e) {
logger.error(e.getMessage(), e);
}
}
}
运行结果
How do I specify time period in a human friendly syntax
如何以人性化的语法指定时间段？
Available as of Camel 2.3
适用于Camel2.3
Some of the Camel components offers options to specify a time period, which must be entered in milli second as unit.
This may be unfriendly to read as a human when the value is large such as 45min = 2700000 millis.
一些Camel组件提供了选项来指定一个时间段，必须以毫秒为单位进行输入。
当数值很大时，如45分钟= 270万毫米，这可能是不友好的。
So in Camel 2.3 you can now configure any endpoint uri parameter using a String syntax, which at runtime will get converted to millis (long type).
因此，在Camel 2.3中，现在可以使用String语法来配置任何端点的uri参数，在运行时将会将其转换为millis（long类型）。
You can use the following short syntax, which is most common to use:
您可以使用以下最常用的简短语法：
| Syntax |
Unit |
| h |
hour |
| m |
minute |
| s |
second |
So for example the Timer endpoint can be configured as follows
因此，例如，定时器端点可以配置如下
from("timer:foo?period=45m").to("log:foo");
You can mix and match the units so you can do this as well:
你可以混合和匹配单位，所以你也可以这样做：
from("timer:foo?period=1h15m").to("log:foo");
from("timer:bar?period=2h30s").to("log:bar");
from("timer:bar?period=3h45m58s").to("log:bar");
However you can also use long syntax
但是，你也可以使用长的语法
| Syntax |
Unit |
| hour or hours |
hour |
| minute or minutes |
minute |
| second or seconds |
second |
from("timer:foo?period=45minutes").to("log:foo");
参考来源：
http://www.pretechsol.com/2014/07/camel-timer-example_85.html
http://camel.apache.org/timer.html
http://camel.apache.org/how-do-i-specify-time-period-in-a-human-friendly-syntax.html