Moved Quartz and Timer discussion after TaskExecutor and TaskScheduler
This commit is contained in:
Mark Fisher
parent
a07da0d950
commit
b5661ebd12
|
|
@ -19,252 +19,6 @@
|
|||
away differences between Java SE 1.4, Java SE 5 and Java EE environments.
|
||||
</para>
|
||||
</section>
|
||||
<section id="scheduling-quartz">
|
||||
<title>Using the OpenSymphony Quartz Scheduler</title>
|
||||
<para>Quartz uses <classname>Trigger</classname>, <classname>Job</classname> and
|
||||
<classname>JobDetail</classname> objects to realize scheduling of all kinds of jobs.
|
||||
For the basic concepts behind Quartz, have a look at
|
||||
<ulink url="http://www.opensymphony.com/quartz" />. For convenience purposes,
|
||||
Spring offers a couple of classes that simplify the usage of Quartz within
|
||||
Spring-based applications.
|
||||
</para>
|
||||
<section id="scheduling-quartz-jobdetail">
|
||||
<title>Using the JobDetailBean</title>
|
||||
<para>
|
||||
<classname>JobDetail</classname> objects contain all information needed to
|
||||
run a job. The Spring Framework provides a <classname>JobDetailBean</classname>
|
||||
that makes the <classname>JobDetail</classname> more of an actual JavaBean
|
||||
with sensible defaults. Let's have a look at an example:
|
||||
</para>
|
||||
<programlisting language="xml"><![CDATA[
|
||||
<bean name="exampleJob" class="org.springframework.scheduling.quartz.JobDetailBean">
|
||||
<property name="jobClass" value="example.ExampleJob" />
|
||||
<property name="jobDataAsMap">
|
||||
<map>
|
||||
<entry key="timeout" value="5" />
|
||||
</map>
|
||||
</property>
|
||||
</bean>]]></programlisting>
|
||||
<para>The job detail bean has all information it needs to run the job (<classname>ExampleJob</classname>).
|
||||
The timeout is specified in the job data map. The job data map is
|
||||
available through the <classname>JobExecutionContext</classname>
|
||||
(passed to you at execution time), but the <classname>JobDetailBean</classname>
|
||||
also maps the properties from the job data map to properties of the actual job.
|
||||
So in this case, if the <classname>ExampleJob</classname> contains a property
|
||||
named <literal>timeout</literal>, the <classname>JobDetailBean</classname> will
|
||||
automatically apply it:</para>
|
||||
<programlisting language="java"><![CDATA[package example;
|
||||
|
||||
public class ExampleJob extends QuartzJobBean {
|
||||
|
||||
private int timeout;
|
||||
|
||||
/**
|
||||
* Setter called after the ExampleJob is instantiated
|
||||
* with the value from the JobDetailBean (5)
|
||||
*/
|
||||
public void setTimeout(int timeout) {
|
||||
this.timeout = timeout;
|
||||
}
|
||||
|
||||
protected void executeInternal(JobExecutionContext ctx) throws JobExecutionException {
|
||||
]]><lineannotation>// do the actual work</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
<para>All additional settings from the job detail bean are of course available to you as well.</para>
|
||||
<para><emphasis>Note: Using the <literal>name</literal> and <literal>group</literal> properties,
|
||||
you can modify the name and the group of the job, respectively. By default, the name of
|
||||
the job matches the bean name of the job detail bean (in the example above, this is
|
||||
<literal>exampleJob</literal>).</emphasis></para>
|
||||
</section>
|
||||
<section id="scheduling-quartz-method-invoking-job">
|
||||
<title>Using the <classname>MethodInvokingJobDetailFactoryBean</classname></title>
|
||||
<para>Often you just need to invoke a method on a specific object. Using the
|
||||
<classname>MethodInvokingJobDetailFactoryBean</classname> you can do exactly this:</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="jobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
|
||||
<property name="targetObject" ref="exampleBusinessObject" />
|
||||
<property name="targetMethod" value="doIt" />
|
||||
</bean>]]></programlisting>
|
||||
<para>The above example will result in the <literal>doIt</literal> method being called on the
|
||||
<literal>exampleBusinessObject</literal> method (see below):</para>
|
||||
<programlisting language="java"><![CDATA[public class ExampleBusinessObject {
|
||||
|
||||
]]><lineannotation>// properties and collaborators</lineannotation><![CDATA[
|
||||
|
||||
public void doIt() {
|
||||
]]><lineannotation>// do the actual work</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
|
||||
<programlisting language="xml"><![CDATA[
|
||||
<bean id="exampleBusinessObject" class="examples.ExampleBusinessObject"/>]]></programlisting>
|
||||
<para>Using the <classname>MethodInvokingJobDetailFactoryBean</classname>, you don't need to
|
||||
create one-line jobs that just invoke a method, and you only need to create the actual
|
||||
business object and wire up the detail object.</para>
|
||||
<para>By default, Quartz Jobs are stateless, resulting in the possibility of jobs interfering
|
||||
with each other. If you specify two triggers for the same <classname>JobDetail</classname>,
|
||||
it might be possible that before the first job has finished, the second one will start.
|
||||
If <classname>JobDetail</classname> classes implement the
|
||||
<interfacename>Stateful</interfacename> interface, this won't happen. The second job
|
||||
will not start before the first one has finished. To make jobs resulting from the
|
||||
<classname>MethodInvokingJobDetailFactoryBean</classname> non-concurrent, set the
|
||||
<literal>concurrent</literal> flag to <literal>false</literal>.</para>
|
||||
<programlisting language="xml"><![CDATA[
|
||||
<bean id="jobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
|
||||
<property name="targetObject" ref="exampleBusinessObject" />
|
||||
<property name="targetMethod" value="doIt" />
|
||||
<property name="concurrent" value="false" />
|
||||
</bean>]]></programlisting>
|
||||
<note>
|
||||
<para>By default, jobs will run in a concurrent fashion.</para>
|
||||
</note>
|
||||
</section>
|
||||
<section id="scheduling-quartz-cron">
|
||||
<title>Wiring up jobs using triggers and the <classname>SchedulerFactoryBean</classname></title>
|
||||
<para>
|
||||
We've created job details and jobs. We've also reviewed the convenience bean
|
||||
that allows to you invoke a method on a specific object. Of course, we still need
|
||||
to schedule the jobs themselves. This is done using triggers and a
|
||||
<classname>SchedulerFactoryBean</classname>. Several triggers are available
|
||||
within Quartz. Spring offers two subclassed triggers with convenient defaults:
|
||||
<classname>CronTriggerBean</classname> and <classname>SimpleTriggerBean</classname>.
|
||||
</para>
|
||||
<para>
|
||||
Triggers need to be scheduled. Spring offers a <classname>SchedulerFactoryBean</classname>
|
||||
that exposes triggers to be set as properties. <classname>SchedulerFactoryBean</classname>
|
||||
schedules the actual jobs with those triggers.
|
||||
</para>
|
||||
<para>Find below a couple of examples:</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
|
||||
<!-- see the example of method invoking job above -->
|
||||
<property name="jobDetail" ref="jobDetail" />
|
||||
<!-- 10 seconds -->
|
||||
<property name="startDelay" value="10000" />
|
||||
<!-- repeat every 50 seconds -->
|
||||
<property name="repeatInterval" value="50000" />
|
||||
</bean>
|
||||
|
||||
<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
|
||||
<property name="jobDetail" ref="exampleJob" />
|
||||
<!-- run every morning at 6 AM -->
|
||||
<property name="cronExpression" value="0 0 6 * * ?" />
|
||||
</bean>]]></programlisting>
|
||||
<para>Now we've set up two triggers, one running every 50 seconds with a starting delay of
|
||||
10 seconds and one every morning at 6 AM. To finalize everything, we need to set up the
|
||||
<classname>SchedulerFactoryBean</classname>:</para>
|
||||
<programlisting language="xml"><![CDATA[<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
|
||||
<property name="triggers">
|
||||
<list>
|
||||
<ref bean="cronTrigger" />
|
||||
<ref bean="simpleTrigger" />
|
||||
</list>
|
||||
</property>
|
||||
</bean>]]></programlisting>
|
||||
<para>
|
||||
More properties are available for the <classname>SchedulerFactoryBean</classname> for you
|
||||
to set, such as the calendars used by the job details, properties to customize Quartz with,
|
||||
etc. Have a look at the
|
||||
<ulink url="http://static.springframework.org/spring/docs/2.5.x/api/org/springframework/scheduling/quartz/SchedulerFactoryBean.html">SchedulerFactoryBean Javadoc</ulink>
|
||||
for more information.
|
||||
</para>
|
||||
</section>
|
||||
</section>
|
||||
<section id="scheduling-jdk-timer">
|
||||
<title>Using JDK Timer support</title>
|
||||
<para>
|
||||
The other way to schedule jobs in Spring is to use JDK
|
||||
<classname>Timer</classname> objects. You can create custom timers or
|
||||
use the timer that invokes methods. Wiring timers is done using the
|
||||
<classname>TimerFactoryBean</classname>.
|
||||
</para>
|
||||
<section id="scheduling-jdk-timer-creating">
|
||||
<title>Creating custom timers</title>
|
||||
<para>
|
||||
Using the <classname>TimerTask</classname> you can create customer
|
||||
timer tasks, similar to Quartz jobs:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[public class CheckEmailAddresses extends TimerTask {
|
||||
|
||||
private List emailAddresses;
|
||||
|
||||
public void setEmailAddresses(List emailAddresses) {
|
||||
this.emailAddresses = emailAddresses;
|
||||
}
|
||||
|
||||
public void run() {
|
||||
]]><lineannotation>// iterate over all email addresses and archive them</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
<para>
|
||||
Wiring it up is simple:
|
||||
</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="checkEmail" class="examples.CheckEmailAddress">
|
||||
<property name="emailAddresses">
|
||||
<list>
|
||||
<value>test@springframework.org</value>
|
||||
<value>foo@bar.com</value>
|
||||
<value>john@doe.net</value>
|
||||
</list>
|
||||
</property>
|
||||
</bean>
|
||||
|
||||
<bean id="scheduledTask" class="org.springframework.scheduling.timer.ScheduledTimerTask">
|
||||
]]><lineannotation><!-- wait 10 seconds before starting repeated execution --></lineannotation><![CDATA[
|
||||
<property name="delay" value="10000" />
|
||||
]]><lineannotation><!-- run every 50 seconds --></lineannotation><![CDATA[
|
||||
<property name="period" value="50000" />
|
||||
<property name="timerTask" ref="checkEmail" />
|
||||
</bean>]]></programlisting>
|
||||
<para>
|
||||
<emphasis>
|
||||
Note that letting the task only run once can be done by changing the
|
||||
<literal>period</literal> property to 0 (or a negative value).
|
||||
</emphasis>
|
||||
</para>
|
||||
</section>
|
||||
<section id="scheduling-jdk-timer-method-invoking-task">
|
||||
<title>Using the <classname>MethodInvokingTimerTaskFactoryBean</classname></title>
|
||||
<para>
|
||||
Similar to the Quartz support, the <classname>Timer</classname> support also features
|
||||
a component that allows you to periodically invoke a method:
|
||||
</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="doIt" class="org.springframework.scheduling.timer.MethodInvokingTimerTaskFactoryBean">
|
||||
<property name="targetObject" ref="exampleBusinessObject" />
|
||||
<property name="targetMethod" value="doIt" />
|
||||
</bean>]]></programlisting>
|
||||
<para>
|
||||
The above example will result in the <literal>doIt</literal> method being called on the
|
||||
<literal>exampleBusinessObject</literal> (see below):
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[public class BusinessObject {
|
||||
|
||||
]]><lineannotation>// properties and collaborators</lineannotation><![CDATA[
|
||||
|
||||
public void doIt() {
|
||||
]]><lineannotation>// do the actual work</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
<para>Changing the <literal>timerTask</literal> reference of the
|
||||
<classname>ScheduledTimerTask</classname> example to the bean <literal>doIt</literal>
|
||||
will result in the <literal>doIt</literal> method being executed on a fixed schedule.</para>
|
||||
</section>
|
||||
<section id="scheduling-jdk-timer-factory-bean">
|
||||
<title>Wrapping up: setting up the tasks using the <classname>TimerFactoryBean</classname></title>
|
||||
<para>The <classname>TimerFactoryBean</classname> is similar to the Quartz
|
||||
<classname>SchedulerFactoryBean</classname> in that it serves the same
|
||||
purpose: setting up the actual scheduling. The <classname>TimerFactoryBean</classname>
|
||||
sets up an actual <classname>Timer</classname> and schedules the tasks it has
|
||||
references to. You can specify whether or not daemon threads should be used.</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="timerFactory" class="org.springframework.scheduling.timer.TimerFactoryBean">
|
||||
<property name="scheduledTimerTasks">
|
||||
<list>
|
||||
]]><lineannotation><!-- see the example above --></lineannotation><![CDATA[
|
||||
<ref bean="scheduledTask" />
|
||||
</list>
|
||||
</property>
|
||||
</bean>]]></programlisting>
|
||||
</section>
|
||||
</section>
|
||||
<section id="scheduling-task-executor">
|
||||
<title>The Spring <interfacename>TaskExecutor</interfacename> abstraction</title>
|
||||
|
||||
|
|
@ -622,5 +376,251 @@ public class TaskExecutorExample {
|
|||
as scheduled, and potentially recurring, executions.</para>
|
||||
</section>
|
||||
</section>
|
||||
<section id="scheduling-quartz">
|
||||
<title>Using the OpenSymphony Quartz Scheduler</title>
|
||||
<para>Quartz uses <classname>Trigger</classname>, <classname>Job</classname> and
|
||||
<classname>JobDetail</classname> objects to realize scheduling of all kinds of jobs.
|
||||
For the basic concepts behind Quartz, have a look at
|
||||
<ulink url="http://www.opensymphony.com/quartz" />. For convenience purposes,
|
||||
Spring offers a couple of classes that simplify the usage of Quartz within
|
||||
Spring-based applications.
|
||||
</para>
|
||||
<section id="scheduling-quartz-jobdetail">
|
||||
<title>Using the JobDetailBean</title>
|
||||
<para>
|
||||
<classname>JobDetail</classname> objects contain all information needed to
|
||||
run a job. The Spring Framework provides a <classname>JobDetailBean</classname>
|
||||
that makes the <classname>JobDetail</classname> more of an actual JavaBean
|
||||
with sensible defaults. Let's have a look at an example:
|
||||
</para>
|
||||
<programlisting language="xml"><![CDATA[
|
||||
<bean name="exampleJob" class="org.springframework.scheduling.quartz.JobDetailBean">
|
||||
<property name="jobClass" value="example.ExampleJob" />
|
||||
<property name="jobDataAsMap">
|
||||
<map>
|
||||
<entry key="timeout" value="5" />
|
||||
</map>
|
||||
</property>
|
||||
</bean>]]></programlisting>
|
||||
<para>The job detail bean has all information it needs to run the job (<classname>ExampleJob</classname>).
|
||||
The timeout is specified in the job data map. The job data map is
|
||||
available through the <classname>JobExecutionContext</classname>
|
||||
(passed to you at execution time), but the <classname>JobDetailBean</classname>
|
||||
also maps the properties from the job data map to properties of the actual job.
|
||||
So in this case, if the <classname>ExampleJob</classname> contains a property
|
||||
named <literal>timeout</literal>, the <classname>JobDetailBean</classname> will
|
||||
automatically apply it:</para>
|
||||
<programlisting language="java"><![CDATA[package example;
|
||||
|
||||
public class ExampleJob extends QuartzJobBean {
|
||||
|
||||
private int timeout;
|
||||
|
||||
/**
|
||||
* Setter called after the ExampleJob is instantiated
|
||||
* with the value from the JobDetailBean (5)
|
||||
*/
|
||||
public void setTimeout(int timeout) {
|
||||
this.timeout = timeout;
|
||||
}
|
||||
|
||||
protected void executeInternal(JobExecutionContext ctx) throws JobExecutionException {
|
||||
]]><lineannotation>// do the actual work</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
<para>All additional settings from the job detail bean are of course available to you as well.</para>
|
||||
<para><emphasis>Note: Using the <literal>name</literal> and <literal>group</literal> properties,
|
||||
you can modify the name and the group of the job, respectively. By default, the name of
|
||||
the job matches the bean name of the job detail bean (in the example above, this is
|
||||
<literal>exampleJob</literal>).</emphasis></para>
|
||||
</section>
|
||||
<section id="scheduling-quartz-method-invoking-job">
|
||||
<title>Using the <classname>MethodInvokingJobDetailFactoryBean</classname></title>
|
||||
<para>Often you just need to invoke a method on a specific object. Using the
|
||||
<classname>MethodInvokingJobDetailFactoryBean</classname> you can do exactly this:</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="jobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
|
||||
<property name="targetObject" ref="exampleBusinessObject" />
|
||||
<property name="targetMethod" value="doIt" />
|
||||
</bean>]]></programlisting>
|
||||
<para>The above example will result in the <literal>doIt</literal> method being called on the
|
||||
<literal>exampleBusinessObject</literal> method (see below):</para>
|
||||
<programlisting language="java"><![CDATA[public class ExampleBusinessObject {
|
||||
|
||||
]]><lineannotation>// properties and collaborators</lineannotation><![CDATA[
|
||||
|
||||
public void doIt() {
|
||||
]]><lineannotation>// do the actual work</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
|
||||
<programlisting language="xml"><![CDATA[
|
||||
<bean id="exampleBusinessObject" class="examples.ExampleBusinessObject"/>]]></programlisting>
|
||||
<para>Using the <classname>MethodInvokingJobDetailFactoryBean</classname>, you don't need to
|
||||
create one-line jobs that just invoke a method, and you only need to create the actual
|
||||
business object and wire up the detail object.</para>
|
||||
<para>By default, Quartz Jobs are stateless, resulting in the possibility of jobs interfering
|
||||
with each other. If you specify two triggers for the same <classname>JobDetail</classname>,
|
||||
it might be possible that before the first job has finished, the second one will start.
|
||||
If <classname>JobDetail</classname> classes implement the
|
||||
<interfacename>Stateful</interfacename> interface, this won't happen. The second job
|
||||
will not start before the first one has finished. To make jobs resulting from the
|
||||
<classname>MethodInvokingJobDetailFactoryBean</classname> non-concurrent, set the
|
||||
<literal>concurrent</literal> flag to <literal>false</literal>.</para>
|
||||
<programlisting language="xml"><![CDATA[
|
||||
<bean id="jobDetail" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
|
||||
<property name="targetObject" ref="exampleBusinessObject" />
|
||||
<property name="targetMethod" value="doIt" />
|
||||
<property name="concurrent" value="false" />
|
||||
</bean>]]></programlisting>
|
||||
<note>
|
||||
<para>By default, jobs will run in a concurrent fashion.</para>
|
||||
</note>
|
||||
</section>
|
||||
<section id="scheduling-quartz-cron">
|
||||
<title>Wiring up jobs using triggers and the <classname>SchedulerFactoryBean</classname></title>
|
||||
<para>
|
||||
We've created job details and jobs. We've also reviewed the convenience bean
|
||||
that allows to you invoke a method on a specific object. Of course, we still need
|
||||
to schedule the jobs themselves. This is done using triggers and a
|
||||
<classname>SchedulerFactoryBean</classname>. Several triggers are available
|
||||
within Quartz. Spring offers two subclassed triggers with convenient defaults:
|
||||
<classname>CronTriggerBean</classname> and <classname>SimpleTriggerBean</classname>.
|
||||
</para>
|
||||
<para>
|
||||
Triggers need to be scheduled. Spring offers a <classname>SchedulerFactoryBean</classname>
|
||||
that exposes triggers to be set as properties. <classname>SchedulerFactoryBean</classname>
|
||||
schedules the actual jobs with those triggers.
|
||||
</para>
|
||||
<para>Find below a couple of examples:</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="simpleTrigger" class="org.springframework.scheduling.quartz.SimpleTriggerBean">
|
||||
<!-- see the example of method invoking job above -->
|
||||
<property name="jobDetail" ref="jobDetail" />
|
||||
<!-- 10 seconds -->
|
||||
<property name="startDelay" value="10000" />
|
||||
<!-- repeat every 50 seconds -->
|
||||
<property name="repeatInterval" value="50000" />
|
||||
</bean>
|
||||
|
||||
<bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerBean">
|
||||
<property name="jobDetail" ref="exampleJob" />
|
||||
<!-- run every morning at 6 AM -->
|
||||
<property name="cronExpression" value="0 0 6 * * ?" />
|
||||
</bean>]]></programlisting>
|
||||
<para>Now we've set up two triggers, one running every 50 seconds with a starting delay of
|
||||
10 seconds and one every morning at 6 AM. To finalize everything, we need to set up the
|
||||
<classname>SchedulerFactoryBean</classname>:</para>
|
||||
<programlisting language="xml"><![CDATA[<bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
|
||||
<property name="triggers">
|
||||
<list>
|
||||
<ref bean="cronTrigger" />
|
||||
<ref bean="simpleTrigger" />
|
||||
</list>
|
||||
</property>
|
||||
</bean>]]></programlisting>
|
||||
<para>
|
||||
More properties are available for the <classname>SchedulerFactoryBean</classname> for you
|
||||
to set, such as the calendars used by the job details, properties to customize Quartz with,
|
||||
etc. Have a look at the
|
||||
<ulink url="http://static.springframework.org/spring/docs/2.5.x/api/org/springframework/scheduling/quartz/SchedulerFactoryBean.html">SchedulerFactoryBean Javadoc</ulink>
|
||||
for more information.
|
||||
</para>
|
||||
</section>
|
||||
</section>
|
||||
<section id="scheduling-jdk-timer">
|
||||
<title>Using JDK Timer support</title>
|
||||
<para>
|
||||
The other way to schedule jobs in Spring is to use JDK
|
||||
<classname>Timer</classname> objects. You can create custom timers or
|
||||
use the timer that invokes methods. Wiring timers is done using the
|
||||
<classname>TimerFactoryBean</classname>.
|
||||
</para>
|
||||
<section id="scheduling-jdk-timer-creating">
|
||||
<title>Creating custom timers</title>
|
||||
<para>
|
||||
Using the <classname>TimerTask</classname> you can create customer
|
||||
timer tasks, similar to Quartz jobs:
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[public class CheckEmailAddresses extends TimerTask {
|
||||
|
||||
private List emailAddresses;
|
||||
|
||||
public void setEmailAddresses(List emailAddresses) {
|
||||
this.emailAddresses = emailAddresses;
|
||||
}
|
||||
|
||||
public void run() {
|
||||
]]><lineannotation>// iterate over all email addresses and archive them</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
<para>
|
||||
Wiring it up is simple:
|
||||
</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="checkEmail" class="examples.CheckEmailAddress">
|
||||
<property name="emailAddresses">
|
||||
<list>
|
||||
<value>test@springframework.org</value>
|
||||
<value>foo@bar.com</value>
|
||||
<value>john@doe.net</value>
|
||||
</list>
|
||||
</property>
|
||||
</bean>
|
||||
|
||||
<bean id="scheduledTask" class="org.springframework.scheduling.timer.ScheduledTimerTask">
|
||||
]]><lineannotation><!-- wait 10 seconds before starting repeated execution --></lineannotation><![CDATA[
|
||||
<property name="delay" value="10000" />
|
||||
]]><lineannotation><!-- run every 50 seconds --></lineannotation><![CDATA[
|
||||
<property name="period" value="50000" />
|
||||
<property name="timerTask" ref="checkEmail" />
|
||||
</bean>]]></programlisting>
|
||||
<para>
|
||||
<emphasis>
|
||||
Note that letting the task only run once can be done by changing the
|
||||
<literal>period</literal> property to 0 (or a negative value).
|
||||
</emphasis>
|
||||
</para>
|
||||
</section>
|
||||
<section id="scheduling-jdk-timer-method-invoking-task">
|
||||
<title>Using the <classname>MethodInvokingTimerTaskFactoryBean</classname></title>
|
||||
<para>
|
||||
Similar to the Quartz support, the <classname>Timer</classname> support also features
|
||||
a component that allows you to periodically invoke a method:
|
||||
</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="doIt" class="org.springframework.scheduling.timer.MethodInvokingTimerTaskFactoryBean">
|
||||
<property name="targetObject" ref="exampleBusinessObject" />
|
||||
<property name="targetMethod" value="doIt" />
|
||||
</bean>]]></programlisting>
|
||||
<para>
|
||||
The above example will result in the <literal>doIt</literal> method being called on the
|
||||
<literal>exampleBusinessObject</literal> (see below):
|
||||
</para>
|
||||
<programlisting language="java"><![CDATA[public class BusinessObject {
|
||||
|
||||
]]><lineannotation>// properties and collaborators</lineannotation><![CDATA[
|
||||
|
||||
public void doIt() {
|
||||
]]><lineannotation>// do the actual work</lineannotation><![CDATA[
|
||||
}
|
||||
}]]></programlisting>
|
||||
<para>Changing the <literal>timerTask</literal> reference of the
|
||||
<classname>ScheduledTimerTask</classname> example to the bean <literal>doIt</literal>
|
||||
will result in the <literal>doIt</literal> method being executed on a fixed schedule.</para>
|
||||
</section>
|
||||
<section id="scheduling-jdk-timer-factory-bean">
|
||||
<title>Wrapping up: setting up the tasks using the <classname>TimerFactoryBean</classname></title>
|
||||
<para>The <classname>TimerFactoryBean</classname> is similar to the Quartz
|
||||
<classname>SchedulerFactoryBean</classname> in that it serves the same
|
||||
purpose: setting up the actual scheduling. The <classname>TimerFactoryBean</classname>
|
||||
sets up an actual <classname>Timer</classname> and schedules the tasks it has
|
||||
references to. You can specify whether or not daemon threads should be used.</para>
|
||||
<programlisting language="xml"><![CDATA[<bean id="timerFactory" class="org.springframework.scheduling.timer.TimerFactoryBean">
|
||||
<property name="scheduledTimerTasks">
|
||||
<list>
|
||||
]]><lineannotation><!-- see the example above --></lineannotation><![CDATA[
|
||||
<ref bean="scheduledTask" />
|
||||
</list>
|
||||
</property>
|
||||
</bean>]]></programlisting>
|
||||
</section>
|
||||
</section>
|
||||
|
||||
</chapter>
|
||||
Loading…
Reference in New Issue