Question

Right now I have one bean with a @Scheduled method working fine; it’s declared in my applicationContext.xml.

<!-- some JPA stuff -->

<bean id="aWorkingBean" class="some.package.WorkingBean">
    <property name="someDAO" ref="someDAO" />
</bean>

<task:annotation-driven scheduler="myScheduler" />
<task:scheduler id="myScheduler" pool-size="10" />

What I’m trying to do is programmatically schedule another method (e.g. loading some annotated class and inject its dependencies) upon request. Something like:

WebApplicationContext ctx = ContextLoader.getCurrentWebApplicationContext();
BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(NonWorkingBean.class);
// add DAO references...
ctx.registerBeanDefinition("nonWorkingBean", builder.getBeanDefinition()); // <-- this doesn't work

Obviously it doesn’t work because the XmlWebApplicationContext is read-only and has no registerBeanDefinition method. Is there any other way to achieve this?

I’m using Tomcat 6.0.29 and Spring 3.0.4

Answer 1

<task:scheduler> and @Scheduled is really just a convenience approach to scheduling static tasks. It’s not really suitable for dynamic scheduling. Yes, you can make it work, but it’s going to be awkward.

When you put <task:scheduler id="myScheduler"> into your config, Spring creates a TaskScheduler bean called myScheduler. This can be injected into your own beans, and can be invoked programmatically in order to schedule new tasks. You’ll need to create a Runnable to pass to the TaskScheduler, but that should be simple enough.