Question

Is it possible to adjust the number of threads used by the Spring container’s task support?

Answer 1

If you want to adjust it at runtime, then I believe your only choice is to do it programatically.

Inject a java.util.concurrent.ExecutorServiceinto Spring’s task support like this:

<bean id="executorService" class="java.util.concurrent.Executors"
    factory-method="newFixedThreadPool">
    <constructor-arg value="5" />
</bean>

<task:annotation-driven executor="executorService" />

Then you can adjust the threads used by the ExecutorService like this:

@Inject
ExecutorService executorService;

public void adjustPoolSize() {
    ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) executorService;
    threadPoolExecutor.setMaximumPoolSize(10);
    threadPoolExecutor.setCorePoolSize(20);
}

I have written more about concurrency with Spring here.