I have the following configutation:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:task="http://www.springframework.org/schema/task"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.0.xsd">
<context:component-scan base-package="com.abc" />
<task:annotation-driven executor="executor"/>
<task:executor id="executor" pool-size="2"/>
</beans>
Then the following class
public class SomeClassImpl implements SomeClass {
@Async
@Override // overridden from the interface
public void doSomething(){
System.out.println("doing something async");
}
}
A test:
@ContextConfiguration("classpath:test-config.xml") // with the xml config above
@RunWith(value = SpringJUnit4ClassRunner.class)
public class SomeClassTest {
@Autowired
private SomeClass someClass;
@Test
public void testSomething() throws Exception {
System.out.println("Calling doSomething");
someClass.doSomething();
Thread.sleep(5000);
}
}
When I ran the test, everything worked as expected. But then I attached the debugger to step through what is actually happening when someClass.doSomething() is called and i noticed the following:
Why is it that 4 threads are being created by a SimpleAsyncTaskExecutor? I know that if I remove the executor property from the task:annotation-driven xml element, the AsyncExecutionInterceptor will use the SimpleAsyncTaskExecutor. But since I have declared a task executor and referenced it from the annotation-driven element, why is a SimpleAsyncTaskExecutor being created?
