EJB 3.1 Singleton Session Bean @PreDestroy method not called
Hello, All
I have a Singleton Session Bean executing background tasks:
@Singleton
@ConcurrencyManagement(ConcurrencyManagementType.BEAN)
@TransactionManagement(TransactionManagementType.BEAN)
@Startup
public class TaskQueue {
private static final Logger LOGGER = Logger.getLogger("TaskQueue");
@Resource
private SessionContext sessionContext;
private final ArrayList<Runnable> tasks = new ArrayList<Runnable>();
private boolean running = false;
@PostConstruct
public void postConstruct() {
LOGGER.info("postConstruct");
running = true;
sessionContext.getBusinessObject(TaskQueue.class).taskLoop();
}
@PreDestroy
public void preDestroy() {
LOGGER.info("preDestroy");
running = false;
synchronized (tasks) {
tasks.notifyAll();
}
}
public void addTask(Runnable r) {
synchronized (tasks) {
tasks.add(r);
tasks.notifyAll();
}
}
@Asynchronous
public void taskLoop() {
while (running) {
Runnable task;
synchronized (tasks) {
LOGGER.info("Fetching next task...");
if (tasks.isEmpty()) {
try {
LOGGER.info("Task queue is empty. Waiting...");
tasks.wait();
LOGGER.info("Resumed");
continue;
} catch (InterruptedException e) {
break;
}
}
task = tasks.remove(0);
}
LOGGER.info("Executing task...");
task.run();
}
running = false;
LOGGER.info("Task queue exited");
}
}
When I tried to stop the module, undeploy the module, or stop the server, the preDestroy() method did not get called, and the stopping/undeployment process won't proceed. The only way to stop the server is to kill the Java process.
I am using Jboss EAP 6.0.
What's going wrong with my code? How to fix it, or what's the alternative way to do background task queue processing with EJB 3.1?
Thanks!
-
老y
