我有一个执行后台任务的单例会话 Bean:
@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");
}
}
当我尝试停止模块、取消部署模块或停止服务器时,preDestroy()
没有调用该方法,并且停止/取消部署过程不会继续。停止服务器的唯一方法是终止 Java 进程。
我正在使用 Jboss EAP 6.0。
我的代码出了什么问题?如何修复它,或者使用 EJB 3.1 进行后台任务队列处理的替代方法是什么?