java - 如何管理/停止 spring 4 ConcurrentTaskScheduler

Question

我正在使用 Spring 4。我用它来定期为 Web 套接字执行任务:

private TaskScheduler scheduler = new ConcurrentTaskScheduler();

在我的课上:

@Configuration
@EnableWebSocketMessageBroker
@EnableScheduling
@Component
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

    @Autowired
    private SimpMessagingTemplate template;


    private TaskScheduler scheduler = new ConcurrentTaskScheduler();
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/simplemessages").withSockJS();
    }

    public void configureMessageBroker(MessageBrokerRegistry config) {

        config.enableSimpleBroker("/topic/", "/queue/");

        config.setApplicationDestinationPrefixes("/app");
    }


    @PostConstruct
    private void broadcastTimePeriodically() {


        scheduler.scheduleAtFixedRate(new Runnable() {
            public void run() {
                String statStr = "Server Response" + new Date();
                System.out.println("thread schedular run time :" + Hello.printTime());
                try {
                    template.convertAndSend("/topic/simplemessagesresponse", statStr);
                } catch (MessagingException e) {
                    System.err.println("!!!!!! websocket timer error :>" + e.toString());
                }

            }
        }, 4000));


}

@PreDestroy
private void destroyServices() {
    scheduler = null; // how to destroy ? 

}

public void configureClientInboundChannel(ChannelRegistration registration) {

}

public void configureClientOutboundChannel(ChannelRegistration registration) {
    registration.taskExecutor().corePoolSize(4).maxPoolSize(10);
}

public boolean configureMessageConverters(List < MessageConverter > arg0) {
    // TODO Auto-generated method stub
    return true;
}
@Override
public void configureWebSocketTransport(WebSocketTransportRegistration arg0) {

}
}

我想知道的事情:

1. 我发现调度程序在 4000 毫秒内运行了两次。它是怎么发生的，我该如何阻止它？

2. 我在 tomcat 中运行这个应用程序。如您所见，destroyServices() 方法需要销毁调度程序。这里的问题是，即使再次重启tomcat，之前运行的线程还在运行。因此，当 tomcat 即将关闭时，该线程也应该终止。我需要知道如何在 tomcat 发生故障或任何系统崩溃时销毁它？

Answer 1

以下代码片段来自@EnableScheduling的文档:

   @Configuration
   @EnableScheduling
   public class AppConfig implements SchedulingConfigurer {
       @Override
       public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
           taskRegistrar.setScheduler(taskExecutor());
       }

       @Bean(destroyMethod="shutdown")
       public Executor taskExecutor() {
           return Executors.newScheduledThreadPool(100);
       }
   }

我认为您应该获取名为 taskExecutor 的 bean(在本例中)并调用它的 shutdown(实际上取决于您的配置)方法。