public synchronized void stop() {
        if (!started) {
            return;
        }
        try {
            if (future != null) {
                future.cancel(true);
                future = null;
            }
            if (scheduledExecutorService != null) {
                scheduledExecutorService.shutdownNow();
                scheduledExecutorService = null;
            }
        } catch (Throwable t) {
            LOGGER.warn(t.getMessage(), t);
        } finally {
            SCHEDULED_SERVICE_MAP.remove(this);
            started = false;
        }
    }
public synchronized void stop ( ) { if ( ! started ) { return ; } try { if ( future != null ) { future . cancel ( true ) ; future = null ; } if ( scheduledExecutorService != null ) { scheduledExecutorService . shutdownNow ( ) ; scheduledExecutorService = null ; } } catch ( Throwable t ) { LOGGER . warn ( t . getMessage ( ) , t ) ; } finally { SCHEDULED_SERVICE_MAP . remove ( this ) ; started = false ; } }
停止执行定时任务，还可以重新start