所以基本上我对多线程非常陌生。 我想以不同的时间间隔安排 5 项任务。 所以我发现了提供调度的执行器服务。
以不同的时间间隔启动五个任务。我不确定是否可以做到。
并且一个或多个任务可能会同时启动。 所以我考虑为所有任务创建多个线程池。他们还会相撞吗？ 如果我启动多个线程池，我可能会遇到什么性能问题，也请对此进行指导..!
所以请帮忙!
public class NewScheduler {
public static final Logger logger = Logger.getLogger(NewScheduler.class.getName());
static ScheduledExecutorService scheduledExecutorService;
List<ExecuterSchedulerBean> list = new ArrayList<>();
FanMonitorDao fanMonitorDao;
public static void proceed(){
logger.info("NewScheduler || proceed || :-START");
List<Runnable> runnableList = new ArrayList<>();
NewScheduler scheduler = new NewScheduler();
runnableList.add(new ActiveLinkChecker());
runnableList.add(new SecondScheduler());
runnableList.add(new ThirdScheduler());
runnableList.add(new FourthScheduler());
runnableList.add(new FifthScheduler());
for(Runnable check : runnableList){
try {
scheduledExecutorService = Executors.newScheduledThreadPool(1);
if(check instanceof ActiveLinkChecker){
scheduler.schedulerTasks("linkChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("linkChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof SecondScheduler){
scheduler.schedulerTasks("secondChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("secondChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof ThirdScheduler){
scheduler.schedulerTasks("thirdChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("thirdChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof FourthScheduler){
scheduler.schedulerTasks("fourthChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("fourthChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof FifthScheduler){
scheduler.schedulerTasks("fifthChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("fifthChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}
} catch (SocketException e) {
logger.info("Error in SchedularTaskServlet in Scheduling batches :-" + e);
try {
scheduledExecutorService = Executors.newScheduledThreadPool(1);
if(check instanceof ActiveLinkChecker){
scheduler.schedulerTasks("linkChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("linkChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof SecondScheduler){
scheduler.schedulerTasks("secondChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("secondChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof ThirdScheduler){
scheduler.schedulerTasks("thirdChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("thirdChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof FourthScheduler){
scheduler.schedulerTasks("fourthChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("fourthChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof FifthScheduler){
scheduler.schedulerTasks("fifthChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("fifthChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}
} catch (Exception ex) {
logger.info("Error in SchedularTaskServlet in Scheduling batches :-" + ex, new Throwable());
e.printStackTrace();
}
e.printStackTrace();
} catch (SQLException e) {
logger.info("Error in SchedularTaskServlet in Scheduling batches :-" + e);
try {
scheduledExecutorService = Executors.newScheduledThreadPool(1);
if(check instanceof ActiveLinkChecker){
scheduler.schedulerTasks("linkChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("linkChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof SecondScheduler){
scheduler.schedulerTasks("secondChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("secondChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof ThirdScheduler){
scheduler.schedulerTasks("thirdChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("thirdChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof FourthScheduler){
scheduler.schedulerTasks("fourthChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("fourthChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}else if(check instanceof FifthScheduler){
scheduler.schedulerTasks("fifthChecker", check);
ExecuterSchedulerBean bean = new ExecuterSchedulerBean();
bean.setServiceName("fifthChecker");
bean.setScheduledExecutorService(scheduledExecutorService);
}
} catch (Exception ex) {
logger.info("Error in SchedularTaskServlet in Scheduling batches :-" + ex, new Throwable());
e.printStackTrace();
}
e.printStackTrace();
} catch (Exception e) {
logger.info("Error in SchedularTaskServlet in Scheduling batches :-" + e, new Throwable());
e.printStackTrace();
}
}
logger.info("NewScheduler || proceed || :-END");
}
private void schedulerTasks(String taskName, Runnable scheduler) throws SQLException, SocketException {
logger.debug("NewScheduler || schedulerTasks || :-START");
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy kk:mm");
Calendar cal = null;
int weekDay = 0, weekMin = 0, weekHr = 0, runDay = 0, runHr = 0, runMin = 0, runDelay = 0;
float runGap = 0;
String flag = null;
fanMonitorDao = new FanMonitorDaoImpl();
try {
SchedulerBean bean = fanMonitorDao.getScheduler(taskName);
flag = (("A").equalsIgnoreCase(bean.getSchedulerStatus())?"Y":"N").trim();
if (flag != null && flag.equalsIgnoreCase("Y")) {
cal = Calendar.getInstance();
weekDay = cal.get(Calendar.DAY_OF_WEEK);// get the Weekday , from 1 to 7
weekHr = cal.get(Calendar.HOUR_OF_DAY);// get the Weekday , from 0 to 23
weekMin = cal.get(Calendar.MINUTE);// get the Weekday , from 0 to 59
System.out.println("Current Week Day is :->" + weekDay + ", Week Hrs:->" + weekHr + ", Week Min:->" + weekMin);
runDay = (runDay=Integer.parseInt(bean.getSchedulerDay().trim())) == 0 ? weekDay : runDay;
runHr = (runHr=Integer.parseInt(bean.getSchedulerHrs().trim()))== 0 ? weekHr : runHr;
runMin = Integer.parseInt(bean.getSchedulerMin().trim());
runGap = Float.parseFloat(bean.getSchedulerGap().trim());
runDelay = Integer.parseInt(bean.getSchedulerDelay().trim());
runDay = (runDay >= weekDay) ? (runDay - weekDay) : runDay + (7 - weekDay);
runHr = (runHr >= weekHr) ? (runHr - weekHr) : runHr + (24 - weekHr);
runMin = (runMin >= weekMin) ? (runMin - weekMin) : runMin - weekMin;
System.out.println("Difference between current values and Property values are :-days:->" + runDay + " Hrs:->" + runHr + " Min:->" + runMin);
cal.setTime(sdf.parse(sdf.format(new Date())));
cal.add(Calendar.DATE, runDay);
cal.add(Calendar.HOUR, runHr);
cal.add(Calendar.MINUTE, runMin);
runDay = Integer.parseInt(String.valueOf((cal.getTimeInMillis() - (sdf.parse(sdf.format(new Date()))).getTime())));
System.out.println("Next First run time is :->" + runDay + "-->>" + runDelay * runGap * 60 * 60 * 1000);
@SuppressWarnings("unused")
ScheduledFuture<?> alarmFuture = scheduledExecutorService.scheduleWithFixedDelay(scheduler, (long) runDay, (long) ((long) runDelay * runGap * 60 * 60 * 1000), TimeUnit.MILLISECONDS);
}
} catch (Exception e) {
logger.info("Error in SchedularTaskServlet in Scheduling batches :-" + e, new Throwable());
e.printStackTrace();
}
logger.debug("NewScheduler || schedulerTasks || :-END");
}
}
最佳答案
原则上使用一个ScheduledExecutorService是没有问题的。此外，在同一时间点开始的任务应该不是问题。
根据任务的数量以及它们的资源密集程度，您可能最终会耗尽线程(或 CPU 或 IO ..)，此时任务可能会延迟。但您无法通过创建新的 ScheduledExecutorService 来解决这个问题。
只有当您想要将任务彼此隔离时，创建多个此类服务才有意义。例如，您有一个非常重要的任务，因此您为此任务创建了一个线程池大小为 1 的服务。如果您现在注意您的应用程序(包括用于所有其他任务的 ScheduledExecutorService)，则该任务应该始终能够在计划时间执行。请注意，实际上线程的整体利用率会因此而降低，因此整体的时效性和吞吐量会受到影响，因为一个线程基本上是为高优先级任务保留的。
关于java - java中可以有多个调度线程池吗？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/36442910/