我有一个简单的java程序,用于生成元素并在特定时间每X秒将它们插入数据库中。
生成是通过scheduleAtFixedRate
完成的。只有其中之一。
我希望我的程序在计划任务结束时完全退出。为此,我在取消任务时使用 System.exit()
,但这是执行此操作的正确方法吗?
这是我当前的代码:
public static void main(String[] args) throws InterruptedException {
c = generateDbConnection(url, user, password);
if (c != null) {
s = generateDbStatement(c);
} else {
System.out.println("ERROR");
return;
}
initialTimestamp = new Date();
TimeUnit.SECONDS.sleep(1);
generateForAnHour();
}
private final static ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
/**
* Generator thread handler Uses Statement from main function
*/
public static void generateForAnHour() {
final Runnable runner = new Runnable() {
public void run() {
String[][] data = new String[numberOfIds][2];
for (int i = 0; i < numberOfIds; i++) {
data[i] = generateDevice();
insertDevice(s, data[i][0], data[i][1]);
}
quantityOfIds += numberOfIds;
}
};
final ScheduledFuture<?> generatorHandle = scheduler.scheduleAtFixedRate(runner, 0, 5, TimeUnit.SECONDS);
scheduler.schedule(new Runnable() {
public void run() {
generatorHandle.cancel(true);
System.out.println("Scheduled ID generator terminated.");
System.exit(0); //TODO Is it really correct way to do it
}
}, timeToRun, TimeUnit.SECONDS);
}
最佳答案
如果程序还有更多功能,我不确定这是否是停止执行程序的正确方法,但我个人认为这是一种不错的方法。 :D
因此,事实证明,ScheduledExecutorService
似乎使用其默认的 ThreadFactory
创建非守护线程,也许我们需要为其提供一个守护线程。
但是,如果我们要调用 ExecutorService#shutdown
或强制的 ExecutorService#shutdownNow
,它将停止这两个任务的执行,从而删除该线程阻止应用程序结束其工作:
private final static ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
public static void main(String[] args) {
// Some service code here
generateForAnHour();
}
public static void generateForAnHour() {
// Some code that does work
final Runnable runner = () -> System.out.println("Running...");
final ScheduledFuture<?> generatorHandle = scheduler.scheduleAtFixedRate(runner, 0, 1, TimeUnit.SECONDS);
// Code that interrupts the worker after a specified time
scheduler.schedule(scheduler::shutdown, 5, TimeUnit.SECONDS);
}
输出:
Running...
Running...
Running...
Running...
Running...
Running...
Process finished with exit code 0
我希望这会有所帮助。 :D
关于java - 当计划的进程完成时,如何正确终止我的java程序?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59427598/