问题
I'm not an expert, just a beginner. So I kindly ask that you write some code for me.
If I have two classes, CLASS A
and CLASS B
, and inside CLASS B
there is a function called funb()
. I want to call this function from CLASS A
every ten minutes.
You have already given me some ideas, however I didn't quite understand.
Can you post some example code, please?
回答1:
Have a look at the ScheduledExecutorService:
Here is a class with a method that sets up a ScheduledExecutorService to beep every ten seconds for an hour:
import static java.util.concurrent.TimeUnit.*;
class BeeperControl {
private final ScheduledExecutorService scheduler =
Executors.newScheduledThreadPool(1);
public void beepForAnHour() {
final Runnable beeper = new Runnable() {
public void run() { System.out.println("beep"); }
};
final ScheduledFuture<?> beeperHandle =
scheduler.scheduleAtFixedRate(beeper, 10, 10, SECONDS);
scheduler.schedule(new Runnable() {
public void run() { beeperHandle.cancel(true); }
}, 60 * 60, SECONDS);
}
}
回答2:
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
public class ClassExecutingTask {
long delay = 10 * 1000; // delay in milliseconds
LoopTask task = new LoopTask();
Timer timer = new Timer("TaskName");
public void start() {
timer.cancel();
timer = new Timer("TaskName");
Date executionDate = new Date(); // no params = now
timer.scheduleAtFixedRate(task, executionDate, delay);
}
private class LoopTask extends TimerTask {
public void run() {
System.out.println("This message will print every 10 seconds.");
}
}
public static void main(String[] args) {
ClassExecutingTask executingTask = new ClassExecutingTask();
executingTask.start();
}
}
回答3:
Try this. It will repeat the run() function every set minutes. To change the set minutes, change the MINUTES variable
int MINUTES = 10; // The delay in minutes
Timer timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() { // Function runs every MINUTES minutes.
// Run the code you want here
CLASSB.funcb(); // If the function you wanted was static
}
}, 0, 1000 * 60 * MINUTES);
// 1000 milliseconds in a second * 60 per minute * the MINUTES variable.
Don't forget to do the imports!
import java.util.Timer;
import java.util.TimerTask;
For more info, go here:
http://docs.oracle.com/javase/7/docs/api/java/util/Timer.html http://docs.oracle.com/javase/7/docs/api/java/util/TimerTask.html
回答4:
public class datetime {
public String CurrentDate() {
java.util.Date dt = new java.util.Date();
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String currentTime = sdf.format(dt);
return currentTime;
}
public static void main(String[] args) {
class SayHello extends TimerTask {
datetime thisObj = new datetime();
public void run() {
String todaysdate = thisObj.CurrentDate();
System.out.println(todaysdate);
}
}
Timer timer = new Timer();
timer.schedule(new SayHello(), 0, 5000);
}
}
回答5:
Solution with Java 8
ClassB b = new ClassB();
ScheduledExecutorService executor = Executors.newScheduledThreadPool(1);
Runnable task = () -> {
b.funb();
};
executor.scheduleWithFixedDelay(task, 0, 10, TimeUnit.MINUTES);
来源:https://stackoverflow.com/questions/1220975/calling-a-function-every-10-minutes