scheduleAtFixedRate精度
时间: 2023-11-24 18:41:18 浏览: 25
scheduleAtFixedRate方法的精度取决于系统的运行状况和负载情况。一般来说,它会尽量按照指定的间隔时间执行任务,但不能保证完全精确。如果任务的执行时间超过了指定的间隔时间,那么下一次任务的执行时间会相应地顺延。因此,如果要求任务具有更高的精确性,可以考虑使用scheduleWithFixedDelay方法。
相关问题
scheduleAtFixedRate
scheduleAtFixedRate is a method in the Java Timer class that allows you to schedule a task to be executed repeatedly at a fixed interval of time. This method takes four parameters:
1. A TimerTask object that represents the task to be executed.
2. A long value that specifies the delay before the first execution of the task.
3. A long value that specifies the interval between subsequent executions of the task.
4. A boolean value that determines whether the task should be executed even if the previous execution is still running.
The scheduleAtFixedRate method ensures that the task is executed at the specified interval even if the previous execution takes longer to complete than the specified interval. However, this can lead to overlapping executions of the task if the task takes longer to complete than the specified interval.
Here is an example of using the scheduleAtFixedRate method to schedule a task to be executed every 10 seconds:
```
Timer timer = new Timer();
TimerTask task = new TimerTask() {
public void run() {
System.out.println("Task executed at " + new Date());
}
};
timer.scheduleAtFixedRate(task, 0, 10000);
```
scheduleAtFixedRate 计数
scheduleAtFixedRate方法是Java中Timer类的一个方法,用于按固定的速率执行任务。它接受两个参数:一个TimerTask对象,表示要执行的任务,和一个long类型的参数,表示任务的初始延迟时间。该方法会以固定的速率重复执行任务,每次执行的时间间隔为参数中指定的时间。
下面是一个示例代码,演示了如何使用scheduleAtFixedRate方法进行计数:
```java
import java.util.Timer;
import java.util.TimerTask;
public class CountingTask extends TimerTask {
private int count = 0;
@Override
public void run() {
count++;
System.out.println("Count: " + count);
}
public static void main(String[] args) {
Timer timer = new Timer();
CountingTask countingTask = new CountingTask();
// 延迟1秒后开始执行任务,每隔2秒执行一次
timer.scheduleAtFixedRate(countingTask, 1000, 2000);
}
}
```
上述代码中,定义了一个CountingTask类,继承自TimerTask类,并重写了run方法。在run方法中,每次执行时,计数器count会自增,并输出当前的计数值。
在main方法中,创建了一个Timer对象和一个CountingTask对象。然后使用scheduleAtFixedRate方法,设置初始延迟时间为1秒,每隔2秒执行一次CountingTask任务。
运行上述代码,你将会看到每隔2秒输出一次计数值,示例中的输出结果如下:
```
Count: 1
Count: 2
Count: 3
...
```