Different implementations parse Java timers

Java timer (Timer) is a tool used to perform tasks at a specific time. It can be used to perform scheduled tasks, scheduled tasks, periodic tasks, etc. The underlying implementation of Java timers is implemented through the Timer class, which provides a variety of ways to schedule scheduled tasks.

1. Implementation based on Timer class:

The Timer class is a basic timer class provided by Java. You can use the Timer class to create scheduled tasks and arrange the execution of tasks. . The following is a simple example based on the Timer class:

import java.util.Timer;
import java.util.TimerTask;

public class TimerDemo {
    public static void main(String[] args) {
        Timer timer = new Timer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                // 定时任务的逻辑处理
                System.out.println("定时任务执行！");
            }
        }, 1000, 2000); // 延迟1秒后开始执行，每2秒执行一次
    }
}

In the above example, the execution of scheduled tasks is scheduled through the schedule method of the Timer class. You can specify the delayed execution time and repeat execution interval of the task.

2. Implementation based on ScheduledExecutorService:

Java provides a more advanced scheduled task scheduling method through the ScheduledExecutorService interface. ScheduledExecutorService can be understood as a delay queue that can be used to schedule the execution of tasks. The following is an example based on ScheduledExecutorService:

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class ScheduledExecutorServiceDemo {
    public static void main(String[] args) {
        ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
        executorService.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                // 定时任务的逻辑处理
                System.out.println("定时任务执行！");
            }
        }, 1, 2, TimeUnit.SECONDS); // 延迟1秒后开始执行，每2秒执行一次
    }
}

In the above example, the execution of scheduled tasks is scheduled through the scheduleAtFixedRate method of ScheduledExecutorService. You can specify the initial delayed execution time and repeat execution interval of the task.

3. Spring-based scheduled tasks:

In addition to Java's native timer, you can also use the scheduled task scheduling function provided by the Spring framework. Spring's scheduled tasks mark the execution time and frequency of the task through the @Scheduled annotation. The following is an example of a scheduled task based on Spring:

import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;

@Component
public class ScheduledTask {
    @Scheduled(initialDelay = 1000, fixedDelay = 2000) // 延迟1秒后开始执行，每2秒执行一次
    public void runTask() {
        // 定时任务的逻辑处理
        System.out.println("定时任务执行！");
    }
}

In the above example, the execution time and frequency of the scheduled task are marked by adding the @Scheduled annotation to the method. You can specify an initial delayed execution time for a task and a time interval between executions.

The above are different implementations of Java timers, which are based on Timer class, ScheduledExecutorService and Spring scheduled tasks. Each implementation method has its own applicable scenarios, and developers can choose the appropriate method to schedule scheduled tasks according to specific needs.

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