Java定时器怎么实现？Timer和线程池方法全攻略

void schedule(TimerTask task, Date time)

void schedule(TimerTask task, long delay)

void schedule(TimerTask task, long delay, long period) 

public void schedule(TimerTask task, Date firstTime, long period)

void scheduleAtFixedRate(TimerTask task, long delay, long period)

void scheduleAtFixedRate(TimerTask task, Date firstTime,long period)

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

/**
 * @author 沐雨橙风ιε
 * @version 1.0
 */
public class TimerExample {

    public static void main(String[] args) {
        // 创建定时器
        Timer timer = new Timer();

        // 创建定时器任务
        TimerTask task = new TimerTask() {
            @Override
            public void run() {
                System.out.println("Hello world!");
            }
        };

        timer.schedule(task, new Date()); // 马上执行一次
        timer.schedule(task, 1000); // 1秒后执行一次
        timer.schedule(task, new Date(), 2000); // 每2秒执行一次
        timer.schedule(task, 2000, 2000); // 2秒后每2秒执行一次

        timer.scheduleAtFixedRate(task, 3000, 3000); // 3秒后每3秒执行一次
        timer.scheduleAtFixedRate(task, new Date(), 4000); // 每3秒执行一次
    }

}

public ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit)

public <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit)

public ScheduledFuture<?> scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit)

public ScheduledFuture<?> scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit)

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

/**
 * @author 沐雨橙风ιε
 * @version 1.0
 */
public class ScheduledExecutorServiceExample {

    public static void main(String[] args) {
        Runnable task = new Runnable() {
            @Override
            public void run() {
                System.out.println("Hello world!");
            }
        };

        ScheduledExecutorService scheduledThreadPool = Executors.newScheduledThreadPool(2);

        scheduledThreadPool.schedule(task, 3, TimeUnit.SECONDS);// 3秒后执行一次任务
        scheduledThreadPool.schedule(new Callable<Object>() {
            @Override
            public Object call() throws Exception {
                return null;
            }
        }, 3, TimeUnit.SECONDS); // 3秒后执行一次任务

        scheduledThreadPool.scheduleAtFixedRate(task, 3, 3, TimeUnit.SECONDS); // 3秒后，每3秒执行一次任务
        scheduledThreadPool.scheduleWithFixedDelay(task, 3, 3, TimeUnit.SECONDS); // 3秒后，每3秒执行一次任务
    }

}

package cn.edu.sgu.www;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.scheduling.annotation.EnableScheduling;

/**
 * @author 沐雨橙风ιε
 * @version 1.0
 */
@EnableScheduling
@SpringBootApplication
public class TimerApplication {

    public static void main(String[] args) {
        SpringApplication.run(TimerApplication.class, args);
    }

}

package cn.edu.sgu.www.timer;

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

/**
 * @author 沐雨橙风ιε
 * @version 1.0
 */
@Component
public class TimerTask {

    /**
     * cron属性指定在每年的7月18日12:55:00执行一次定时任务
     * 对cron表达式感兴趣的可以去学习了解一下
     */
    @Scheduled(cron = "0 55 12 18 7 *")
    public void task() {
        System.out.println("执行定时任务...");
    }

}

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-quartz</artifactId>
</dependency>

package cn.edu.sgu.www.timer;

import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.springframework.stereotype.Component;

/**
 * @author 沐雨橙风ιε
 * @version 1.0
 */
@Component
public class QuartzJob implements Job {

    @Override
    public void execute(JobExecutionContext jobExecutionContext) {
        System.out.println("执行QuartzJob定时任务...");
    }

}

package cn.edu.sgu.www.config;

import cn.edu.sgu.www.timer.QuartzJob;
import org.quartz.*;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @author 沐雨橙风ιε
 * @version 1.0
 */
@Configuration
public class QuartzConfig {

    @Bean
    public JobDetail jobDetail() {
        return JobBuilder.newJob(QuartzJob.class)   // 绑定要执行的任务类
                .withIdentity("quartzJob")          // 设置任务名称
                .storeDurably()                     // 信息持久化
                .build();
    }

    @Bean
    public Trigger trigger(JobDetail jobDetail) {
        // 定义Cron表达式，每10秒触发一次
        CronScheduleBuilder cronScheduleBuilder = CronScheduleBuilder.cronSchedule("0/10 * * * * ?");

        return TriggerBuilder.newTrigger()
                .forJob(jobDetail)                   // 绑定JobDetail对象
                .withIdentity("trigger")             // 定义触发器名称
                .withSchedule(cronScheduleBuilder)   // 绑定Cron表达式
                .build();
    }

}