最近有遇到定时任务的场景，本来想直接整个quartz，但是小场景不用大动作，就网上搜搜博客，摘了几个好的试了试,都挺好使。简单记录下学习学习.
1、Thread + sleep 最简单实现
class ThreadTask extends Thread{
public void run() {
while(true) {
try {
// to do task
Thread.sleep(1*60*1000);
} catch (Exception e) {
}
}
}
}
// 直接开启线程2、Timer + TimerTask ，注意Schedule() 和 scheduleAtFixedRate() 区别
@PostConstruct
public void init() {
//开启线程
testSchedule();
scheduleAtFixedRate();
}
/**
* 耗时任务结束后，按照正常间隔执行,固定延时
*/
private void testSchedule() {
TimerTask task = new TimerTask(){
@Override
public void run() {
try {
// to do task
} catch (Exception e) {
}
}
};
Long delay = 60 * 1000L;
Long period = 10 * 1000L;
Timer timer = new Timer();
timer.schedule(task, delay, period); //延时60s 首次执行，后搁10s 执行一次
}
/**
* 耗时任务结束后， 直接补上耗时期间所欠下的任务，固定频率
*/
private void scheduleAtFixedRate() {
TimerTask task = new TimerTask(){
@Override
public void run() {
try {
// to do task
} catch (Exception e) {
}
}
};
Long delay = 60 * 1000L;
Long period = 10 * 1000L;
Timer timer = new Timer();
//延时60s 首次执行，后搁10s 执行一次
timer.scheduleAtFixedRate(task, delay, period);
/*** 定制每日1:00执行方法 ***/
long PERIOD_DAY = 24*60*60*1000;
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.HOUR_OF_DAY, 1);
calendar.set(Calendar.MINUTE, 0);
calendar.set(Calendar.SECOND, 0);
//执行定时任务的时间 < 当前的时间
// 则定时任务的时间+1，以便此任务在下个时间点执行。如果不加一天，任务会立即执行。
Date date=calendar.getTime();
if (date.before(new Date())) {
calendar.add(Calendar.DAY_OF_MONTH, 1);
date = calendar.getTime();
}
Timer timer2 = new Timer();
timer2.scheduleAtFixedRate(task,date,PERIOD_DAY);
}
3、线程池
@PostConstruct
public void init() {
testScheduledExecutorService()
}
public void testScheduledExecutorService() {
Runnable runnable = new Runnable() {
public void run() {
try {
// to do task
} catch (Exception e) {
}
}
};
ScheduledExecutorService service = Executors.newScheduledThreadPool(10);
/*** 延时60s执行，周期10s ***/
service.scheduleAtFixedRate(runnable, 60*1000, 10*1000, TimeUnit.MILLISECONDS);
/*** 定制每日1:00执行方法 ***/
long oneDay = 24 * 60 * 60 * 1000;
long initDelay = getTimeMillis("01:00:00") - System.currentTimeMillis();
initDelay = initDelay > 0 ? initDelay : oneDay + initDelay;
service.scheduleAtFixedRate(runnable, initDelay, oneDay, TimeUnit.MILLISECONDS);
}
private static long getTimeMillis(String time) {
try {
DateFormat dateFormat = new SimpleDateFormat("yy-MM-dd HH:mm:ss");
DateFormat dayFormat = new SimpleDateFormat("yy-MM-dd");
Date curDate = dateFormat.parse(dayFormat.format(new Date()) + " " + time);
return curDate.getTime();
} catch (ParseException e) {
e.printStackTrace();
}
return 0;
}
4、spring 的 ThreadPoolTaskScheduler
4.1 SchedulerConfiguration配置类
@Configuration
//@EnableAsync
public class SchedulerConfiguration {
// + @EnableAsync 可解决耗时问题
@Bean
public TaskScheduler taskScheduler(){
ThreadPoolTaskScheduler taskScheduler = new ThreadPoolTaskScheduler();
taskScheduler.setPoolSize(10);
taskScheduler.initialize();
return taskScheduler;
}
}4.2 任务task
@Component
// @Async
//@PropertySource(value = "classpath:application.yml") 可省略
public class Task {
/**
* 延时加载，耗时任务，会影响加载！
* + @Async 可解决耗时任务
*/
/*** 周期10s ***/
@Scheduled(cron = "*/10 * * * * ?")
public void task() {
// to do task
}
/*** 定制每日1:00执行方法 ***/
@Scheduled(cron = "0 0 1 1/1 * ?")
public void task2() {
// to do task
}
//@Scheduled(cron = "${task.cron}") 把cron写在配置文件中
public void task3() {
// to do task
}
}5、spring 的 ThreadPoolTaskExecutor
5.1 配置类 AsyncConfiguration
@Configuration
@EnableAsync
public class AsyncConfiguration {
private int corePoolSize = 10;
private int maxPoolSize = 100;
private int queueCapacity = 20;
@Bean
public Executor taskExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(corePoolSize);
executor.setMaxPoolSize(maxPoolSize);
executor.setQueueCapacity(queueCapacity);
executor.initialize();
return executor;
}
}5.2 任务 task
@Component
@Async
public class Task {
/**
* 异步可解决耗时问题
*
*/
/*** 周期10s ***/
@Scheduled(cron = "*/10 * * * * ?")
public void task() {
// to do task
}
/*** 定制每日1:00执行方法 ***/
@Scheduled(cron = "0 0 1 1/1 * ?")
public void task2() {
// to do task
}
}参考博客：
https://blog.csdn.net/u010963948/article/details/52946268
https://blog.csdn.net/a718515028/article/details/80396102
在线cron http://cron.qqe2.com/