ScheduledThreadPoolExecutor 定时调度

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/lsshlsw/article/details/79101772

定时器中 Timer 有单线程等缺陷，quartz依赖太重， 用 ScheduledThreadPoolExecutor 又想实现定时调度，实现一个工具类计算初次调度时间即可。

import java.util.concurrent._

val task = new Runnable {
    override def run(): Unit = try {
      doSomething()
    }catch {
      case e: Exception => e.printStackTrace()
    }
}

val ex = new ScheduledThreadPoolExecutor(1)
//晚上10点半开始调度，每天调度一次
ex.scheduleAtFixedRate(task, DateHelper.calcDelay(22, 30, 0), DateHelper.ONE_DAY, TimeUnit.SECONDS)

DateHelper

import java.util.Calendar

object DateHelper {

  val ONE_DAY = 60 * 60 * 24

  /**
    * 计算下次调度开始的时间，单位为秒,24小时制
    **/
  def calcDelay(hour: Int, minute: Int, second: Int): Long = {
    if (!(0 <= hour && hour <= 23 && 0 <= minute && minute <= 59 && 0 <= second && second <= 59)) {
      throw new IllegalArgumentException()
    }

    val curTime = getCurTime()
    val targetTime = getTargetTime(hour, minute, second)

    //如果已经过了执行时间，执行时间变更为下一天该时段
    val delayTime = if (curTime < targetTime) {
      targetTime - curTime
    } else {
      val cal = Calendar.getInstance()
      cal.setTimeInMillis(targetTime)
      cal.add(Calendar.DATE, 1)
      cal.getTimeInMillis - curTime
    }
    delayTime / 1000
  }

  //获取当前的时间
  private def getCurTime(): Long = {
    val cal = Calendar.getInstance()
    cal.getTimeInMillis
  }

  //获取下次执行的时间
  private def getTargetTime(hour: Int, minute: Int, second: Int): Long = {
    val cal = Calendar.getInstance()
    cal.set(Calendar.HOUR_OF_DAY, hour)
    cal.set(Calendar.MINUTE, minute)
    cal.set(Calendar.SECOND, second)
    cal.getTimeInMillis
  }
}