//設(shè)置定時器開始時間
Date time = sdf.parse("2020-10-01 16:40:00");
//設(shè)置定時器
Timer timer = new Timer();
//第三個參數(shù)表示每隔多久循環(huán)一次
timer.schedule(new TimerTask() {
  @Override
 public void run() {
    System.out.println("嗨");
 }
}, time, 3000);

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://www.springframework.org/schema/beans
 https://www.springframework.org/schema/beans/spring-beans.xsd ">

<!-- 定時器-->
   <bean id="myTask" class="com.cjh.MyTask"></bean>
  <!-- 創(chuàng)建一個Spring提供好的計時器對象，用來做倒計時管控-->
   <bean id="taskExecutor" class="org.springframework.scheduling.quartz.MethodInvokingJobDetailFactoryBean">
     <property name="targetObject" ref="myTask"/>
     <property name="targetMethod" value="test"/>
   </bean>
   <!-- 觸發(fā)器-->
   <bean id="cronTrigger" class="org.springframework.scheduling.quartz.CronTriggerFactoryBean">
     <property name="jobDetail" ref="taskExecutor"/>
     <property name="cronExpression" value="30/5 41 18 * * ?"/>
   </bean>
  <!-- 管理觸發(fā)器對象的容器-->
   <bean class="org.springframework.scheduling.quartz.SchedulerFactoryBean">
    <property name="triggers">
       <list>
        <ref bean="cronTrigger"/>
       </list> 
    </property> 
   </bean>
</beans>

public class TestMain {
  public static void main(String[] args) throws MessagingException, ParseException {
    ApplicationContext context = new ClassPathXmlApplicationContext("ApplicationContext.xml");
 }
}