Java下SpringBoot创建定时任务详解

@Configuration //1.主要用于标记配置类，兼备Component的效果。
@EnableScheduling // 2.开启定时任务
public class SaticScheduleTask {
 //3.添加定时任务
 @Scheduled(cron = "0/5 * * * * ?")
 //或直接指定时间间隔，例如：5秒
 //@Scheduled(fixedRate=5000)
 private void configureTasks() {
 System.err.println("执行静态定时任务时间: " + LocalDateTime.now());
 }
}

<parent>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter</artifactId>
 <version>2.0.4.RELEASE</version>
 </parent>

 <dependencies>
 <dependency><!--添加Web依赖 -->
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
 </dependency>
 <dependency><!--添加MySql依赖 -->
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
 </dependency>
 <dependency><!--添加Mybatis依赖 配置mybatis的一些初始化的东西-->
  <groupId>org.mybatis.spring.boot</groupId>
  <artifactId>mybatis-spring-boot-starter</artifactId>
  <version>1.3.1</version>
 </dependency>
 <dependency><!-- 添加mybatis依赖 -->
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
  <version>3.4.5</version>
  <scope>compile</scope>
 </dependency>
 </dependencies>

DROP DATABASE IF EXISTS `socks`;
CREATE DATABASE `socks`;
USE `SOCKS`;
DROP TABLE IF EXISTS `cron`;
CREATE TABLE `cron` (
 `cron_id` varchar(30) NOT NULL PRIMARY KEY,
 `cron` varchar(30) NOT NULL 
);
INSERT INTO `cron` VALUES ('1', '0/5 * * * * ?');

spring:
 datasource:
 url: jdbc:mysql://localhost:3306/socks
 username: root
 password: 123456

@Configuration //1.主要用于标记配置类，兼备Component的效果。
@EnableScheduling // 2.开启定时任务
public class DynamicScheduleTask implements SchedulingConfigurer {

 @Mapper
 public interface CronMapper {
 @Select("select cron from cron limit 1")
 public String getCron();
 }

 @Autowired //注入mapper
 @SuppressWarnings("all")
 CronMapper cronMapper;

 /**
 * 执行定时任务.
 */
 @Override
 public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {

 taskRegistrar.addTriggerTask(
  //1.添加任务内容(Runnable)
  () -> System.out.println("执行动态定时任务: " + LocalDateTime.now().toLocalTime()),
  //2.设置执行周期(Trigger)
  triggerContext -> {
   //2.1 从数据库获取执行周期
   String cron = cronMapper.getCron();
   //2.2 合法性校验.
   if (StringUtils.isEmpty(cron)) {
   // Omitted Code ..
   }
   //2.3 返回执行周期(Date)
   return new CronTrigger(cron).nextExecutionTime(triggerContext);
  }
 );
 }

}

//@Component注解用于对那些比较中立的类进行注释；
//相对与在持久层、业务层和控制层分别采用 @Repository、@Service 和 @Controller 对分层中的类进行注释
@Component
@EnableScheduling // 1.开启定时任务
@EnableAsync // 2.开启多线程
public class MultithreadScheduleTask {

 @Async
 @Scheduled(fixedDelay = 1000) //间隔1秒
 public void first() throws InterruptedException {
  System.out.println("第一个定时任务开始 : " + LocalDateTime.now().toLocalTime() + "\r\n线程 : " + Thread.currentThread().getName());
  System.out.println();
  Thread.sleep(1000 * 10);
 }

 @Async
 @Scheduled(fixedDelay = 2000)
 public void second() {
  System.out.println("第二个定时任务开始 : " + LocalDateTime.now().toLocalTime() + "\r\n线程 : " + Thread.currentThread().getName());
  System.out.println();
 }
 }