导读
由于项目需要,需要使用定时任务推送数据,而且有时候需要开启多个定时任务去跑,后面研究了下定时任务的操作技能,有两张,一种是异步的(推荐),线程安全,一种不是异步的,非线程安全,假如有一个挂了,会影响后面输出。
使用
说明
SpringBoot项目开启定时任务,需要在启动类上添加注解 @EnableScheduling
,不然的话,就算项目启动,定时任务还是不可以使用。
异步定时任务
异步配置类
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;
/**
* 异步开启定时任务配置
*
* @date 2020/6/24 15:46
*/
@Configuration
@EnableAsync //开启异步事件的支持
public class AsyncConfig {
/**
* 核心线程数
*/
private int corePoolSize = 20;
/**
* 最大线程数
*/
private int maxPoolSize = 220;
/**
* 队列最大长度
*/
private int queueCapacity = 20;
/**
* 线程池维护线程所允许的空闲时间
*/
private int keepAliveSeconds = 20;
/**
* 线程池对拒绝任务(无线程可用)的处理策略
* <p>
* rejectedExectutionHandler参数字段用于配置绝策略,常用拒绝策略如下
* <p>
* AbortPolicy:用于被拒绝任务的处理程序,它将抛出RejectedExecutionException
* <p>
* CallerRunsPolicy:用于被拒绝任务的处理程序,它直接在execute方法的调用线程中运行被拒绝的任务。
* <p>
* DiscardOldestPolicy:用于被拒绝任务的处理程序,它放弃最旧的未处理请求,然后重试execute。
* <p>
* DiscardPolicy:用于被拒绝任务的处理程序,默认情况下它将丢弃被拒绝的任务。
*/
private ThreadPoolExecutor.AbortPolicy rejectedExecutionHandler = new ThreadPoolExecutor.AbortPolicy();
@Bean
public Executor taskExecutor() {
ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
executor.setCorePoolSize(corePoolSize);
executor.setMaxPoolSize(maxPoolSize);
executor.setQueueCapacity(queueCapacity);
executor.setKeepAliveSeconds(keepAliveSeconds);
executor.setRejectedExecutionHandler(rejectedExecutionHandler);
executor.initialize();
return executor;
}
}
启动定时任务
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
/**
* 异步开启定时任务
*
* @date 2020/6/24 15:46
*/
@Component
@Async //启动异步调用
public class TinfoDemoScheduleTask {
private static final Logger logger = LoggerFactory.getLogger(TinfoDemoScheduleTask.class);
@Scheduled(cron = "0/1 * * * * *")
public void scheduled() {
logger.info("测试cron表达式,线程名称:{}", Thread.currentThread().getName());
}
@Scheduled(fixedRate = 1000)
public void scheduledDemo1() {
logger.info("测试fixedRate,线程名称:{}", Thread.currentThread().getName());
}
@Scheduled(fixedDelay = 1000)
public void scheduledDemo2() {
logger.info("测试fixedDelay,线程名称:{}", Thread.currentThread().getName());
}
}
Console
2020-06-24 15:51:17.506 INFO 17092 --- [ taskExecutor-1] c.l.u.i.demo.TinfoDemoScheduleTask : 测试fixedRate,线程名称:taskExecutor-1
2020-06-24 15:51:17.506 INFO 17092 --- [ taskExecutor-2] c.l.u.i.demo.TinfoDemoScheduleTask : 测试fixedDelay,线程名称:taskExecutor-2
2020-06-24 15:51:18.001 INFO 17092 --- [ taskExecutor-3] c.l.u.i.demo.TinfoDemoScheduleTask : 测试cron表达式,线程名称:taskExecutor-3
2020-06-24 15:51:18.496 INFO 17092 --- [ taskExecutor-4] c.l.u.i.demo.TinfoDemoScheduleTask : 测试fixedRate,线程名称:taskExecutor-4
2020-06-24 15:51:18.500 INFO 17092 --- [ taskExecutor-5] c.l.u.i.demo.TinfoDemoScheduleTask : 测试fixedDelay,线程名称:taskExecutor-5
2020-06-24 15:51:19.001 INFO 17092 --- [ taskExecutor-6] c.l.u.i.demo.TinfoDemoScheduleTask : 测试cron表达式,线程名称:taskExecutor-6
2020-06-24 15:51:19.496 INFO 17092 --- [ taskExecutor-7] c.l.u.i.demo.TinfoDemoScheduleTask : 测试fixedRate,线程名称:taskExecutor-7
非异步定时任务
启动定时任务
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
@Component
public class TinfoDemoScheduleTaskTwo {
private static final Logger logger = LoggerFactory.getLogger(TinfoDemoScheduleTaskTwo.class);
@Scheduled(cron = "0/1 * * * * *")
public void scheduled() {
logger.info("测试cron表达式,线程名称:{}", Thread.currentThread().getName());
}
@Scheduled(fixedRate = 1000)
public void scheduledDemo1() {
logger.info("测试fixedRate,线程名称:{}", Thread.currentThread().getName());
}
@Scheduled(fixedDelay = 1000)
public void scheduledDemo2() {
logger.info("测试fixedDelay,线程名称:{}", Thread.currentThread().getName());
}
}
Console
2020-06-24 16:05:32.277 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试fixedRate,线程名称:scheduling-1
2020-06-24 16:05:32.282 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试fixedDelay,线程名称:scheduling-1
2020-06-24 16:05:33.002 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试cron表达式,线程名称:scheduling-1
2020-06-24 16:05:33.276 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试fixedRate,线程名称:scheduling-1
2020-06-24 16:05:33.283 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试fixedDelay,线程名称:scheduling-1
2020-06-24 16:05:34.002 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试cron表达式,线程名称:scheduling-1
2020-06-24 16:05:34.277 INFO 9400 --- [ scheduling-1] c.l.u.i.demo.TinfoDemoScheduleTaskTwo : 测试fixedRate,线程名称:scheduling-1
总结
在项目中还是使用异步的比较好,就算一个出现问题,其他的还是能执行,但是如果使用非异步的,那么当出现一个死掉,那么其他的也就停止执行了。
END
搞定~