这篇文章主要介绍了Spring boot如何通过@Scheduled实现定时任务及多线程配置,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下 使
这篇文章主要介绍了Spring boot如何通过@Scheduled实现定时任务及多线程配置,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下
使用@Scheduled 可以很容易实现定时任务
spring boot的版本 2.1.6.RELEASE
package com.abc.demo.common;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.text.SimpleDateFormat;
import java.util.concurrent.TimeUnit;
@EnableScheduling
@Component
public class ScheduleSetting {
private final Logger logger = LoggerFactory.getLogger(Tasks.class);
@Scheduled(fixedRate = 10000, initialDelay = 2000)
public void scheduleRead() {
try {
long timeStamp = System.currentTimeMillis();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Thread thread = Thread.currentThread();
System.out.println("cron1任务开始,start=" + simpleDateFormat.format(timeStamp) + ", threadId=" + thread.getId() + ", threadName=" + thread.getName());
long endStamp = System.currentTimeMillis();
try {
TimeUnit.SECONDS.sleep(20);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("cron1任务正在运行的线程名称：" + thread.getName() + " 结束,start=" + simpleDateFormat.format(timeStamp) + ",end=" + simpleDateFormat.format(endStamp));
System.out.println("++++++++++++++++++++++++");
} catch (Exception e) {
logger.error(e.getMessage());
}
}
@Scheduled(fixedRate = 5000, initialDelay = 1000)
public void scheduleConvert() {
try {
long timeStamp = System.currentTimeMillis();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Thread thread = Thread.currentThread();
System.out.println("cron2任务开始,start=" + simpleDateFormat.format(timeStamp) + ", threadId=" + thread.getId() + ", threadName=" + thread.getName());
try {
TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
long endStamp = System.currentTimeMillis();
System.out.println("cron2任务正在运行的线程名称：" + thread.getName() + " 结束,start=" + simpleDateFormat.format(timeStamp) + ",end=" + simpleDateFormat.format(endStamp));
System.out.println("====================");
} catch (Exception e) {
logger.error(e.getMessage());
}
}
}
运行输出内容为
cron2任务开始,start=2019-10-11 17:31:52, threadId=34, threadName=scheduling-1 cron2任务正在运行的线程名称：scheduling-1 结束,start=2019-10-11 17:31:52,end=2019-10-11 17:32:02 ==================== cron1任务开始,start=2019-10-11 17:32:02, threadId=34, threadName=scheduling-1 cron1任务正在运行的线程名称：scheduling-1 结束,start=2019-10-11 17:32:02,end=2019-10-11 17:32:02 ++++++++++++++++++++++++ cron2任务开始,start=2019-10-11 17:32:22, threadId=34, threadName=scheduling-1 cron2任务正在运行的线程名称：scheduling-1 结束,start=2019-10-11 17:32:22,end=2019-10-11 17:32:32 ……
注：
cron2执行完后才会执行cron1
原因：
spring默认是以单线程执行任务调度
spring的定时任务默认最大运行线程数为1，多个任务执行起来时间会有问题
1.配置线程池
在配置文件application.properties中添加
# 线程池大小 spring.task.scheduling.pool.size=5 # 线程名前缀 spring.task.scheduling.thread-name-prefix=myScheduling-
输出内容变为
cron2任务开始,start=2019-10-11 17:34:48, threadId=34, threadName=myScheduling-1 cron1任务开始,start=2019-10-11 17:34:49, threadId=35, threadName=myScheduling-2 cron2任务正在运行的线程名称：myScheduling-1 结束,start=2019-10-11 17:34:48,end=2019-10-11 17:34:58 ==================== cron2任务开始,start=2019-10-11 17:34:58, threadId=34, threadName=myScheduling-1 cron2任务正在运行的线程名称：myScheduling-1 结束,start=2019-10-11 17:34:58,end=2019-10-11 17:35:08 ==================== cron2任务开始,start=2019-10-11 17:35:08, threadId=57, threadName=myScheduling-3 cron1任务正在运行的线程名称：myScheduling-2 结束,start=2019-10-11 17:34:49,end=2019-10-11 17:34:49 ……
注：
多线程下，cron1和cron2不用互相等待了，但是同一个任务还是需要等待的
2.并发
修改代码
package com.abc.demo.common;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.scheduling.annotation.Async;
import org.springframework.scheduling.annotation.EnableAsync;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import java.text.SimpleDateFormat;
import java.util.concurrent.TimeUnit;
@EnableScheduling
@Component
@EnableAsync
public class ScheduleSetting {
private final Logger logger = LoggerFactory.getLogger(Tasks.class);
@Async
@Scheduled(fixedRate = 10000, initialDelay = 2000)
public void scheduleRead() {
try {
long timeStamp = System.currentTimeMillis();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Thread thread = Thread.currentThread();
System.out.println("cron1任务开始,start=" + simpleDateFormat.format(timeStamp) + ", threadId=" + thread.getId() + ", threadName=" + thread.getName());
long endStamp = System.currentTimeMillis();
try {
TimeUnit.SECONDS.sleep(20);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("cron1任务正在运行的线程名称：" + thread.getName() + " 结束,start=" + simpleDateFormat.format(timeStamp) + ",end=" + simpleDateFormat.format(endStamp));
System.out.println("++++++++++++++++++++++++");
} catch (Exception e) {
logger.error(e.getMessage());
}
}
@Async
@Scheduled(fixedRate = 5000, initialDelay = 1000)
public void scheduleConvert() {
try {
long timeStamp = System.currentTimeMillis();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Thread thread = Thread.currentThread();
System.out.println("cron2任务开始,start=" + simpleDateFormat.format(timeStamp) + ", threadId=" + thread.getId() + ", threadName=" + thread.getName());
try {
TimeUnit.SECONDS.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
long endStamp = System.currentTimeMillis();
System.out.println("cron2任务正在运行的线程名称：" + thread.getName() + " 结束,start=" + simpleDateFormat.format(timeStamp) + ",end=" + simpleDateFormat.format(endStamp));
System.out.println("====================");
} catch (Exception e) {
logger.error(e.getMessage());
}
}
}
输出的内容
cron2任务开始,start=2019-10-11 17:39:53, threadId=57, threadName=task-1 cron1任务开始,start=2019-10-11 17:39:54, threadId=59, threadName=task-2 cron2任务开始,start=2019-10-11 17:39:58, threadId=61, threadName=task-3 cron2任务开始,start=2019-10-11 17:40:03, threadId=63, threadName=task-4 cron2任务正在运行的线程名称：task-1 结束,start=2019-10-11 17:39:53,end=2019-10-11 17:40:03 ==================== cron1任务开始,start=2019-10-11 17:40:04, threadId=64, threadName=task-5 cron2任务开始,start=2019-10-11 17:40:08, threadId=65, threadName=task-6 cron2任务正在运行的线程名称：task-3 结束,start=2019-10-11 17:39:58,end=2019-10-11 17:40:08 ==================== cron2任务开始,start=2019-10-11 17:40:13, threadId=66, threadName=task-7 cron2任务正在运行的线程名称：task-4 结束,start=2019-10-11 17:40:03,end=2019-10-11 17:40:13 ==================== cron1任务正在运行的线程名称：task-2 结束,start=2019-10-11 17:39:54,end=2019-10-11 17:39:54
说明：
- @EnableAsync开启多线程
- @Async标记其为一个异步任务
- 每个定时任务都是在通过不同的线程来处理，线程名的前缀成了task-
- 线程默认为10个
修改配置
spring.task.execution.thread-name-prefix=mytask- spring.task.execution.pool.core-size=5
重新运行的输出
cron2任务开始,start=2019-10-11 17:44:00, threadId=56, threadName=mytask-1 cron1任务开始,start=2019-10-11 17:44:01, threadId=57, threadName=mytask-2 cron2任务开始,start=2019-10-11 17:44:05, threadId=58, threadName=mytask-3 cron2任务开始,start=2019-10-11 17:44:10, threadId=59, threadName=mytask-4 cron2任务正在运行的线程名称：mytask-1 结束,start=2019-10-11 17:44:00,end=2019-10-11 17:44:10 ==================== cron1任务开始,start=2019-10-11 17:44:11, threadId=60, threadName=mytask-5 cron2任务正在运行的线程名称：mytask-3 结束,start=2019-10-11 17:44:05,end=2019-10-11 17:44:15 ==================== cron2任务开始,start=2019-10-11 17:44:15, threadId=58, threadName=mytask-3 cron2任务开始,start=2019-10-11 17:44:20, threadId=56, threadName=mytask-1 cron2任务正在运行的线程名称：mytask-4 结束,start=2019-10-11 17:44:10,end=2019-10-11 17:44:20 ==================== cron1任务正在运行的线程名称：mytask-2 结束,start=2019-10-11 17:44:01,end=2019-10-11 17:44:01
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